Powder Coating Guide

Frequently Asked Questions On Powder Coating

What Is Powder Coating?

The powder coating process uses a solvent free dry mix of plastic resins, pigments and fillers that melt and fuse together when heated. The main difference between a conventional liquid paint and a powder coating is that, the powder coating does not require a solvent to keep the binder and filler parts in a liquid suspension form. The coating is typically applied electrostatically and is then cured under heat to allow it to flow and form a "skin." The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint. Powder coating is mainly used for coating of metals, such as "white goods", aluminium extrusions, and automobile and motorcycle parts. Newer technologies allow other materials, such as MDF (medium-density fibreboard), to be powder coated using different methods. The solid particles of coating are electrostatically charged in a spray gun and carried by low velocity air to the surface of the piece to be coated. The electrostatic charge holds the powder particles in place while the part is cured in a 200 degree C. The heat of the oven causes a chemical reaction to occur and the powder to cure, creating a highly durable finish

Why should I use Powder Coating?
Powder coated product simply looks better. It's more durable than liquid paint, more chip resistant, has superior adhesion, is less expensive than liquid paint of comparable performance, environmentally friendly, chemically resistant, and ready to use as soon as a part has cooled down.

What determines cost?
Number of pieces (piece cost decreases as the number of parts increases per batch), stripping required, masking required, color (non-stock colors are more expensive), texture, piece weight and maximum material thickness are the main factors affecting cost.

Do you handle small jobs?

What imperfections will Powder Coating cover up?
Powder coating can cover minor scratches and small imperfections. Smooth glossy powders are the most demanding and matte or textured powders the most forgiving for surface preparation. However, Powder Coating will not make up for poor workmanship. As with any coating, the end result is only as good as the surface it was applied on

Is it Environmentally Friendly?
Powder coating is an environmentally friendly process unlike solvent-based wet paint systems. With EPA regulations growing ever stricter, powder coating is fast becoming the technology of choice. Since the powder coating process does not use solvents in any way, VOC emission problems are eliminated

What Can Be Powder Coated?
Any metal object that can hold an electrostatic charge and withstand the heat of the curing process can be powder coated. Powder can be applied to intricate surfaces and still maintain a uniform finish across the entire piece. Powder coating is ideal for items such as:

  • Industrial Fabrications
  • Architectural Signage
  • Trade Show Exhibits
  • Metal Fencing and Railings
  • Retail Displays & Fixtures
  • Patio Furniture
  • Motorcycle Frames Wheels & Parts
  • Automotive Frames Wheels & Parts
  • Off Road Vehicle Frames & Parts
  • Bicycle Frames & Parts
  • Antique Beds, Gliders & Chairs
  • Large Bird Cages
How do you prepare parts for Powder Coating?
Surface must be perfectly clean, typically metal surface exposed with no contaminants. Oil must be thoroughly removed. MAX does this preparation for you. Before you bring the parts to us, please remove any rubber, plastics, gaskets, bearings, and other parts that are sensitive to 400° F temperature including excess oil and grease. For example, bring your rims without tires and valve stems.

What About Holes with Threads & Other Areas That Need To Stay Coating Free?
High temperature masking can be applied to special surfaces such as threads or high tolerance areas to keep them from being coated. We also use high temperature silicon plugs for threaded holes or shafts

Can I Use Body Filler?
The high oven temperature makes the use of plastic and resin body fillers problematic. Often the powder will not bind to a filler's surface causing bubbles in the coating. To be safe, fill any depressions with a torch using brass or welding rod as fill.

Is there a Powder Coating process that resembles chrome?
Yes, the powder coating "Near Chrome" is very comparable, however you lose the mirror effect with the finished product

What is Clear Powder Coating?
Clear powder coating serves the same purpose as clear coat wet paint. It protects the underlying finish and adds depth and luster to the surface. Clear powder coat is applied as a second coat and shot while the piece is still hot. Then the piece is returned to the oven for a second curing process. Use clear powder coating on any piece that exposure to elements could cause it to fade or be subject to damage.

Do we need a different pretreatment process for MILD STEEL, ALUMINIUM, GALVANIZED SHEETS & CASTING MATERIALS?

Yes,  we need to follow the different process for different metals, refer the attachment "PRETREATMENT FOR POWDER COATING.pdf" to know more in detail.

What are Advantages and disadvantages of powder coating?

There are several advantages of powder coating over conventional liquid coatings:

  • Powder coatings emit zero or near zero volatile organic compounds (VOC).
  • Powder coatings can produce much thicker coatings than conventional liquid coatings without running or sagging.
  • Powder coating overspray can be recycled and thus it is possible to achieve nearly 100% utilization of the coating.
  • Powder coating production lines produce less hazardous waste than conventional liquid coatings.
  • Capital equipment and operating costs for a powder line are generally less than for conventional liquid lines.
  • Powder coated items generally have fewer appearance differences between horizontally coated surfaces and vertically coated surfaces than liquid coated items.
  • A wide range of specialty effects are easily accomplished using powder coatings that would be impossible to achieve with other coating processes.

How long does Powder Coating typically last?

This is a very common question. From the perspective of adhesion and film integrity, correctly applied and pretreated powder coated metal can and has lasted since it was first applied more than 30 years ago.

Powder coatings are considered extremely resilient, be a coating of choice for use on gas or oil pipelines which are buried in the earth or underwater. Powder coatings are used on automotive and appliances given their excellent chip resistance, hardness and or chemical resistance.

From the perspective of resistance to light and UV degradation, some powder coatings are outstanding, being used on major building such as Duratec and Fluoroset FP.

The standard and most common powder coatings are designed for general use and applications. Standard powder coatings offer good weathering resistance, excellent film integrity and very good hardness.

How many Powder Coat colors are there?
There are about 100 different colors on a regular basis, but there are several thousand available . And, if money is no object, there is no limit to what’s available.
In addition to the different colors and shades, Powder Coat is available in several “Finish Types”. They are classied as Texture (aka Hammertone), Metallic (like metal flake it comes in several sizes of “Flakes” from large to micro), Solid, Translucent (aka ‘Candy’) and Clear (actually a Clear Translucent). and a fairly new one known as “Chrome”.

Can powder coatings be applied on site?
Powder Coatings are a factory applied finish using specialized equipment. The equipment includes an electrostatic spray gun, spray booth and an oven to bake (or cure) the coating. On site application is not possible given the hot curing cycle required to fuse the coating.

The Future of Powder Coating?
In addition to successfully penetrating the MDF (medium density fiberboard) market, powder has proven to be an effective finishing choice for other heat sensitive substrates such as plastic parts made of nylon and polycarbonate and assembled or partially assembled products such as appliances, electric motors or automotive radiators. Because of advancements in low temperature cure powders, plastic parts and wires and rubber seals and gaskets are not damaged in the powder coating process.

And the revolution has just begun. Successful testing has occurred on hardwoods such as beech, oak, ash and walnut. Research engineers are studying the use of powder on paper-laminated MDF, laminated flooring and particleboard. Research is also being conducted on counter tops, wood molding and trim, all of which will increase demand for, and use of, powder coatings in more new markets

Do we need to follow different troubleshooting guide for different powders?

Yes, it is good to follow the powder manufacturers trouble sheeting guide to get better results and to be trouble free powder coating, refer the attached trouble shooting guide from the respective manufacturers.

What is "out gassing"?

Out gassing is the release of gasses that are trapped in the cast metal when the coated part is cured.  This leaves bubbles in the powder coated surface. MAX Surface Coatings will process all cast iron or aluminum parts to minimize out gassing.  The chances of out gassing are greatest in old aluminum or inexpensive castings.

Can you powder coat my frame in two different colors ?

Yes, but the process is more involved and requires not only a color change, 2 rounds of masking, partial curing, and very tedious clean up of the frame between colors. For this reason, the cost is added doubled depends on the masking complexities.

Can we do "powder coating on Stainless Steel Components" [powder coating on SS material]?

Yes, we can do powder coating on stainless steel components with special pre-treatment process.

Will Powder Coating cover flaws in materials?

Small scratches and minor flaws can easily be masked by the Powder Coating process. We can help you choose more forgiving powders based on the condition of the surface.

Question: Should I have my parts sandblasted before bringing them to you for powder coating?

Answer: You can have your part sandblasted before you bring it to us, however we do not recommend it. After a part is sandblasted it is bare and exposed to the elements. Any moisture in the air will cause your part to begin surface rusting. Although this may not be very noticeable to the naked eye, it will be present. The presence of this microscopic surface rust will compromise the adhesion of the powder. For this reason, we cannot guarantee the adhesion of the powder on any parts/components that are sandblasted and storied outside for a while before it is transported to us for powder coating.

Muthu G,
Mar 11, 2011, 7:08 AM
Muthu G,
Dec 7, 2010, 6:25 PM
Muthu G,
Mar 10, 2011, 10:44 PM
Muthu G,
Mar 10, 2011, 10:45 PM
Muthu G,
Mar 11, 2011, 7:02 AM