Everything you wanted to know about powder coating!
What is Powder Coating?
So, you've heard of it, but, you're not quite sure exactly what powder
coating is. According to the Powder Coating Institute's web page, "Powder
coating is an advanced method of applying a decorative and protective finish
to a wide range of materials and products that are used by both industries
and consumers. The powder used for the process is a mixture of finely ground
particles of pigment and resin, which is sprayed onto a surface to be coated.
The charged powder particles adhere to the electrically grounded surfaces
until heated and fused into a smooth coating in a curing oven. The result
is a uniform, durable, high-quality, and attractive finish." There,
so now you know! Or do you?
The Eastwood Company offers a HotCoat Deluxe Kit , that like most powder coating guns, applies a negative electrostatic
charge to the flour-fine powder (that magical mixture of "pigment
and resin"). This charge is high voltage; up to 25,000 volts (100,000
volts on industrial guns), but fortunately very low amperage (the amps
are the part of electricity that can really hurt you). Since this powder
is made of resins, it falls under the general classification of "plastics."
As a member of the plastic family, it is a poor conductor of electricity.
So once the particle is charged, it gives up that charge very reluctantly.
This is what causes the powder to "cling" to the substrate being
coated. The negative ions in the particle slowly fight their way to the
positively charged substrate. This slow flow of ions from particle to substrate
is what holds the particle on the substrate. Putting it another way, think
of the positively charged substrate as "sucking" the negative
ions out of the particles, causing them to stick.
Why Is Powder Coating Better?
- More Durable—Powder coating gives consumers, businesses, and industry one of
the most economical, longest-lasting, and most color-durable quality finishes
available. Powder coated surfaces are more resistant to chipping, scratching,
fading, and wearing than other finishes. Color selection is virtually unlimited
with high and low gloss, metallic, and clear finishes available. Thanks
to the UV resistance of many of the powders, colors stay bright and vibrant
longer. Texture selections range from smooth surfaces to a wrinkled or
matte finish, and rough textures designed for hiding surface imperfections.
- Protects the Environment—Powder coating is also highly protective of our environment. While
liquid finishes contain solvents which have pollutants known as volatile
organic compounds (VOCs), powder coating contains no solvents and releases
negligible amounts, if any, of VOCs into the atmosphere. Thus, there is
no longer a need for finishers to buy costly pollution control equipment.
In addition, most powder coating overspray that does not adhere to the
part can be retrieved and reused. Although this is not always practical
for many low-volume users, this can virtually eliminate the waste commonly
found in liquid finishing processes.
- Saves Money—Elimination of VOCs and reduction of wastes saves money and helps
companies comply more easily and economically with the regulations of the
U.S. Environmental Protection Agency. In fact, one of the major elements
in expanding the market for powder coating has been the implementation
over the past 30 years of stringent air pollution control legislation.
Where Is Powder Coating Used?
- Appliances—The appliance industry benefits from powder coating on front and
side panels of ranges and refrigerators, washer tops and lids, dryer drums,
air-conditioner cabinets, water heaters, dishwasher racks, and cavities
of microwave ovens. Powder coating has also replaced porcelain enamel on
many washer and dryer parts.
- Architecture/Building—The architectural and building market powder coats aluminum extrusions
used on frames for windows and doors and modular furniture. Many highway
and building projects use powder coating on light poles, guard rails, signs,
posts, and fencing.
- Automotive—Henry Ford once said, "You can have a Model T in any color
you want. So long as it's black." For an industry once focused primarily
on manufacturers' needs, powder coating is transforming the automotive
industry with faster production times and lower operating costs, plus irresistible
value propositions for consumers. For years, conventional liquid coatings
were the standard for the automotive industry. But these coatings can emit
dangerous VOCs at their application stage. Powder coatings eliminate most
environmental concerns and the need for costly waste disposal systems.
Because powder does not run or drip, the result is a uniform, superior-quality
finish.
Conversion from liquid to powder clearcoats for auto body exteriors is
moving rapidly. Powder topcoats resist acid rain, the sun's ultraviolet
rays and road and weather damage, helping cars retain their "showroom
look" much longer and improving their resale value. BMW and Volvo
are using it on their new model cars, and GM, Ford, and Chrysler have formed
a consortium to test this technique on their production lines.
Powder coating has made substantial inroads as a primer for car, van and
pickup truck bodies in the United States. Auto body primers in colors will
be next.
There is huge market potential for high-heat resistant powder coatings
on aftermarket mufflers, which resist corrosion, protect against nicks
and prolong the life of the muffler. Some companies are already applying
heat-resistant powder to aftermarket mufflers, and the new-car market is
thought to be two or three years away. Powder coating is also applied to
wheels, grilles, bumpers, door handles, roof racks and exterior and interior
trim. "Under the hood" uses include oil and fuel filters, brake
pads, engine block casings, suspension components and radiators. Pickup
truck and SUV owners can purchase powder coated side steps, bed rails,
luggage racks and toolboxes as dealership add-ons or in aftermarket stores
and catalogs.
Performance car owners can find powder coated special suspension units,
carburetor parts and valve covers, plus flashy rear-view mirror mounts
and other exterior adornments.
Everyday Products
There are also innumerable everyday uses for powder coated products such
as lighting fixtures, antennas, and electrical components. Farmers have
powder coated tractors and farm equipment. Fitness buffs powder coat golf
clubs and golf carts, ski poles and bindings, snowmobiles, bicycles, and
exercise equipment. Shop owners have powder coated display racks, shelves,
store fixtures, and vending machines. Office workers use metal furniture,
computer cabinets, mechanical pencils and pens, thumbtacks, and other desk
accessories that are powder coated. Parents have powder coated baby strollers,
cribs, metal toys, and wagons. And home owners have lawn mowers, snow blowers,
barbecue grills, patio furniture, garden tools, electronic components,
bathroom scales, tool boxes, and fire extinguishers which benefit from
a powder coated finish. The powder coating boom has just begun—expect
more exciting uses in the near future.
Shopping Links:
  The Eastwood Company's HotCoat Elite Kit (left)
The Eastwood Company's Powder Coating Chip Chart
Eastwood's Beginning Powder Coater's Handbook
The HotCoat Elite Kit (shown at left) includes everything you need to begin
powder coating immediately. (You will need an oven and compressed air as
well.)
You can achieve professional results at home, and save a ton of money doing
it yourself!
Just click on the image to buy directly from The Eastwood Company.
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