Owners of cars and two-wheelers like to customize their vehicles, or even rebuild an old one that reminds them of their younger days. Much of the work involves painting, and that’s where problems arise.
A good finish requires a primer coat, a base coat to add color and a clear coat on top, or several of the above. These high-tech paints emit solvents that, if breathed directly, can be fatal. Leftover paint is a hazardous substance.
There’s a process that puts a gorgeous, tough finish on car, bicycle, motorcycle or boat parts, as well as patio furniture and whatever else is made of metal: powdercoating.
In the conventional paint process, liquid paint is sprayed in a “push” fashion, using air pressure.
Powdercoating, on the other hand, works in “pull” mode. After a part is sandblasted, an electrode is connected to it and builds an electrostatic charge. Dry powder is sprayed onto it, drawn into every place of the part and even around its back side.
It’s similar to the static cling you see when laundry comes out of the dryer. Due to the static attraction of the powder, there’s very little overspray, and it can even be collected and reused.
After the part is coated, it gets baked in an oven at 390 degrees. This makes the coating melt, producing a glaze that rivals the finest paint jobs, and is tougher than most paints. The powders are available in a huge variety of colors, standard and metallic.
From an environmental vantage point, this is a great solution. No solvent fumes go into the air. No exhaust fans are needed in the spray booth, which cuts down on HVAC losses.
There are no hazardous materials to dispose of. Unfortunately, you can’t drive the whole car into a powdercoating booth and get it coated. Only metal parts will take an electrostatic charge, and they must fit into the curing oven (which in some companies is huge, though).
Matching a color exactly can also be difficult, so some rebuilders will do the powdercoating first, and then match the paint of the other parts to the glazing.
Instead of using cheap spray-can paint that deteriorates quickly, or working with the hazards of professional car paint, it’s worthwhile to take those Mustang rims, or the bike frame, or the trailer hitch, to a local powdercoater. It will return with a shiny, tough coat lasting many years.
Rudi Kiefer, Ph.D., is a professor of physical science and director of sustainability at Brenau University.