What Size Powder Spray Booth Do You Need?

(Be sure to check out our article What Size Powder Coating Oven Do You Need? for more information on matching your powder coating equipment for best results.)

powder-spray-booth-with-true-hepa-filtrationJust like with your powder curing oven, your powder spray booth needs to be large enough to accommodate either the largest product you will routinely be coating or the largest batch of products you must coat in order to meet your shop’s throughput requirements. Your booth may need to be a bit larger than your oven if you are dealing with large parts, or it may be possible to use a smaller booth if you coat multiple small racks of parts before curing them all in one large batch. Regardless of the booth’s size, you need an appliance that is large enough to hold your products and provide enough space for the operator(s) to move and work efficiently.

Although this article focuses on batch coating processes, many of the concepts also apply to powder coating in a constant-process environment where parts are moved via conveyor instead of on rolling racks or carts. With both batch and automated lines, it is not uncommon for booths to be open-faced or to have ware openings instead of doors that seal the parts inside the powder coating booth. Unlike with conventional wet paint processes, contamination by airborne dust or debris is usually less problematic when powder coating.

Prevent Powder Contamination In Your Work Environment

checking-parts-for-powder-coating-consistencyDuring powder application, the powder that does not adhere to the part is called overspray. Overspray generally falls to the ground or is moved by the booth’s airflow and pulled into the filtration system, but only if the powder is sprayed inside the booth while the exhaust is operating. Spraying powder outside the booth or away from the filters can lead to powder contamination of nearby appliances (including your curing oven). The airborne powder is a nuisance dust that can travel throughout your workspace.

When sizing your powder spray booth, make sure that the booth is large enough to completely enclose the largest product you’ll be coating. This ensures that all the powder is being sprayed inside the booth, which eliminates powder contamination of the shop environment.

Add Interior Space To Improve Efficiency

room-to-work-in-a-powder-spray-boothThe largest product you are coating should easily fit inside the booth with extra room for each operator to both move himself and the powder coating gun around the part. Adding additional space gives your operator adequate room to work without jostling or bumping the product that is being coated. Prior to curing, applied powder media is fairly easy to remove. Any accidental contact with the part will require touch-up if not a total rework.

Besides adding room for the painters, you also need to allow room for your racks. Let’s say you have a 6’ tall part and you want to coat it in an 8’ tall booth. If the rack and hook cause the part to hang about 1’ from the ceiling of the booth, the painter is going to end up having to paint a portion of the part that is only 1’ off of the floor. To do this effectively can be slow and tedious, and this type of cramped working space contributes to fatigue.

Another issue is maintenance. In the scenario above, the top surface of the part being coated is only 1’ from the ceiling. This means that the booth’s ceiling and ceiling-mounted lights will be coated with powder overspray. After an hour of painting, the lights will have a film of powder over them—reducing illumination in the booth and causing the light coming from the fixtures to be tinted by the thin layer of powder as it passes through. This makes it harder for the painter to gauge coverage. Greater contamination by overspray also translates to greater cleaning costs and more down time as the booth must be frequently cleaned with compressed air or wiped down. The same problem can occur when spraying parts that are too close to the walls. It’s easy to dislodge accumulated powder and contaminate fresh parts, especially if the old powder on the wall is a significantly different color or gloss compared to the powder being applied to the parts.

If you are going to be using a single large rack per batch, we recommend that the powder spray booth be an additional 2′ – 6′ wider than the matching powder coating oven. This gives your painters room to work. We also suggest that you consider a booth that is 2’ taller than your oven to reduce cleaning hassles associated with powder covering your light fixtures. One of Reliant Finishing Systems’ most popular batch equipment packages is sold with an 8’H x 8’W x 25’D (interior) curing oven and an 8’H x 10’W x 25’D or 10’H x 10’W x 25’D (interior) powder spray booth for this very reason.

Determining Your Powder Spray Booth’s Footprint

Make sure you have enough available floor space to put the right size booth in your facility. Note any low ceilings, structural supports, posts or columns, or other obstructions that might restrict where your powder spray booth can be installed. Carefully planning the layout of your booth, oven ( and pretreatment appliances before you buy them can prevent headaches later.

While the overall footprint of most powder booths is similar to their listed interior dimensions, there are a couple things to keep in mind. Every powder spray booth comes with at least one integrated, attached or separate exhaust chamber that houses the filters and the exhaust fan system. Depending on the powder spray booth’s configuration, these exhaust chambers are attached to the rear of the booth or to one or both of the side walls. These exhaust chambers usually add an additional 4’ to 5’ of depth if attached to the rear, 4’ to 5’ of width if a single side wall has an exhaust, or 8’ to 10’ of additional width if both walls have exhaust units attached.

As an example, a standard model PSE81025 from Reliant Finishing Systems is a powder spray enclosure that is approximately 8’H x 10’W x 25’D inside. It comes with an exhaust chamber that is built into the rear of the booth enclosure. The overall exterior length of the booth is 28’10” including the exhaust unit.


The header panel adds approximately 2′ of extra height to the front of your powder spray booth.

Another space consideration is the header panel. The header panel is usually about 2’ tall and is added to the front of spray booths in order to keep airborne powder from drifting over the top of the booth and into the light fixtures. The header also assures that the light fixtures are adequately isolated from the booth interior to meet national codes, such as NFPA 33. The header panel is installed on the very front of the spray booth, above the main opening, and is typically only a couple inches deep, so you won’t have to account for its additional height over the entire appliance.

In addition to the total exterior dimensions of the powder spray booth, we suggest that you allow for at least 3’ of clearance around the booth in order to make installation and maintenance less costly and to meet common codes and regulations once the booth is installed.

Adjust Workflow With Different Booth Models

The type of powder spray booth you decide on can also greatly influence your powder coating system’s layout and workflow. Reliant Finishing Systems provides three different configurations of powder spray booths, shown below.

A STANDARD powder spray booth has an enclosed cabin with a filtered back wall. Many batch powder operations use standard booths and install them side-by-side with their powder coating oven (again, allowing for at least 3′ between appliances and the walls).

Remember: Some companies, especially those that primarily deal with wet paint booths like those used in automotive body shops, this design may be called a “crossflow” configuration to differentiate it from “downdraft” designs where the air travels from the ceiling into a metal basement or excavated pit under the booth before being exhausted.


Shown: a crossflow style powder spray booth. A crossflow style booth has an exhaust chamber on one side wall. A double crossflow would have an exhaust chamber on both side walls.

A CROSSFLOW powder spray booth usually does not have a back wall. Instead, it has the exhaust filters installed on one side wall. This creates a tunnel-style configuration that allows you to move whatever you are coating in one end and out the other.

A DOUBLE-CROSSFLOW powder spray booth is also tunnel-style booth. It is similar to a crossflow configuration, but has an exhaust system mounted on each side wall. One benefit of this design is that it allows the painter to stay clean and work quickly. He can move the rack slightly and always be painting into the exhaust filters—as opposed to spraying powder onto the part while the exhaust is behind him, causing the overspray to cover him as it is pulled out of the booth by the fan. A double-crossflow booth also allows two painters to work effectively at the same time, especially when the exhaust units are mounted in a diametrically-opposing position. In that configuration, each painter deals with only one part of a large part or rack full of parts and is always spraying into the exhaust filters. As the rack moves through the booth, each painter sprays only a designated portion of the parts being coated.

In nearly all types of automated systems, a tunnel-style powder spray booth is paired with a tunnel-style powder coating oven with track running through both appliances so a continual coating process can be maintained. In a batch setting, the booth configuration should help improve coating workflow and maximize use of available floor space.

Plan For Staging Areas Around Your Coating Equipment

racks-for-powder-coatingAnother thing to consider when planning for your powder spray booth (and your coating line in general) is staging. A staging area refers to the additional shop space you’ll need for storing racks and parts as they move through the pretreatment, coating and curing processes. Even if racks are only going to be parked in a spot for a few minutes, it is important that the spot is clearly defined and kept clean.

Make sure you have a staging area where the parts can be prepared before they enter the powder spray booth. Whether you use blasting, chemical pretreatment, or simply a wipe-down before the parts are coated, you need to be able to stage parts after they’ve been prepped. This staging area is where your racks will be loaded with clean products, and may be where empty racks are returned. This staging area needs to be large enough to accommodate at least one typical batch of products.

In some batch operations, a second staging area is placed between the powder spray booth and the curing oven. In most batch operations, the powdered parts go directly into the curing oven. But, if your coating throughput is very high or you’re curing something that requires a long dwell-time, you may need this second area to store your previously coated parts away from shop traffic before they are placed in the curing oven.

IMPORTANT: Don’t let your powder coated parts wait too long before curing. Powder does not immediately fall off once a part has been coated. Good adhesion isn’t hard to achieve as long as you have a proper ground during application. Typically, uncured powder coating will adhere to the part for several hours with no ill effects. However, the longer you leave the powder uncured, the more exposure it has to moisture, handling damage, dust and airborne contaminants that cause imperfections in the cured finish.

Once you remove the cured objects from the oven, the racks and parts must have a place to cool before being handled. This final staging area is where the parts can adequately cool before assembly or packing. It’s very important to stage cured parts away from pretreatment areas and powder spraying operations to prevent accidental contamination of the powder finish before it has cooled and fully hardened.

A Custom Solution For Your Exact Needs

Reliant Finishing Systems manufactures over 250 standard powder spray booths, as well as fully custom booths built to client specifications. Our booth configurations are also available with matching powder curing ovens, wash stations, dry-off ovens and blast rooms. Our modular, perfectly-matched appliances are easily configured for a fully integrated powder coating line. Regardless of your finishing equipment needs–from a small batch oven or booth to a complex automated powder coating line–the specialists at Reliant Finishing Systems can help you determine exactly what equipment you need to get the best results. Let us provide you with a list of some of our very happy customers. We’ve worked with hundreds of unique layouts and design requirements, and our technicians have installed countless coating systems across the U.S.A. and abroad. When you’re ready for a new booth, oven or complete powder coating system, give us a call!

Five Things You Should Never Do With Your Batch Powder Coating Oven

Whether yoBatch Powder Curing Oven Control Panelu’ve just started coating or have been operating a batch powder coating system for years, you know that the coating oven is an expensive appliance and a vital part of your coating operation. Keeping your batch oven in good working order is critical to long-term success. A well-maintained powder coating oven can last for over a decade, produce thousands of high-quality parts for your customers and be a considerable source of income for your business.

However, a batch oven that is operated incorrectly can be a serious safety hazard that’s unreliable and can cause you nothing but problems and headaches. To help you avoid making a costly – and potentially dangerous – mistake, here are five things you should NEVER do when operating a powder coating oven.

1) Don’t Run The Oven Above The Recommended Temperature

Most batch powder coating ovens are rated for sustained operation at temperatures of up to 450° F, while some more expensive models are rated up to 500° F or higher. If you own a conventional 450° batch oven, jumping up from 380° to 480° in an attempt to save a few minutes of cure time will harm the equipment, possibly trip the safety devices (leading to downtime) and potentially damage the finish on your parts. Every powder is rated for a specific temperature range. Going above this range will make the finish brittle and less durable, and can cause discoloration issues. This is especially true with glossy white finishes. Also, the few extra minutes you might save aren’t worth voiding your warranty or damaging costly components, especially on a critical piece of equipment like a batch curing oven.

2) Don’t Reduce The Exhaust Airflow In An Attempt To Save On Heating Costs

All professional-grade gas fueled ovens are built to exhaust a certain amount of air whenever the oven is in operation. The exhaust causes the air to move in a particular pattern within the oven cabin, keeping the cabin a stable temperature throughout. If you reduce or eliminate the exhaust airflow, you can create hot and cold spots that weren’t there before. These temperature changes will cause the powder to overbake or underbake, resulting in poor finishes and lots of reworks.

You’ll also have problems with safety devices. If you disable the safeties to keep them from tripping, you are violating important safety codes and you’ll void your warranty, no matter who built your oven. Another problem is that if there isn’t enough air being exhausted from the oven, you can have significant heat loss at the doors or oven panel seams. You may also have problems getting the doors to latch properly.

3) Don’t Overload The Oven Trying To Increase Throughput

If too many objects and racks are added to the oven, there’s a high probability you will accidentally block the oven exhaust or airflow ducts inside the cabin. If the exhaust is blocked, it adds stress to the exhaust fan and can shorten the service life of both the fan and the drive motor. It can also promote hot spots inside the oven that can damage parts, rolling racks or the oven cabin itself. If the supply ducts from the heater are obstructed, the powder can get blown off the parts. A bigger problem arises if the airflow through the heat unit gets reduced. This not only kills fuel efficiency but it also causes the temperature inside the heat unit to skyrocket. This can result in the heat unit’s fan failing, reduced service life from the motor, erratic operation due to safety circuits being tripped and even structural damage to the heat unit.

4) Don’t Skip Maintenance

Remove-BoltNo matter how busy the coating line is, skipping scheduled maintenance will shorten the service life of important oven components and can lead to critical failures. The majority of service calls we receive regarding older ovens are linked to poor maintenance practices. Most of these calls come from successful powder coating shops that use their equipment daily and stay busy–but they learn the hard way that “we’ve been busy” is no excuse for avoiding routine maintenance procedures. Keep your oven clean. Service the burner regularly. Lubricate bearings as directed. Check ductwork for obstructions. Don’t let a nuisance issue, like a noisy exhaust fan or a worn-out door latch, result in costly downtime because you were too busy to deal with it when you first noticed it.

5) Don’t Install The Oven Too Close To Other Equipment Just To Save Shop Space

Batch Powder Coating Oven Maintenance Walkway

Make sure to allow for enough space around your coating oven to meet safety codes and allow for easy maintenance access.

From time to time we encounter a situation where a customer has installed his oven too close to his powder booth, his welding operation, a clean-up station, his blasting operation or some type of chemical pretreatment wash station. Not only does this violate safety codes, but debris, fumes or even powder from other appliances can cause problems with your oven or your finishes.

We were recently asked to troubleshoot problems with a high-end oven from another manufacturer. We discovered that the oven worked fine, but the parts were being exposed to WD-40 fumes during both the coating and cool-down stages—resulting in unacceptable finishes. Although this wasn’t damaging to the oven, similar exposure to airborne grit from blasting or pretreatment chemistry from a washer could have been.

Another common problem is when the “guts” of a powder coating oven get coated with a layer of powder over and over again during operation because of powder overspray from a nearby booth (usually one that needs a filter service). The burner safeties can cause the oven to shut down, the fan can come out of balance due to an uneven layer of melted powder and ductwork can become restricted. All of this can be prevented with proper planning and equipment placement.

Routine Maintenance and Scheduled Service Can Keep You In Operation For Years To Come

At Reliant Finishing Systems, we pride ourselves on providing some of the best and most efficient batch coating equipment on the market. By following these tips, making sure you’re following a set maintenance schedule and contacting us for service visits when you have problems, you can help increase the lifespan of your equipment and maximize your ROI.

Have any questions about powder coating equipment or need to schedule a service visit? Give us a call today.

Improving The Performance Of Your Batch Powder Curing Oven

Batch Powder Curing Oven From Reliant Finishing Systems If you use a walk-in sized batch powder curing oven for your powder coating operation, you may have questions about how to consistently get the best results from your equipment. The oven’s performance–particularly the air temperature and airflow inside the oven–can make or break the quality of your finished products.

These important tips can help you get the best finish possible from your curing oven:

Make Sure The Oven Is Sized Correctly For The Project

Powder coating ovens can be built to nearly any height, width or depth. The ideal size for your project is dependent upon what you are going to be coating. No matter what you want to coat, the entire object needs to fit inside the oven with room to spare. For more information on oven sizing guidelines, click here.

Keep Parts Away From Walls, Doors, Ductwork And Ceiling

Powder Coating Oven VentsDepending on which brand of oven you have, heated air is usually blown into the oven via ducts in the ceiling or wall, or sometimes both. When curing, make sure you have enough space between the ductwork and the parts. If the parts get too close to the ducts, the powder can get blown off and you will have to rework the part.

Likewise, if a part touches the oven’s interior, the powder is likely to either rub off completely or flake away during curing. In order to get a proper finish, the parts can’t touch the ceiling, ductwork or walls, and they can’t impede the operation of the doors or rub against them.

Also consider how the parts will be carried in and out of the batch powder curing oven. Most parts are hung on rolling racks (also called parts carts), so there has to be enough room for the rack to fit into the oven once the parts have been hung. If your rack bumps into the walls of the oven, the powder you applied can get knocked off.

Keep Parts Off The Ground

Just like you will need to allow for room near the walls, ceiling, doors and ductwork, you also need to avoid hanging parts so that they nearly drag the ground. If possible, the lowest part of the biggest parts should be 10” or more off the floor. This makes the temperature of the parts more uniform and allows the powder to cure more evenly. It also helps prevent dust contamination if the oven’s heat system blows dust and dirt from the floor onto the parts.

Routinely Check Your Batch Powder Curing Oven’s Temperature

Some ovens have better temperature uniformity than others, but none are perfectly uniform. Ovens with ceiling ducts are usually cooler at the floor than elsewhere. Ovens with wall ducts may be cooler in the corners, and possibly near the floor. It is recommended that you routinely check your oven’s temperature with an oven data recorder (a Datapaq or similar) and keep a log of the results. Get professional help fine tuning your oven and adjust your curing practices as needed.

Check Your Shop For Airflow Issues

Batch Powder Curing Oven - Doors OpenAlthough it might not be obvious, drafts and air currents in the shop influence the way an oven operates. Some days there may be giant wall-mounted vent fans in operation to help keep the shop cool or get rid of welding fumes. Other days there may be one or more heaters in operation to keep office or shop space warm. Many shops have roll-up doors that are constantly being opened and closed. Wind can blow into the building or move across openings and create an imperceptible vacuum or pressurize a shop in ways that can easily overcome a powerful fan system. All of these things can impact your oven’s performance.

If you notice a change in your oven’s performance, check for changes in the way air moves through your building. Is air blowing in from outside that wasn’t a few days ago? Were the building exhaust fans turned off but the vents left open? Have you started using an AC system or have you cranked up heaters that weren’t in use until recently? Does the oven only have problems when a roll-up door is opened or closed? Examining the airflow within the shop can often help you pinpoint oven operation issues.

Check Your Fuel Source When Local Usage Changes

Another factor that can make a huge difference in the way an oven runs is fuel supply. Whether your oven is burning LP or natural gas, changes in the fuel supply can cause problems that are almost impossible to trace. These issues can be due to weather changes, new construction near your shop, changes within your building, or changes to your style of use.

If an oven is calibrated during the summer, the gas supply may decrease during the winter because of increased demand. This may be due to your neighbors (especially if located near a hospital, apartments or a large office complex) or may be because you’re using more fuel to run heaters or gas-fueled appliances within your own building that are tied in to the same line feeding your batch powder curing oven.

A similar problem can occur if new apartments or other types of high-demand buildings are constructed near your building. Once occupied, they may cause changes to the fuel supply coming into your building. Along the same lines, if you add shop heaters, steam units, or additional ovens, it may reduce the amount of available LP or natural gas fuel.

Remember, gas pressure and gas volume are not the same thing. It is possible to have a situation where the pressure gauge shows plenty of pressure when the oven is at idle or turned off, but then have performance issues once the oven goes to high fire. This usually happens when the supply line or regulator is too small. The oven can also have problems if the supply has enough volume, but the pressure is too high (dangerous and can cause the safeties to trip) or too low (can cause the oven to fail to ignite or to take too long to get to curing temperature). For best results, the oven needs an adequate volume of gas delivered at just the right pressure.

Always Follow Safety Procedures

IMPORTANT: If your shop’s work schedule becomes busier or you change operators, it is possible to have oven issues crop up because of the way the oven is being used. One common problem is caused by operators opening the oven doors for loading/unloading while the oven is running. This is unsafe and can lead to property damage, serious injury or death. It also causes the heat system to burn a large amount of fuel as it tries to maintain curing temperature while heat is rapidly escaping from the oven through the open doors. Not only does this waste fuel, it can reduce the service life of expensive oven components because of the burner’s extremely high output. When you’re ready to open the oven doors, shut down the burner but leave the fans running. Turning off the fans while the oven is at curing temperature can cause them to warp or can cause related parts to fail prematurely.

Follow Factory Maintenance Recommendations And Usage Guidelines

Batch Powder Curing Oven Control PanelEvery powder coating oven manufacturer provides a maintenance schedule which outlines the safest and most effective ways to operate their equipment. These factory-recommended “best practices” describe the style of use that is safest, most efficient in terms of manpower, least expensive in terms of fuel use, least likely to result in down-time due to equipment repair, and most likely to prevent unusable powder coated parts that are rejected due to poor finish quality.

There’s a reason why successful shops that are noted for premium quality work or incredibly high throughput keep their equipment in top shape and operate it properly. Having a set schedule for cleaning, maintenance and lubrication of your batch powder curing oven and related equipment will help you get consistent, high-quality finishes. Similarly, only running the oven within recommended temperature ranges is not only more fuel-efficient, it is safer for your operators and less likely to damage parts. Oven providers typically offer strict guidelines designed to assure that you get the best results from your equipment and the highest level of efficiency. Following those guidelines will help save you from expensive equipment repairs and costly parts reworks due to bad finishes.

Need An Equipment Check-up?

Reliant Finishing Systems batch powder curing ovens are always set up by our factory-authorized technicians to provide performance that is well balanced. We want our ovens to reach operating temperature quickly, while burning as little fuel as possible, and we are committed to helping shop owners keep our equipment in the best operating condition possible.

If you have any service or maintenance issues, please give us a call today. Scheduling a visit from one of our factory-authorized technicians can help solve curing issues, improve your efficiency and increase the lifespan of your equipment. Available services include troubleshooting, Datapaq recording and line audits, preventative maintenance, and both routine and emergency repairs. Call today for more information or to schedule an appointment.

Getting the Right Blast Room For Your Operation

Blast Room Operator Cleaning Part For Powder Coating

Blast Room Operator Cleaning A Part For Powder Coating

There are a number of factors to consider when adding a blast room or abrasive blasting system to your powder coating or painting operation. No matter what type of dry blasting system you are considering, this guide is designed to help answer your questions and plan for your success.

Note: Although uncommon, wet blasting systems, also known as slurry blasting systems, are sometimes used. This article focuses on dry blasting systems, particularly those designed for manual blasting by one or more operators inside a walk-in size steel enclosure.

Part 1: The Blasting Enclosure

Before deciding on a blast room, it’s best to familiarize yourself with some of the features common across most manufacturers. Almost all blast rooms feature a square roof design instead of hip-style roofs. The square roof construction allows for more operator movement, easier load-in and load-out, and has better lighting. Light gauge hip roof models – which are often the cheapest on the market – may not provide the durability and usability you are looking for.

Wall and roof panels are usually available in thicknesses that range from 18 to 10 gauge or thicker. As a general rule, the heavier the wall thickness, the higher the cost. Everyone wants a heavy duty blast room, but heavier construction often offers no real benefit because high-wear areas are typically covered by rubberized shielding.

Blast rooms are commonly equipped with a moderate number of multi-tube fluorescent light fixtures and feature safety glass in order to meet code.

Upgrades To The Blasting Enclosure

While there isn’t much to upgrade when it comes to the cabin of conventional blast rooms, the door design is one area of the cabin’s construction where upgrades are typically worth the cost. The majority of professional-grade blast rooms include conventional swinging doors with louvered openings. Premium models may feature perforated doors with adjustable splash shields to keep spent media inside the blast room while allowing fresh air to be drawn into the enclosure. Ruggedized fabric or rubber roll up doors can be requested at an additional cost. They help reduce the amount of shop space required.

A typical blast room ships with one full-width, full-height door set, and may have one or more separate personnel doors. Some manufacturers offer a curtain wall or curtain door option to reduce cost, but these configurations are not popular with most shop owners because they don’t provide as much containment as other designs.

Get The Right Size

Make sure the blast room is the right size. Many of the considerations we outlined in our powder coating oven size guide will be applicable here, but make sure you give your parts and your operator plenty of room. For example, if the parts you need to blast are very tall, consider adding some additional height to the cabin so you won’t constantly be blasting into your light fixtures or the unprotected ceiling surface. Also, if the part you want to blast takes up the majority of the cabin, give your operator extra width and length to safely work around the part without standing in a stream of blasting media bouncing back towards him. Check out the ovens at

Part 2: Blast Pot

The blast pot (also referred to as a blasting pot, pressure pot, pressure vessel, media blaster or portable blaster) is the appliance that does the actual blasting. There are a number of blast pots on the market, but all of them work essentially the same way. A blast pot is a pressurized container with a hose and spray nozzle attached. Abrasive media is loaded into the blast pot and sealed air-tight. Once sealed, the media is pressurized using compressed air. A valve at the end of the hose is controlled by the operator. When the valve is opened, compressed air forces the media to travel down the hose and spray out the nozzle.

Four factors affect the price of a blast pot: capacity, portability, construction quality and configuration.

Capacity: Typical blast pots hold 4 to 7 cubic feet of blast media per loading. As an example, the 650 XL model we offer with our Reliant Finishing Systems blast rooms has a 6.5 cubic foot capacity. As a general rule, the smaller the capacity the cheaper the unit, but reduced capacity will increase downtime for reloading.

Portability: The least expensive blast pot models come mounted to a skid or have attachment points so that they can be permanently mounted inside the blast room. Portable units, with wheels mounted to the base of the blast pot, are usually a bit more expensive.

Construction Quality: All blast pots offered by brand-name manufacturers are safe and well made. There are, however, small differences that can drive the price up, but may be well worth the expense. This is particularly true when dealing with premium hose fittings, roomy clean-out openings and more robust sealing systems. Even a simple feature like an adjustable stand versus a fixed one can improve convenience and increase throughput.

Configuration: Almost all common blast pots have one hose and nozzle for use by a single operator, but more expensive multiple operator configurations can be provided by some suppliers.

Other Factors To Consider When Purchasing A Blast Pot

Make sure the blast hose is of the same diameter and length. Find out if each blaster has a safety system to assure that the blasting operation stops instantly if the hose is dropped and the valve at the nozzle released. Determine the orifice size and construction material of each unit’s spray nozzles. Remember, the orifice is sized depending on the media you want to spray and the maximum output of your compressed air system. A larger nozzle takes more air and uses more media, but strips metal at a faster rate.

Part 3: Dust Abatement

When considering options for your blast room, it is very important to remember the difference between dust abatement and media reclamation.

Media reclamation refers to a system that allows you to collect and reuse the blast media (such as steel shot).

Dust abatement, on the other hand, refers to the fans and filters that remove the dust from inside the cabin while the blast room is being used. These fans and filters are separate from the reclaim system and are only used to reduce airborne particulate inside the blasting cabin.

Why is that important? A blast room produces a lot of dust. You are blasting old paint, rust and grime off your parts to get them ready to powder coat or paint. Without proper dust abatement, your operator will be working in a dust cloud that will render him unable to see what he is doing.

The media reclamation system does not move enough air to effectively remove airborne particulate from the enclosure. So, an operator using a typical reclaim unit won’t be able to see what he’s blasting unless the blast room also has a second system designed to filter the air inside the room.

Remember that dust abatement does not remove spent media or heavy debris from the blast room. Dust abatement systems (sometimes called dust collection, dust containment or dust control systems) ONLY affect the airborne dust inside the cabin.

Entry-level blast room models may not come with built-in dust abatement or they may feature a dust abatement system that uses disposable air filters. These simple systems draw fresh air into the room and route exhausted air through a series of filters to ensure that only clean air is returned to the facility. The filters are protected by steel baffles so they are not damaged during blasting, but they must be changed frequently during periods of heavy use. These filtration systems remove enough airborne particles to allow the operator to see what he is doing and to keep the air inside the booth relatively clean.

The most popular dust abatement systems use cartridge type filters. The filters are much longer lasting and can be set up to automatically self-clean using compressed air. These abatement systems usually have a large waste bin located under the filters, and the collected dust and debris falls from the filters into the bin during cleaning, so they may also be considered dust containment systems. The collected dust and debris is usually removed manually by the operator, but upgraded models exist which include a pump that transfers the dust and debris out of the collection area.

More expensive cyclonic dust removal systems are available, but for most buyers the cartridge filtration option offers the best mix of affordability and performance. Both cartridge and cyclonic systems provide excellent dust abatement and allow operators to see clearly inside the blast room, even though some amount of airborne particulate inevitably ends up settling on the floor of the enclosure.

Part 4:  Choosing the Right Media Reclamation System

A powder coating shop can increase throughput, reduce blasting costs and assure code compliance by bringing their blasting operation indoors. They can further improve profitability by using recyclable abrasive media. To make the most of recyclable abrasives, an efficient recovery system is needed.

A media reclaim system usually has a low-volume/high-pressure intake that moves spent media, debris and dust out of the blast room. (As we said before, that does not make it a replacement for a good dust abatement system because the volume of air being exhausted is not enough to clear the air.)

It is not uncommon to see a blast room with dust abatement but no recovery system for spent blast media. Although recovery systems speed throughput even if the blasting media cannot be reused, most shops that use disposal blasting grit don’t use any type of recovery system.

Media Reclamation/Pneumatic Recovery Systems

Blast Room With Pneumatic Recovery System From Reliant Finishing SystemsMost sweep-in media recovery systems, which are often provided in addition to dust abatement equipment, offer an economical alternative to full-area media and waste recovery. A sweep-in system can be installed inside a new or existing blast enclosure. This will increase throughput and allow you to switch to recyclable abrasives. In a high-production environment, the cost savings and increased productivity can pay for the recovery system within months.

Conventional sweep-in media reclamation systems are pneumatic. These recovery systems efficiently remove most low to medium-density blast media, such as sand, glass beads, plastic, nut hulls and aluminum oxide. The recovered media, if reusable, can be recycled. A pick-up bin or trough can be mounted in a shallow pit in the floor for a true sweep-in operation, but is often surface mounted when the owner wants to be able to move the pick-up bin (or when the situation will not allow excavation of the shop floor). Some shops that use non-recyclable blast media still choose to install a pneumatic recovery system in order to increase throughput and prevent operators from spending time shoveling spent media into trash bins to be hauled away. They use the pneumatic system to transport the waste into large trash hoppers that can be emptied less frequently. With many pneumatic systems, debris is sorted from spent media via a classifier that relies on cyclonic airflow–debris is routed into trash hoppers and recovered media is returned to the blast pot’s feed system.

Media Reclamation/Auger (Screw-Type Conveyor) Recovery Systems

Auger systems are designed primarily for use with heavy, durable media like steel shot. These screw conveyor systems can be linked to a pneumatic recovery system when using lighter blasting media. For steel shot, a reclaim module mated to a bucket elevator can continuously process up to almost 200 cubic feet of media per hour. Augers are commonly available in lengths of 8’ to 20’, and can be provided in lengths of 50’ or more by special order. Most augers feature 6” helical flights. It is common for these systems to have integrated metering plates to prevent over-loading. Since they are used most often with steel grit and shot, most screw-type conveyors are mounted in an excavated pit so that the heavy-weight media can be pushed into them using a skid loader or easily shoveled in by hand.

Media Reclamation/Hopper & Bucket Elevator Recovery Systems

A hopper and bucket elevator recovery system serves as something of a hybrid between an auger type system and a pneumatic system. Since the pneumatic systems cannot transport heavy blast media, an elevator is required. The hopper and elevator system requires the operators to move the material into a recovery bin (just like pneumatic sweep-in systems). With diligent operator support, you can process up to about 180 cubic feet per hour of dense media, such as steel grit and shot. Typically, a small reclaim bin or hopper is mounted flush with the shop floor inside the blast enclosure and the operators use shovels or brooms to push spent media into it. When a flush-mounted hopper cannot be used, a smaller stand-alone or wall-mounted bin can be used and loaded by the operators using shovels.

Media Reclamation/Belt Conveyor Recovery Systems

Belt conveyor recovery systems are expensive, but use fairly simple technology to automate the recycling process. A typical complete belt conveyor system includes recovery bins, floor grating, a series of motor-driven belts, a bucket elevator, and an abrasive cleaner (such as an air wash system). When someone talks about a “full floor” or “full area” recovery system, they are usually talking about a belt conveyor system. There are also many versions that have collection built into only part of the blast room’s floor.

Belt conveyor systems include one or more collection bins installed in a recess in the blast room’s floor. Partial-area collection systems can be configured in a single linear run or in “H,” “L” or “U-shaped” patterns as required for the particular application. Reinforced floor grates, mounted flush with the blast room floor, cover the collection bins. Spent blast media falls through the grating and into the hoppers and travels through a metering tube before falling onto one or more conveyor belts below. A separate motor drives each belt, and conveys spent media and debris to a bucket elevator for transfer to the abrasive cleaner.  As with auger or hopper systems, spent blast media is returned to a recovery bin. Specially designed buckets transport the abrasive blast media from the bin to a cleaner, where the abrasive material is separated from dust and debris. Debris falls into a waste container, dust is drawn into a separate dust collector, and reusable abrasive media falls into a hopper used to feed the blast pot.

Part 5: Safety Gear

Don’t skimp on safety. Professional quality safety gear can actually help operators be more productive, so it pays for itself fairly quickly. A good safety package starts at around $1,000. It usually includes protective wear, a helmet and respirator, and a good air filter system. Although it looks cumbersome, once an operator adapts to using this type of gear he is almost always working faster because he doesn’t have as many safety concerns and he can see what he is doing while working near the surface he is cleaning. This is especially true when dealing with detail work that requires a close-up view.

Not only can safety gear increase throughput, it helps reduce liability and prevent injuries to your employees. Safety gear is a win/win for your shop and employees and it’s an option we strongly recommend.

Part 6: Professional Installation

Some very expensive small and mid-size blast rooms arrive at your site ready to install. You connect the blasting and exhaust components, then add power and air. Because these pre-built rooms must ship via truck, these blast rooms’ interior dimensions are limited to heights and widths of less than 8’. Other than these models, there are a few DIY kits on the market, including affordable blast room kits manufactured by Reliant Finishing Systems.

For the vast majority of the blast rooms on the market, installation by factory-authorized technicians is required. In all cases it is recommended! The cost of installation labor is either built into the equipment price or listed as an add-on service. Whether you buy a small blasting room for occasional use or a giant blasting enclosure for non-stop blasting, professional installation helps assure that your equipment will operate safely and effectively.

Part 7: Material Handling

Once you start blasting, you’ll be faced with the need to safely support parts while a powerful stream of abrasive material is directed towards them. If your current racking and handling system has problems transporting parts from your powder coating booth to your oven, it probably won’t be secure enough to keep parts in place while they are being blasted.

You can develop a better way to secure parts through the entire prep and coating process, but many coaters go to a manual or semi-automatic system where parts are dealt with during blasting (and chemical pretreatment if used) and then transferred to a different hanging system for coating and curing.

Any Questions?

No matter what type of blast or pretreatment system you are considering, the experts at Reliant Finishing Systems can answer your questions and provide the equipment you need to get the perfect finish every time. Give us a call today.

Buying New vs Used Powder Coating Equipment

used powder coating equipment

When you purchase used powder coating equipment, there’s no guarantee you’ll get what you need.

For many businesses, investing in capital equipment is the largest purchase decision they are likely to make. It is not surprising that many business owners, coating line managers and purchasing agents look to reduce their businesses’ expenses by purchasing used or salvaged equipment. This can sometimes appear to be a very effective way to save money – however, the reality of new vs used powder coating equipment, the potential problems often far outweigh the anticipated cost savings.

It’s true that buying smaller, less complex tools, such as a saw or welder, from a used equipment dealer or directly from the previous owner may save you money. Unfortunately, that’s rarely the case with more complex machinery. Powder coating booths and ovens are prime examples of equipment that is almost never a good value to buy used, no matter how low the price.

A powder coating system should be matched to your specific requirements, but the likelihood of you finding exactly what you need in a used system is very slim. By the time you have modified, upgraded, refitted and refurbished a used or salvaged coating system, you will have often spent as much – if not far more – than if you had invested in a properly sized new system from the start.

Avoid The Hidden Expenses Of Buying Used Powder Coating Equipment

For this article, we reached out to a few of our clients (some purchased new equipment from Reliant Finishing Systems instead of buying used, and some first bought a used system before investing in a new Reliant system). We asked them to tell us about their experiences while shopping for their coating systems. Our goal was to find out what challenges a used powder coating system can present to a new coating operation. The feedback we received was overwhelming; if you’re considering buying used equipment, don’t do it!

Here’s some of the biggest headaches that buyers encountered:

No Factory Warranty On Used Powder Coating Equipment

Very few used ovens or powder booths have a warranty for their parts. Your oven is the heart of your coating operation, so any downtime can kill you. If the oven goes down, you will be completely unable to cure your parts. Along the same lines, a motor failure or damaged/clogged filters in your booth can leave your coating line at a standstill. Without a warranty on hard-to-source parts like specialized bearings, fans, and burner components, repairs due to mechanical failure are potentially very expensive and time-consuming.

Another issue is that used powder coating equipment has often been modified by previous owners. Figuring out exactly what parts are actually being used can be an added hassle and one you’ll have to navigate by yourself. Contacting the original manufacturer of the equipment will often get you nowhere. These companies are worried about liability, especially if the used system was heavily modified or improperly disassembled / installed. Without any factory technicians there to verify the condition of the equipment, most manufacturers won’t help you if you have a used system. If your equipment has a critical parts failure, you’ll be stuck on your own.

No Factory Support

Hand-in-hand with the lack of warranty, used equipment is often sold without any sort of support from the original manufacturer. In fact, many oven manufacturers from the 1980s and 1990s are out of business. A few from the last ten or so years have also folded, so there is a chance you may buy an appliance that looks good but is totally unsupported. This can be a huge problem down the road if any wear parts are proprietary in nature. It can also be problematic for day-to-day operations, as there are fewer and fewer trained technicians still familiar with the minor problems that may arise with products from suppliers that are no longer in business.

Used Powder Coating Equipment May Not Work Like It Should

When buying used powder coating equipment and basing your decision on price alone, it can be tempting to purchase equipment that is similar to what you need, even though you know it is not an exact match to your requirements. This can be a costly and hazardous mistake.

For example, buying a salvaged gas-fired oven that was used for curing ceramics or heat treating metal may seem like a great idea because the price is $10,000 lower than buying a new batch oven designed specifically for powder coating. In the long run, the oven may not be effective for your powder coating operation. Why? Because buying an oven with a recommended temperature range higher than a powder coating oven may result in over-cured parts and wasted money due to reworks. Trying to run a lower-temperature oven at powder coating temperatures can be extremely dangerous, especially if you are running the oven outside the recommended safety range by bypassing safety devices. In all cases, buying an oven that hasn’t been optimized for powder curing will result in fuel bills that are much higher than they should be.

Buying the wrong oven for the job will cost you money in fuel and can cause powder overbake, damage the parts themselves, or be a fire hazard. There’s also the possibility that your code inspector will simply “red tag” your appliance and you’ll be unable to use it.

Incorrect Power Can Cause Expense & Delays

A low price on used powder coating equipment may not make up for the potential expense of hundreds or thousands of dollars spent for rewiring and replacing controls. Capital finishing equipment is typically designed for each specific customer, and that includes correct wiring for that customer’s location and power source. If you buy used, you may find your equipment wired for single or three phase when you need the opposite. You may also end up with equipment designed for a voltage that is not compatible with your current power source. These differences can lead to significant rewiring and the need for a new or heavily modified control panel. Obviously, this will add to the cost significantly.

We’ve encountered shop owners who bought used or salvaged equipment at auction and the power was designated only as “high voltage” or “3-phase.” They later learned that they had to choose between spending tens of thousands of dollars on a new incoming power supply to their coating equipment or dealing with the cost and delay of reworking the equipment so it was compatible with the power they had.

Safety Issues May Turn Used Powder Coating Equipment Into A Hazardous Money Pit

Older equipment, especially ovens, will often have different and potentially outdated safety features than current models. If those older safety features cause code compliance issues with local inspectors, you will have problems that can take months to resolve. Imagine being shut down for two or three months after you get your equipment assembled because a flame safeguard in your oven’s control panel or a fire detection photo eye in your used high-end booth doesn’t work properly.

Updating the oven or booth to meet code requirements can be costly. Choosing not to update can incur possible fines or your local Authority Having Jurisdiction may simply lock you out of your equipment. If this happens, it will be illegal for you to operate your coating equipment until it has been upgraded to meet certain performance or safety specifications. Even if no inspector is involved, the safety features of used powder coating equipment need to be checked and replaced if they no longer operate properly, as bypassed or outdated safety features can pose a serious safety risk to you and your employees.

Missing Parts Cause Expensive Delays Or Make Used Coating Systems Inoperable

Many used systems have been salvaged. More expensive ones are usually shown under power and then torn down and packaged for shipment. Some used coating systems are missing key components, but it is hard for the buyer to know exactly what has been left out until the equipment is being installed at his facility.

It isn’t uncommon to see used powder coating equipment outlets offering systems made from two (or more) salvaged appliances from totally different coating lines. These products are packaged together in order to make one complete system. Without knowing precisely what is missing and what has been replaced on the system, it is almost impossible to determine if a used powder coating system has all of the capabilities it was designed to offer.

Two of the most expensive items to replace on a powder coating oven, the gas burner and the control panel, are the most likely to be absent, damaged, modified by previous owners, or just plain worn out. Replacing those two items alone can increase the price of an “inexpensive used system” by $10,000 or more before it can be used at a new location.

Salvaged powder spray booths often lack useable filters. A complete filter set for a well-made cartridge filter system can easily cost over $1,000. A set of HEPA filters for a booth with a spray-to-waste filter system can cost almost as much. There’s also the cost of replacing old mismatched bulbs with new ones, replacing broken glass in light fixtures (required by code), and making sure the exhaust system has all of the motor and belt guards in place.

Without the correct replacement parts, a bargain priced (but incomplete) used coating appliance can leave the new owner in a bad situation.

Older Guns & Powder Reclaim Systems May Have Parts You Can’t Replace

Depending on the brand and the specific model, some powder guns that have been discontinued for only a few years may be all but worthless. These guns and their related reclaim/powder transfer systems may no longer have available replacement parts. Once they wear out, the only way to get replacements is to track down other used systems to salvage. What’s worse, if you aren’t dealing with one of the larger powder gun companies (Gema, Nordson and Wagner), used gun systems similar to the one you are buying may not have compatible parts, even though the gun model is identical. This is especially true of guns that are designed to look like brand name guns but have been manufactured in Asia or assembled in hobby shops in the U.S. using foreign parts. These low-end guns are commonly sold via the Internet, and we’ve seen products where key components have been changed multiple times within only a few months without any change to the model designation.

Structural Modifications May Be Required After Reassembly

Ovens expand and contract during operation. This can cause warping of the panels or weakening of structural components. Depending on how often, and in what manner the used oven was operated, the panels may not fit correctly after disassembly. Once relieved of the pressure created by fasteners and adjacent components, panels may deform. Any unusable panels will either have to be purchased from the original equipment manufacturer or provided through a custom fabricator. Additional bolts, self-tapping screws and/or sealant will also have to be used in order to prevent hot air from leaking through improperly fitting wall or roof panels.

On many popular batch ovens, the doors are permanently fixed to a door frame assembly. Often these doors have been custom fitted in the field so that the doors operate properly even if the floor at the installation site is imperfect. During reassembly, it is common for the door components on a used powder coating oven to require modification in order to work with the floor imperfections found at the new installation location. This can be another costly and time-consuming modification that will often require communication with the original manufacturer.

Interior Rust May Be Undetectable Until It Is Too Late

If an oven has been installed or stored in a humid environment, the insulation can trap moisture against the interior of the wall panels. Although their construction is designed to deter rust, the panels of a used oven can be rusting from the inside out and the rusted panels will have to be repaired or replaced. Without tearing the panels apart, it is impossible to know if rust is going to be an issue. The oven may look fine, but a rust problem may not be apparent until it is too late to avoid costly panel repairs or outright replacement. The more an oven has been moved or disassembled/reassembled, the more likely it is that rust may be a concern.

Insulation Doesn’t Always Travel or Age Well

Most ovens feature 4” or more of mineral wool insulation. Reliant Finishing Systems is somewhat unique because our ovens feature 6” panels that can be completely broken down. This allows the buyer to be confident that each and every panel has been properly insulated. What we’ve learned from working with dozens of tons of mineral wool every year is that it often settles inside an oven’s panels—especially if exposed to a moist climate. We’ve taken apart a handful of panels from used ovens that were installed when new, then disassembled and sold a few years later as “like new.” The rigors of being shipped thousands of miles, then having the panels slammed together during assembly and snatched apart during tear-down caused the mineral wool inside to break down slightly. After a few years of use, the insulation began to settle. As a result, the “good as new” used oven’s wall panels had no insulation at the top of the panel. Another thing we noted was that after being subjected to high temperatures for a few years, the insulation became somewhat brittle. Instead of a stiff board of insulation inside, the panels had insulation that no longer evenly covered the entirety of the panel. This lack of fresh mineral wool throughout the entire oven construction leads to heat loss and safety issues. Even with our own ovens, a certain amount of insulation will need to be replaced if a Reliant oven is going to be moved and reassembled.

Installation Labor Is The Biggest Gamble

When you buy new equipment, the manufacturer or the equipment dealer typically offers installation services. These services are provided at a set price and include calibration of the equipment. Factory-installed equipment should look good, perform well, and be safe and reliable. When you buy used powder coating equipment, one of the biggest hidden costs is the likelihood of the installation bill being significantly higher than originally expected.

When buying equipment that is “as is, where is” at a low price, it is easy to forget about the cost of having the equipment torn down and packaged for transport. As an example, let’s consider a large batch oven and powder spray booth package that includes some structural steel supports. Let’s say that if the equipment is bought used it will save you $25,000 over buying new. Let’s estimate that the cost for having new equipment installed is going to be $15,000. It is reasonable to expect to pay more to have the used equipment built because technicians charge more to offset the delays that they anticipate with used equipment, so $20,000 is a solid estimate. Then you have to pay to have the equipment removed from the original site, which might cost $7,500, plus you’ll spend maybe another $2,500 to have the equipment broken down and containerized for shipment. So, you’ve saved $25,000 on equipment but paid out an extra $15,000 in labor compared to buying a new system. So, you’re still $10,000 ahead—until a problem crops up.

What if some panels get damaged because they were screwed together instead of being held together by friction the way they should be? Perhaps the heat unit breaks into two pieces because the original installers failed to assemble it correctly. There’s no way an independent installation crew is going to absorb these costs because they didn’t build the equipment the first time. The original manufacturer is unlikely to offer to provide labor because they don’t want to inherit a bunch of problems or assume any liability from the previous owner.

When working with factory-authorized crews that are assembling new equipment, installation goof ups should get taken care of free of charge. When dealing with used equipment, the meter never stops running. You have to deal with the unexpected costs. It is easy to end up spending so much on labor and repairs that the deal you got on your used powder coating equipment is no longer a bargain.

These are just a few of a multitude of issues to be aware of when considering buying used powder coating equipment instead of buying a new powder coating system. Many of the problem issues can be monetarily quantified, so you can decide if the risk is worth it, but the peace of mind that comes from buying a quality powder coating system with a warranty, professional installation and years of factory support is hard to measure.

Three Common Powder Spray Booth Misconceptions

Misconception 1: If you buy a high-quality powder spray booth, you won’t need to change the filters often.

Powder Spray Booth Bag Filters Comparison

Every powder spray booth needs to have the inexpensive filters changed regularly. Not changing the filters can significantly reduce performance and damage the equipment.

No matter how well designed a powder coating booth is, the filter media that it uses can make or break its performance. One of the biggest misconceptions around is that a good booth doesn’t need expensive filters or doesn’t use cheap ones up quickly. All o powder spray booths either have very expensive cartridge or cyclonic exhaust filtration systems or use disposable filters that must frequently be replaced. A booth that is cheap on filters isn’t doing its job!

Powder Spray Booth Bag Filter Saturated With Powder

One of the main reasons that shops buy booths is because they want to turn out better quality powder coated finishes. They need to be able to get a clean finish every time. They also want the booth they buy to be long lasting and dependable. By using cheap filters or running equipment with dirty filters (or even worse, without filters), the owner saves a little in filter expense but costs the shop a great deal over the long run. A booth that uses disposable filters but doesn’t get frequent filter changes won’t have enough airflow to get top-notch results. Trying to stretch things out by postponing filter changes only makes the equipment’s performance decline further.

Powder Spray Booth Blanket Filter Saturated With Powder

Many powder spray booths are equipped without doors. If you have a relatively clean shop, filtered doors or wall or roof-mounted intake filters aren’t a necessity when working with powder, but compromising on exhaust filtration is a mistake. Using a cheap panel or blanket filter instead of a cartridge filter system or multi-stage disposable filter system may reduce a shop’s filter costs, but it means that debris gets blown back out into the shop atmosphere during use—which creates an increase in airborne contaminants. More contamination translates to more reworks. The reason you don’t have to change cheap filters as often as premium filters is because they are not filtering out as much trash and overspray. It also usually means that the exhaust fan is taking a beating from airborne dirt and powder overspray. Over time, powder builds up on the exhaust fan, reducing the amount of air it can move and adding stress to the motor and drive system.

By using inexpensive filters or using filters beyond the point that they should be changed, operators increase their long-term costs for a variety of reasons: clogged filters reduce the effectiveness of the exhaust and make it harder for the coater to do a good job, poor filter maintenance results in more incidents of booth down-time, increased dirt in the finishes means more reworks, inconsistent performance keeps the coater from mastering booth and gun operation, etc.

Powder spray booths from Reliant Finishing Systems all use premium filters and we recommend regular filter changes.

Misconception 2: All powder spray booths that have the same airflow rating (such as 12,000 CFM) work about the same.

When purchasing a powder spray booth, know what kind of fan(s) the exhaust system uses so you can anticipate how the booth will perform as the filters begin to fill with powder.

Powder spray booths all have exhaust fan systems that are rated based on how much air they move. This is measured in cubic feet per minute (CFM) of airflow. Some companies improve their ratings by using theoretical values. Basically, they use a performance rating that can only be reached if the exhaust has been detached from the booth and filters. To understand how robust a booth’s exhaust really is, it’s critical to find the static pressure at which the booth’s airflow is being measured. This is measured in inches of water column (shown by using the inch symbol with or without the initials w.c. or s.p.). In order to compensate for the restrictions of filters, ductwork, etc., on the exhaust of a powder spray booth, the rating should be at 1” or more of static pressure in order to be meaningful. Powder spray booths from Reliant Finishing Systems are typically rated at 1.25” to 5.75” of static pressure, depending upon the type of booth and exhaust.

There are two main types of fans that are used in powder spray booths and ovens: “propeller” style and “wheel” style. Propeller style fans include tubeaxial fans, some so-called turbo fans and others. Wheel fans include single and double inlet forward-curving fans, barrel fans, backwards-inclined fans, “squirrel cage” fans, and others.

Propeller style fans work well at lower static pressures. They’re usually not as efficient under load and they tend to be noisier, so they are less common on automated or constant-process lines where the exhaust must overcome the load of a restrictive, low maintenance filter system. Since powder spray booths use filters that increase the load the fans must overcome, propeller style fans can run out of power unless they are configured with adequate motors mated to ideally sized blades. Contaminated filters can reduce a low quality or underpowered 12,000 CFM propeller fan to less than 8,000 CFM with no real warning except for poor air movement. When considering a product that uses a tubeaxial fan, make sure that the advertised airflow is at a reasonable static pressure.

Powder Spray Booth With Tubeaxial Fan

A premium quality tubeaxial fan, mated to a reliable motor of adequate horsepower, can provide good exhaust performance at an economical price for a spray-to-waste type booth.

Some units use a backwards-inclined wheel fan that creates a vacuum on one side as it spins. These fans perform well under high static pressure, but their maximum airflow is quite limited—often 10,000-12,000 CFM or less on a large walk-in sized powder spray booth. They are typically well made and more expensive than tubeaxial fans, but suffer from a lack of efficiency because their maximum output requires a much larger motor than many other fans. They overcome high static pressure loads, but this may be unnecessary if the booth is maintained properly and is being used for a spray-to-waste process.

If you are thinking about reclaim for your powder operation, remember: Almost all systems where the powder media will be reused feature reinforced wheel type fans. These exhaust systems are typically more expensive, but are necessary when working with cartridge type filtration modules.

Squirrel cage fans provide premium performance under moderate load. They are smaller, quieter, and more efficient than many other designs. The dual inlet/dual outlet forward curving fans used in some booths achieve a balance between maximum airflow and the amount of load they can overcome. Because the blades are smaller, better formed and more rigid in these fans, they distort less when they meet resistance. These types of fans are not as widely used because they can be costly and their advantages are greatest for buyers of booths built for very specific powder coating applications. A small dual-inlet squirrel cage fan can move more air than a larger backwards-inclined wheel type fan and can outperform much larger propeller style fans under moderate load.

Misconception 3: A powder spray booth needs to have lights in the walls and should be very bright inside.

Powder Spray Booth With Lights

OSHA and other independent organizations have determined that a painting enclosure needs about 100 to 150 foot-candles of light at the object being painted to reach an ideal painting atmosphere—from safety, ease-of-use and production efficiency standpoints. Too much light or poor light quality can detract from this environment. The bulbs used for illumination should have very accurate color rendering to get the best results. Many bulb providers offer high-intensity bulbs that have a rating of over 90 CRI and a color temperature of over 5000° Kelvin. These specially formulated bulbs cost more, but they provide broad spectrum illumination much like natural sunlight. The concept is to match a cloudy summer day where the light seems a little hazy and diffused. Blasting the parts with lights–the “more light is better light” approach–is scientifically unsound. The human eye best discriminates color when the colored surface is compared to a background that is about 18% gray, not glaring white.

Well-designed booths help coaters see problems before the parts are moved to the oven to be cured. Coaters also get better color matches. A white powder spray booth interior can be helpful, but a conventional galvanized booth can work fine–if you keep it clean! All of Reliant Finishing Systems’ flat roof booths are designed so that a large portion of the light bounces from our ceiling-mounted fixtures onto the booth walls and then onto the surface of the object being painted. The light is somewhat indirect and much like a cloudy summer day. At the level of most surfaces being painted, the booth walls are not glaringly bright because the light from the ceiling fixtures has dissipated. This is the ideal painting atmosphere for accurate color matching, touch-ups and detail work. Our lighting method creates lighting that is more even in tone. A typical Reliant powder spray booth provides about 150 foot-candles at the center of the booth.

Wall-mounted lights make detail work harder and hinder color matching. The painter has to look directly into these lights when he is painting across from them. As a result, backlighting causes the painter to perceive that the surface being painted is darker than it really is. This can cause the painter to miss critical details. Also, he casts a shadow on the parts he is painting whenever he stands in front of a wall-mounted light. As a result, he ends up trying to work on parts that are poorly lit due to his own shadow. Even worse, when overspray gets on the wall-mounted lights, they can tint the perceived color of the object being painted or obscure critical details. A little bit of blue powder faintly covering part of the lights would give a section of a yellow part a faint green cast, making it harder to judge powder coverage. Wall-mounted lights require extra maintenance to prevent botched jobs.

Hip-mounted lights can lead to finish quality problems. Booths for wet paint applications that have “hip” style roofs are popular in the collision repair industry because they are cheaper to buy and easy to service. Some of these booths have been adapted for use in the powder coating market, though they are not ideal. This design typically has lights mounted in the hip panels because the ceiling is so small that there isn’t enough room for all of the lights. Some inexpensive hip roof booths also have very short side walls. As a result, a portion of the light coming from the fixture behind the painter is blocked by his head when he works close to the center of the booth. This causes the painter to work in his own shadow. As explained previously, this is not a situation where your painter can excel.

Some parts are harder to light than others. Even with well-designed indirect lighting, if you have a ceiling-to-ground object that fills the powder spray booth, or one with curved surfaces (like a fuel tank or an antenna dish), the bottom part of the object may be somewhat shadowed because it is curved so heavily. The correct solution is not to add lights, but to adjust throughput expectations and allow the coater enough time to do a good job. In exceptional cases, a shop may choose to add a better reflector, such as white floor tiles or stain-proof white floor paint when practical.

By doing research before you acquire a new powder spray booth for your operation, you can help prevent unpleasant surprises and disappointing equipment performance.

Need advice about your powder spray booth? Contact Reliant Finishing Systems at (888) 770-0021 and ask for a powder coating systems specialist.

What Size Powder Coating Oven Do You Need?

Powder Coating Oven - Frontal ViewIf you’re looking to buy a new powder coating oven, one of the first things you should determine is how big the oven will need to be. The size of the oven determines what kind of work you can do and how much work you can get done at one time, so making sure you have the right size appliance for your operation is critical.

Most of our discussion in this article is aimed at conventional batch coating equipment, but many of the factors can be applied to automated or constant process situations. (For more information on matching equipment, please visit our Powder Spray Booth Size Guide.)

How Big Is The Largest Object You Want To Powder Coat?

Powder coating ovens can be built to nearly any height, width or depth. When you acquire a new curing oven, the ideal size is dependent upon what you are going to be coating. No matter what you want to coat, the entire object needs to fit inside the oven without being jammed against the ductwork where the heated air enters the oven. Hot air is usually blown into the oven via ducts in the ceiling or walls. You can’t position parts too close to the ducts or the powder can get blown off. The parts can’t touch the ceiling or walls either, and they can’t impede the operation of the doors. If a part touches the oven’s ceiling or walls, the powder is likely to either rub off or flake during curing. When it does, you’ll need to redo the part to get a proper finish.

Also consider how the parts will be carried in and out of the oven. Most parts are hung on rolling racks and there has to be enough room for the rack to fit into the oven once the parts have been hung. If your rack or cart bumps into the walls of the oven, the powder you just applied can get knocked off. Take racks into account when sizing your new oven.

One last thing to consider is the performance of the oven. Some ovens have better temperature uniformity than others, but none are perfectly uniform. Ovens with ceiling ducts are usually cooler at the floor than elsewhere. Ovens with wall ducts may be cooler in the corners, as well as near the floor. Just like you will need to allow room near the walls, ceiling and ductwork, you also need to avoid hanging parts so that they nearly drag the ground. If possible, size your oven so that the biggest parts are still 10” or more off the floor. This helps improve the uniformity of the temperature of the parts, which enables a better finish. It also helps prevent dust contamination, which can occur when the oven’s heat system blows dust and dirt from the floor onto the parts.

IMPORTANT: When sizing, make sure the part you are coating will fit entirely inside the oven without angling. Many new coaters buy 20’ long ovens because they want to be able to coat 20’ lengths of material like handrail or tube stock. To fit 20’ lengths of material into the oven, they have to be rolled in at an angle so they are positioned diagonally inside the oven, or they have to be hung at an angle with one end much closer to the floor than the other. Otherwise, they will touch the doors and/or the back wall. These positions are not very efficient because you can’t fill the oven with material if it has to be tilted to one side or hung at an angle. If you want to cure 20’ lengths of powder coated material, buy an oven longer than 20’.

How Many Parts Per Day Do You Need To Powder Coat?

Determine your production throughput requirements. When we say throughput, we’re talking about the number of parts powder coated during a given shift, day or work week. One of the easiest ways to get the correct amount of throughput is to get the right size powder coating oven to start with. For example, if you are frequently powder coating rims, but only need to coat four at a time, a small walk-in oven will suffice. However, if you need to coat forty rims at a time, a larger powder coating oven will help you reach your production goals with less work because you won’t get bogged down with handling issues as you load and unload the oven over and over again to reach your goal.

Throughput is tied to pacing. One thing that can slow down your operation is if your coaters have to be extra careful moving parts in and out of the oven because the rack fits too tightly into the oven. That delay, even just a couple minutes at a time, can significantly decrease throughput as the parts are moved over and over throughout the day.

How Much Space Do You Have For Your Powder Coating Oven?

This seems self-explanatory, but every year we hear about shop owners or coating line managers that didn’t correctly measure the available space in their facilities. If you need a walk-in sized powder coating oven, you are dealing with an appliance (and installation space) that is larger than it looks, so we always recommend tool-measuring the available space before making any purchasing decisions. You must account for low ceilings, odd roof grades, inconspicuous purlins or trusses, floor issues, HVAC/fire suppression/electrical/air/gas runs, posts or columns, unusual structural steel, lighting or anything else that might impact the installation or operation of the equipment.

In addition to the appliance itself, you will need to account for staging areas. We recommend at least two staging areas for your powder coating oven. First, you’ll need a designated area where the parts will sit prior to being loaded into the oven. This area should have no traffic if at all possible, as any handling or jostling in this area can knock off powder that was just applied in the booth. Second, you’ll need a separate cool-down area once they parts have been cured.

Another thing to keep in mind is that most carts can’t make a true 90° turn, so allow for the turning radius of each cart and don’t place equipment too close together.

Determine The Exact Footprint And Dimensions  – Don’t Guess.

All of Reliant Finishing Systems’ powder coating ovens are sized using the actual interior dimensions. Our popular PCO8825 is 8’H x 8’W x 25’L INSIDE the cabin. The exterior dimensions add an additional 2′ of height for the overhead plenum and insulated roof, plus an extra 1′ to both the width and length because the walls and door assemblies are 6″ thick. So, a PCO8825 is actually 10’H x 9’W x 26’L. In addition, each powder coating oven comes with at least one heat unit and exhaust fan. The heat units have a 4′ x 4′ footprint when erected, and are as tall as the oven. The exhaust adds another 27” to the oven’s overall width or length, depending on mounting location. A typical 8’H x 8’W x 25’D powder coating oven with a rear-mounted heat unit and side-mounted exhauster will require a space that is over 10′ tall, a little less than 12′ wide and about 30’ deep.

IMPORTANT: Don’t forget to allow room for the swing arc of each set of doors on the oven, and remember that local codes may require 3′ of clearance around the entire oven.

Plan For Success By Allowing For Growth!

Nobody ever says, “I should have bought a smaller oven.” We tell anyone considering a new oven to purchase the largest powder coating oven they think they will ever need. Although our ovens are modular in design and can easily be expanded, it is more affordable to get a larger oven right from the start.

Why go big? If you are planning on opening a powder coating job shop, the larger the powder coating oven you get, the more jobs you can potentially take in. A large oven allows you to take on bigger projects, such as coating exceptionally long, tall or wide parts. You can also coat handrails, structural steel or fence sections in bulk. Since you can’t effectively cure a part that won’t fit completely inside your oven, the size of your oven dictates the biggest job you can ever take on. It only takes a few of those big jobs to more than pay for the upgrade to a larger oven.

If you’re a manufacturer bringing your coating work in-house, your coating line’s productivity is going to be closely tied to the size of your powder curing oven. A bigger oven pays off because it allows you to do larger batches of regular-sized parts at the same time. If you are going to be doing parts smaller than about 4’ x 4’ x 4’, it is easy to justify buying a large truck-in or small walk-in oven. But, by installing a larger oven, you can ramp up your production capabilities and dramatically increase your throughput. You can also use the extra oven space to help catch back up if you have problems or encounter unexpected reworks.

Still have questions about the size of the powder coating oven you need? Our systems specialists will be glad to help you get the exact system you need. Give us a call today.

Get The Best Finish From Your Powder Spray Booth With These Five Tips

powder spray booth trainingWant to get the absolute best finish possible when powder coating? Whether you just invested in a new coating system or you want to improve the performance of your existing powder spray booth and powder gun, here are five great tips to help you get the most out of your equipment and improve your finish quality.

Before You Start Powder Coating, Make Sure Your Parts Are Clean

No matter what you are powder coating, if your part has any residue, grit, grime, rust, oil or dirt on it, your powder coating quality will suffer. Anything left behind on your parts can cause your powder coating to crack, bubble or flake during the curing process, so you need to make sure every part is clean BEFORE you apply the powder. Whether you need a simple detergent wash and rinse, abrasive blasting and wipe-down, or a multi-stage phosphatizing pretreatment option (check the Reliant’s equipment here), don’t skimp on parts prep. The number one thing that assures a quality powder coated finish is parts cleanliness. (For more on getting your parts clean, read Bruce’s article on pretreatment here)

Make Sure The Parts In Your Powder Spray Booth Have Good Ground

Powder coating is easier to do than wet paint, primarily because the powder sticks to the part as it is applied. That’s because the particles from the powder gun are charged, and your part in the powder spray booth is grounded. The powder is attracted to the part and will form a uniform layer if it is applied with a bit of skill. If you find the powder doesn’t want to stick, or you’re having trouble getting the powder to go on uniformly, make sure your parts are properly grounded. We always recommend using a ground rod that can be connected to your rack, hook or directly to the part– and in some locations you may need a ground rod of 8’-10’ to get best results. (See our article on proper grounding for more information.)

Buy High Quality Powder And Store It Correctly

Fresh powder should be fluffy and without clumps. Storing powder in areas that are hot and humid can quickly cause the powder to become moist and clotted, so find a way to keep your powder dry and relatively cool. Reclose open powder containers promptly to prevent contamination. If you have a good ground and your gun is set up properly, you shouldn’t have a bunch of powder hitting the floor while you spray.

Remember, all powders are not created equal! While all powders have a certain amount of inert filler material, inexpensive powders often have much more of it. Just because a powder costs less doesn’t mean it is the best value. If you want better finishes, buy the best powder you can afford and take care of it.

Give Your Painters The Best Light To See Their Work

Keep your powder spray booth’s light fixtures clean and keep them supplied with fresh wide-spectrum bulbs that are designed for paint booth use. If you have bulbs that are burned out, replace them! It’s amazing how many shops have booths with light fixtures that are caked with powder. Instead of coaters working in light that is about the same quality as sunlight, they’re stuck spraying with green or red or blue light glaring out of fixtures that haven’t been cleaned in months. Problems can also happen in shops that use cheap bulbs that have a warm, off-white color that’s very unlike natural sunlight. Spend the money on wide-spectrum bulbs that have a high color temperature and mimic natural sunlight. This gives coaters a chance to more accurately assess and match colors. Keep the booth clean and the bulbs fresh so they can see fine details and turn out better quality work.

Check And Change The Filters On Your Powder Spray Booth Regularly

If your filters are damaged or clogged, you won’t get good results from your powder spray booth. Almost all booths work on the same principle—air is drawn into the booth from the shop, travels across the part, goes into filters, and then is either returned to the shop or discharged into the outside environment. When filters begin to clog, they put more stress on the exhaust fan. The fan doesn’t perform as well, and less air moves through the booth. This can cause problems with visibility inside the booth and can impact the quality of the finish being applied. Damaged filters can cause the airflow through the booth to change unpredictably. They are often the result of improper handling or poor maintenance. Once the booth’s filters are damaged, you’ll probably end up having to clean the booth’s exhaust system from one end to the other to prevent an on-going problem.

Reliant’s recommended filter change schedule will help you keep your powder spray booth in the best shape.

If you are using a Reliant Finishing Systems powder spray booth, you probably have a three stage spray-to-waste filter system that uses a blanket, a set of polyester “cube”  or bag type filters and a set of true HEPA final filters in metal frames. Alternatively, you may have an array of cartridge filters and a set of panel type final filters. In our standard spray-to-waste booths there are three filters you need to check:

A) The blanket filter is the first line of defense and usually lasts between 3 days and 2 weeks. This filter media is very inexpensive. As a general rule, trying to vacuum and reuse the filter is unwise.

IMPORTANT: Never spray the blanket filter with compressed air in an attempt to dislodge powder trapped in it—you’ll damage the filter and ruin the other filters in the booth if you try to reuse it! Just cut off a new section of filter and replace it once it is clogged.

B) The cube-shaped bag filters are located directly behind the blanket filter. Depending on how often you use the powder spray booth, you’ll typically need to change the bag filters once every 2-4 months. They can collect up to several pounds of powder, which will make them distort and stop working properly. Make sure to service them before the wire frames inside them warp and powder begins to go around them and directly into the HEPA filters! You can vacuum out the bag filters to extend their service life, but remember to take them out of the booth first. We recommend that whenever you replace the blanket filter that you remove, clean and then rotate the bag filters 90° before reinstalling them. This serves to even out the wear and will significantly increase the life of the filters.

IMPORTANT: Never spray the bag filters with compressed air in an attempt to dislodge powder trapped in them—you’ll damage the filters and ruin the HEPA filters in the booth if you try to reuse them!

C) The HEPA filters are the last filtration step before venting the booth’s exhaust back into the shop environment. If your other filters have been cleaned regularly, the HEPA filters should last about 1,000 hours – which works out to anywhere from 6 months to a year and a half in most powder shops. These filters can’t effectively be vacuumed without damaging them. It is possible to gently tap a clogged filter’s frame while holding the filter with the intake side pointed down at the floor and dislodge a small amount of powder. This can be repeated a few times to extend the filter’s life slightly.

IMPORTANT: Never spray the HEPA filters with compressed air in an attempt to dislodge powder trapped in them—you’ll ruin them instantly!

In our standard booths that use cartridge filtration there are two filters to check:

A) The cartridge filters are typically cylindrical filters that have a pleated fibrous exterior. They are the first filtration step before venting the booth’s exhaust back into the shop environment, and they do the bulk of the work. All of Reliant’s cartridge systems use pulsed air cleaning to periodically discharge built up powder from the outside of the filters. If it has been set up and maintained properly, the cartridge filters should last 1,000 to 2,000 hours – which works out to anywhere from 6 months to three years in most powder shops. These filters can’t effectively be vacuumed without the risk of damaging them. Also, it is possible to accidentally damage cartridge filters by using compressed air that is dirty, oily or wet to supply the pulse cleaning nozzles.

IMPORTANT: Never remove and spray the cartridge filters with compressed air in an attempt to dislodge powder trapped in them—you’ll probably damage them and you risk ruining the other filters in the system if you try to reuse them!

B) The panel filters capture any dust that gets past the cartridge filters. They help assure that air being returned to the shop environment is clean and powder-free. Depending on how often you use the booth, you’ll typically need to change the panel filters once every 2-4 months. These filters are relatively inexpensive, and, as a general rule, trying to vacuum and reuse them is unwise.

IMPORTANT: Never spray the panel filters with compressed air in an attempt to dislodge powder trapped in them—you’ll ruin them instantly!

For more information on a Reliant powder spray booth, click here, or give us a call today.

Innovative Powder Coating Oven Airflow Leads To Improved Performance

Powder Coating ovens from Reliant Finishing SystemsAt Reliant Finishing Systems, we pride ourselves on providing some of the most energy efficient powder coating ovens in the world. Our ovens reach curing temperatures much faster than many of our competitors’ ovens and at a fraction of the operating cost. If you need a powder coating oven that can provide professional quality results on a daily basis, a U.S.-built oven from Reliant Finishing Systems will get the job done, and it all starts with the powder coating oven airflow.

It Starts With The Airflow

Reliant’s innovative design uses one or more powerful direct-fired burners to heat the oven through an overhead plenum. Hot air is injected from the plenum directly through the oven’s ceiling. Each heat unit continually pulls the coldest air from the bottom of the oven back through the burner to be reheated. At the same time, the exhaust is constantly pulling cold air from the floor and enabling hotter air to move into every corner of the oven’s interior. This combination of vertically positioned heat units and floor-mounted exhausts is unique—and just plain better.

Reliant Powder Coating Oven Airflow

Typical airflow of a Reliant powder coating oven with a side-mount exhauster and rear-mounted burner and heating unit.

By comparison, many other ovens on the market use both roof-mounted heaters and roof-mounted exhaust units. We don’t use this design because it makes routine maintenance tasks and inspection much more difficult – the operator has to climb on top of the unit every time anything needs to be checked. Also, top-mounted heat units and exhaust units remove the hottest air from the oven instead of the coldest. Why would our competitors build ovens this way? The answer is that this design is much cheaper to build.

With a Reliant powder coating oven, since we’re taking the coldest air from the bottom of the oven in a constant cycle, the oven air is much more evenly heated throughout the cabin. This has two major benefits. First, the oven quickly reaches a very stable temperature. Second, that constant temperature means you won’t have to deal with hot and cold spots in your oven. By eliminating temperature inconsistencies, the powder can cure evenly and uniformly without the potential for flaking, undercuring, or overbaking. That means a better and longer-lasting finish.

But what does that mean for you? Because our ovens get to temperature quickly and sustain that temperature evenly, they require far less fuel to operate. Typically, our customers using standard models can get their ovens to 400 degrees or more within 10-15 minutes, and maintain that temperature for an entire production day with minimal energy costs. For one of our most popular models, an 8’ x 8’ x 20’ walk-in oven, heating costs are often as low as $3 per hour on average.

Get The Most Efficient Powder Coating Oven From Reliant

Reliant’s superior airflow design is just one of the reasons why we’re so proud of our powder coating ovens. A Reliant powder coating oven is built to give you reliability, fuel economy and top-notch performance at an unbeatable price. Don’t just take our word for it, ask for references so you can talk with our customers about the incredible results they are getting every day with Reliant equipment. Click here for more information on our powder coating ovens and related powder coating equipment, or give us a call today.