>Any suggestions? What are powder coatings and is it expensive etc.?
>Happy New Year,
>Jim B. In Orchard Park, NY
The following is a definition I picked off a website somewhere, sorry to
post something this long to the whole list, but perhaps it will help
others. I was researching the issue myself because I intend to have my TD
chassis powder coated. As a matter of fact, I spent New Year's day
stripping off the chassis. I will let the list know about the results. I
haven't done any myself yet, but this is what others have said: Pros-- a
hard, smooth surface almost impossible to chip, no drips, no runs, no
errors, extremely consistent application (no thin or missed spots due to
electrostatic application), environmentally friendly because no solvents
are used. Cons-- If you get it where you don't want it, like in a
threaded hole (they mask these beforehand, but they might miss one) it is
very difficult to remove. It has the same hardness as paint and so it will
scratch about as easily. It goes on thicker than paint so be careful what
you get coated-- it might cause problems for things that require a close
tolerance.
Cost? I was quoted between $150 and $175 to do the chassis, including
sandblasting. The price list I got said about $40 for a wheel and between
$5 and $20 for smaller parts. When you consider paying for sandblasting,
epoxy primer, and paint separately (plus someone else's labor), it seems
very competitive.
Hope this helps. Here comes the definition:
What is Powder Coating?
Powder coating is an environmentally friendly alternative to solvent based
paints (and in some cases plating). The powder is made of dry, finely
ground organic resins and pigments. The powder is most commonly applied by
spraying with a gun that electrostatically charges the powder as it exits
the tip. In most cases, the powder is applied directly to a clean, bare
metal surface, with no primer or base coat (powder coating can also be
applied to glass, ceramics, temperature resistant plastics and even wood).
The part that is being coated is electrically grounded, causing the charged
powder to cling to it. After coating, the part with the loose powder
clinging to it is placed in an oven to cure. In the curing process, the
powder melts and flows over the surface of the object without drips, runs
or sags. The result is a highly durable and attractive finish in a wide
variety of colors, glosses and textures.
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Why Powder Coating?
Because of the need to reduce the introduction of air pollutants and
hazardous waste into the environment, a variety of alternative methods for
applying finishes to products are being developed. Chief among these new
methods is powder coating. Powder coating needs no VOC's (volatile organic
compounds) in any part of the process. This eliminates one of the major
causes of air pollution today. The most common coatings are made from
polyesters, urethanes or epoxies as a base. These are stable materials that
have extremely low or no volatile organic compounds. Powder coating is also
an economically attractive process. Because there are no volatiles, the air
in the work area does not have to be vented outside. This can offer
significant savings in heating and cooling costs. Also, with conventional
solvent based coating methods, overspray is wasted material. Powder
overspray on the other hand can be collected and reused, thereby achieving
95 percent and greater usage of materials.
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Where is Powder Coating being used?
Chances are you have quite a few things at home that have a powder coat
finish. It is used extensively on many consumer products such as
appliances, furniture, fixtures, automotive parts, sporting goods, etc.
Commercial applications include store fixtures and office furniture. It is
used on farm implements and in many industrial applications where
durability and high resistance to chemical and environmental stresses are
needed. Powder coating can also be an excellent choice for refinishing
projects such as bicycles, motorcycles, automotive parts, indoor and
outdoor metal furniture, etc.
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Preparing Your Project For Powder Coating
•The coated parts are cured in an oven at up to 450 degrees F, for up to 30
minutes or more. Any part of your project that cannot withstand this time
and temperature exposure must be removed before coating. This would include
foam insulation, rubber pads or gaskets and plastic pads or attachments.
•Because powder adheres electrostatically, it must be applied to a very
clean surface. It will not cling well to old paint, primer, most metal
fillers or rust. Chemical stripping and/or bead blasting of the surface is
recommended. Sand blasting with coarse media can leave a rough textured
surface that can show through the finish and in some cases cause gassing
that leaves pin holes. •Any welds, ripples, dents or pits on the metal
surface can show through the coating after the powder is cured. If you want
the finished surface to be free of these types of imperfections, they must
be smoothed or removed before the powder is applied.
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