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What Finish Do You Need?

We’ve already talked about the benefits of powder coating over traditional wet paint and how setting up your own system can save you considerable time and increase your ROI. But what do you need to do now that you’ve decided to start your powder coating operation? Understanding what you are going to coat and what your powder specifications are will help you make the right decisions.

Determine What Type Of Powder Coating Finish Your Customers Want

When you start your powder coating operation, you need to know what performance specifications your customers require. This can be as easy as matching the performance of your current liquid operation or using the same powder as your current outsourced job shop. However, if you are in a highly technical industry – like supplying car or tractor parts – then there could be specification on salt-spray resistance, color retention, gloss loss, adhesion, flexibility, or hardness.

Here’s an example: If you powder coat parts for a larger manufacturer, that manufacturer may already powder coat and assemble some of their larger parts in-house. If you are, for example, supplying powder coated parts to John Deere, you will be using the same powder they use for their products. There might be no way to match their pretreat process, but you will need their powder specifications to make sure your parts integrate smoothly with their operation.

The Powder Specification Indicates What Equipment You’ll Need

The powder specification will provide you with a lot of important information, including powder thickness and cure times. This will tell you what type of oven (https://www.reliantfinishingsystems.com/powder-coating-equipment/powder-coating-ovens/) you will need as well as how much powder you have to apply. Is the thickness excessive? If yes you might need to pre-heat the part to get more powder to stick. The specifications should also say what type of pretreat process is required before coating. Iron Phosphate or Zinc Phosphate might be designated. Zirconium is also a common pretreat chemical that is used for multi-metal pretreating.

These specifications will dictate what type of pretreatment process you will need as well as what type of finish process your products will require. Once you have decided that, then you need to figure out how many you want to coat a day.

Choosing The Right Equipment For The Job

Your finish process is very dependent on the type of powder the finish specifications require and your coating equipment must be able to handle the workload in a quick and efficient manner.

For example, if you have to use a super-durable polyester baked at 385-400 F for 10-15 minutes, then you need an oven that is large enough and has enough power to cure the powder in an even and timely process. But if you are coating low cure epoxies, they only needs 8-10 minutes at 325 F for full cure. You wouldn’t need as powerful an oven to cure the epoxies as you would with the super-durable polyester.

If you plan on doing both, then engineer your equipment to the higher end. I always ask manufacturers to look five years down the road for their projected production requirements and possible finish improvements they would like to see.

Asking the Right Questions Before You Get Started

Ask your powder supplier for the curing and application specifics. This will help you decide on the basic system you would like to implement. Not all powders are the same though many are similar. Remember cure time is part temperature at cure time. The heating up of the metal does not technically count as cure time.

Your Process Decides Basic Equipment Selection

Once you know your proposed finish process, you can easily decide which equipment is right for you and your customers. Finishing can be broken down into three basic elements which help inform you on what sort of equipment you’ll be installing:

Metal Preparation – sand-blast, cleaning, solvent wiping, pretreating, and/or drying

Application – hand-spray, multiple coats, automatic spray, and/or possible priming

Curing – batch oven, conveyor oven, and/or IR oven

We have a lot to talk about in future articles, including pretreatment selection, powder chemistry and equipment selection, but suffice to say, having the finishing details first helps with the more expensive equipment decisions later.

Need help? Please give one of our systems specialists a call today, or check out our Resources page for more educational information on coating equipment, powder coating and more.

 

Bringing Your Powder Coating In-House

We’ve already covered many of the advantages powder coating has over liquid paint: how it can cost you significantly less and is more durable all while being a cleaner and safer process. This time we will discuss when manufacturers are outsourcing their finishing to a job shop and are deciding whether or not to bring their powder coating in-house.

Yellow Powder Coated Rims

Adding a powder coating line can help increase quality and reduce cost. (Photo courtesy of Espo’s Powder Coating in New York. Reliant equipment shown).

Getting Control Over The Finish

Every manufacturer I’ve worked with told me that improved quality was the number one reason for bringing their finishing in-house. This isn’t to say all job shops have poor quality, but they may not have the tight specifications that the manufacturer would like. Irregular thickness, adhesion problems, surface defects, gloss, color mismatch, and damage are all characteristics of outsourced coatings, and all of them create costly delays. For many manufacturers, adding an in-house line was easily worth the investment to control the defects from their outsourced partners .

The Costs of Outsourcing vs Coating In-House

As an example of typical powder coating costs, I looked at a large chain automotive parts retailer. To buy an uncoated wheel rim it costs roughly $50. For this same wheel rim, it costs $100 for a single color powder coat. For an exotic two-coat color (such as Hyper Silver) the wheel rim can reach $450. Granted the last wheel is far more stylized and the finish must be perfect, but the mark-up involved can be substantial.

Outsourced Cost: 4 Rims x $50.00 = $200.00 + Freight

In the above example, if brought in-house, the materials cost for doing a set of 4 wheel rims would be about 1 pound of powder. Say $7.50 a pound for a normal color. Pretreatment chemicals would cost about $0.50 per gallon of water. You would use approximately 2.5 gallons of water to clean 4 wheel rims, so $1.25 for chemicals. Well-insulated ovens have a gas/power cost of about $5-8 an hour, so let’s say $6.50 an hour. It only takes ½ an hour to cure the 4 rims, so energy cost of $3.25. Labor would be approximately $20 an hour and you could cycle 4 rims every 30 minutes, so $10 labor in 4 rims cost.

In-house Cost: $7.50 (1 lb of powder) + $1.25 (pretreatment chemicals) + $3.25 (Oven operating cost) + $10 (1/2 hour labor) =  $22.00 for all / $5.50 per rim

The total part cost for finishing in-house would be $7.50(powder) + $1.25(pretreat) + $3.25(oven) + $10 (labor) = $22 for 4 rims or $5.50 cost per rim. This is a rough estimate and doesn’t include all costs but if the wheel manufacturer was having their wheels painted somewhere else, the $50 cost versus $5.50 cost is significant. This example also only factors for a small batch of 4 rims; with a larger coating production run, the in-house cost goes down even further.

Manufacturers know their cost of outsourcing by how much they pay per part. But there are other costs besides raw production to consider. Shipping the part back and forth, packaging the part, inventory costs of parts coated and waiting to be coated, delay of available parts costs, and damage to parts are all factors when comparing outsourced to in-house coating.

Flexibility and Rush Delivery Favor In-House Operations

Often times manufacturers need a small parts run fairly fast to avoid costly delays. Whether you’re replacing something that may have been fabricated wrong, or a slip up on a pick list that they didn’t have the correct inventory, being able to fix these issues prior to shipping is valuable. Having the powder coating in-house allows for quick turn-around for these and other unforeseen issues. As we’ve already discussed, since powder coated items can be finished, cured and packed quickly, having the ability to coat in-house can save days of delay.

 Having your coating in-house is also instrumental for the research and development of new colors or new fabricating designs that you would rather keep private. This finishing flexibility allows for the experimentation with new technologies and improved quality processes that can give companies a competitive advantage.

Deciding When an In-house System Is Right For You

When deciding whether to install a new powder coating system in your operation, the real challenge is comparing all your costs to see if the benefits are worth the investment, labor and learning curve of developing a good finish process. Training and flexibility are very important when starting a new finishing process, as is setting realistic goals or expectations (though we can certainly help you get up to speed with your new equipment). Remember to keep a good relationship with your job shop vendor, since you may need them in the interim and if your finishing capacity gets maxed out.

Ultimately, if you are only coating a few things a year and don’t anticipate adding powder coating to your process, outsourcing can be a very effective way to handle your coating needs. However, if you’re already outsourcing a sizable amount of work every month and are concerned about cost, quality or delivery deadlines – or all three – it’s time to consider bringing you powder coating in-house.

Looking for additional information to help your purchasing and powder coating operation? Please check our Resources page.

Advantages of Powder Coating Over Liquid Coating

In the previous article, I talked about pure cost per square foot savings and general material cost savings of powder coating over liquid coating. Today I’ll discuss some of the other advantage of powder coating that can save you significant time and money.

Curing Times Are Significantly Faster With Powder

Powder coating can help you get the results you want in a fraction of the time.

Powder coating can help you get the results you want in a fraction of the time.

The average catalyzed automotive or industrial liquid polyurethane is 2-4 hours cure to touch. The drying time can be accelerated by baking at around 235 F for 45 minutes, but that will only get the parts dry enough for limited handling. In most case, an extended cure time of about 1 hour is required before the parts can be assembled. Most liquid coated parts cannot be packed for shipment unless they have had an overnight dry time.

After the metal reaches a part temperature close to 400 F, powder coating cures on average in 10 minutes. Sometimes thick metal requires 30-45 minutes in the oven (and sometimes longer for especially dense objects). But after the part has cooled to handling temperature, it can be assembled and packed right away. Powder coating results in hours of saved process time and fewer parts in inventory waiting to be assembled or shipped.

Environmental Impact And Flammability Concerns Are Significantly Decreased With Powder

The average VOC (volatile organic content) of liquid coatings is between 3.5 to 5.5 pounds per gallon. This usually means about 1/3 to ½ of a gallon of paint goes into the atmosphere as emitted solvents. Many manufacturers have limits on how many tons (yes tons) of solvent they can put into the atmosphere. They have to pay for permits and will pay fines if they exceed their limit on these emissions. Powder has zero emitted solvents and no solvent flammability concerns. Using powder simplifies the permit process, reduces insurance risk, and generally provides a much more environmentally friendly process.

Processing Time And Number of Coats Are Greatly Reduced With Powder Coating

A regular polyester powder coating is comparable to a two component liquid polyurethane over an epoxy primer. Both systems need good clean metal that has had some kind of pretreatment to achieve maximum salt spray resistance. The liquid system then needs an additional primer to aid the topcoat in further durability and adhesion. Powder can eliminate the primer and be directly applied to the clean pretreated metal.

Powder also is 100% solids while liquid coatings average 50% solids. So if you have a paint thickness specification of 4 mils DFT(dry film thickness), then you can achieve this with one pass of powder. It will take 2-3 passes of the liquid coating, with some dry time in-between, to achieve the same thickness.

Powder Coating Is More Energy Efficient Than Liquid Coating

Powder coating equipment is generally much more energy efficient than equipment used for liquid paint. Because of safety concerns, liquid paint equipment uses more air and requires more air changes to filter out VOCs.

A liquid paint booth sized at 8’H x 10’W x 10’L uses approximately 16,000 cfm. A similarly sized powder spray booth uses approximately 8000 cfm, half what the liquid booth does. This means smaller fans and less shop air drawn through the booth when using powder. Liquid booths must also be exhausted to the outside to vent their emitted solvents. Since powder coating has no solvents, powder booths can be exhausted back into the shop by using HEPA filters on the final filter. The air is cleaner than the supply air that went into the booth.

If you are using a liquid coating oven to reduce your drying time, it will require more air exchanges than a powder coating oven. Since the powder oven can recycle its hot air more, it uses the burner less, thus saving energy.

Start Your Operation With Quality Equipment

Reliant Finishing Systems is a U.S. leading manufacturer of efficient and affordable powder coating equipment, from small batch systems for rims and wheels to large automated systems for constant throughput and rapid production. Whether you need to replace your existing coating equipment or are bringing a new operation in-house, our systems specialists can help. Give us a call today.

If you are looking for more educational information, please check out our Resources page.

 

Switching From Liquid Paint To Powder Coating: What You Need To Know

Powder coating is a more economical and longer lasting alternative to traditional wet paint application with far less environmental impact. If you’re comparing these two finishes from a production standpoint, here’s what you need to know.

Powder Coating Is More Durable Than Liquid Paint

Powder Coated Pipes

Powder coated items are more durable and last much longer compared to liquid paint.

Switching from liquid coating to powder coating has many advantages. From a performance perspective, powder coating is more durable physically and chemically. Most liquid coatings are typically softer than an average powder coating. When coating parts like semi-truck wheel rims, this improved durability and corrosion resistance make trucks safer and longer-lasting. In the oil fields, replacing corroded pipes or junctures is expensive and leads to oil flow downtime. These parts and fixtures are perfectly suited to powder coating and benefit from its performance advantages.

Powder Coating Is More Efficient & Easier To Use

If you’ve worked with liquid paint, you know that mistakes can be time-consuming and costly. In comparison, powder coating is generally much easier to apply. Operators require less training to apply a quality finish and mistakes can be easily fixed with powder (as long as you catch them prior to curing). Since rework issues are fewer and coating is usually faster, you can coat more items on a given day. You can expect increased throughput with fewer errors by switching to powder coating.

Most Importantly, Powder Coating Is Cheaper  

Cost savings are another great benefit to powder coating and often provide a very fast return on investment.

Since everyone has different size and shaped parts they need coated, we can determine ROI by calculating a 1 square foot panel cost. For this example, we’ll eliminate the labor and fixed costs and focus on just material costs. This will show the cost savings of powder coating versus liquid coating.

For our examples, I’m going to compare the amount of powder versus the amount of liquid paint to cover a 1’ square at a standard 2.5 mils. The mil, or thousandth of an inch .001, is most commonly used in engineering or manufacturing. It is used to specify the thickness of items such as paper, film, foil, wires, paint coatings, latex gloves, plastic sheeting, and fiber. (For example, most plastic ID Cards are about 30 mils in thickness.)

I’ll be calculating material costs using the coverage formula:

192.3 / Specific Gravity / Film Thickness = Coverage (Square feet per pound)

Let’s use a 1.4 specific gravity powder at 2.5 mils. The powder costs $4 a pound and we calculate our transfer efficiency at 70%. 192.3/1.4/2.5 = 55.2 coverage at 100% TE. 55.2 * 0.7 = 38.64. $4/38.64 = $0.10.

It costs $0.10 for a powder coated 1 square foot panel at 2.5 mils.  (For more info, Akzo Nobel has a great online calculator to do this at: http://www.interpon.us/our-coatings/powder-coverage-calculator/)

To get the same 2.5 mils DFT in a traditional liquid polyurethane, it will take a different calculation. Coverage is:

 ft2/U.S. Gallon = (%Solids/100 *1604)/ DFT (For a more comprehensive description of the liquid paint coverage formula: http://www.wellservicingmagazine.com/featured-articles/2007/11/applied-cost-a-useful-tool-in-paint-purchases/)

So to get 2.5 mils DFT with 45% solids polyurethane, 1 gallon can cover 289 square feet at 100% transfer efficiency. The average price for catalyzed polyurethane is $55, so at 50% transfer efficiency we get:289/2= 144 ft2 coverage and $55/144 = $0.38 paint cost per square foot. 

It costs $0.38 for a liquid coated 1 square foot panel at 2.5 mils.

Note these are only material costs. Liquid coating usually takes multiple passes and has much longer dry time. Flammability and waste disposal are also a concern for liquid coating operations.

In this example, the powder costs 3 times less. If a liquid coating operation uses $100,000 a year on paint costs, they can cut their paint expenditure by $50-60,000 being conservative. That difference is the price of a nice medium sized powder coating batch system.

Can I Use Liquid Paint Booths For Powder Application?

Powder coating equipment reliant finishing systemsWhile it is certainly possible it is definitely not recommended. Liquid booths are geared for a larger airflow pull than their powder equivalents. Too much airflow and you start pulling powder away from the part. This wastes money. Also, if you plan on continuing your liquid operation, you do not want to use powder and liquid in the same booth. It plugs up your filters fast and is a safety hazard if you are using solvent based liquid paint.

In future articles, I’ll be explaining more of the differences between liquid paint and powder coating, including specifics on transfer efficiency, waste, and energy savings. If you have any questions at all, or any topics you’d like me to cover, please e-mail me at bruce@reliantfinishingsystems.com

Looking for more information on powder, powder coating and application techniques? Please visit our growing list of articles on our Resources page.