Q. How can we rework scratches or other surface imperfections in a powder-coated finish? I need a step-by-step process in order to make a list of instructions for the rework procedure for my operator.—F.S.
A. This is somewhat difficult to answer in a simple fashion, but I will do my best to give you the basics and be brief.
- All loose material must be removed by wire brush, sanding or similar method.
- All rough areas should be smoothed with sand paper or a grinder.
- All dust and dirt must be blown off or washed off.
- The part must be dry and free of all debris prior to coating.
You will need to recoat the entire part with the powder spray so that none of the original coating shows through. For optimum coverage, adjust the gun settings to reduce the amperage to around 20 micro-amps and increase the flow rate of the powder by about 10 percent. Hold the gun a little farther away from the part, about 1” to 2” more than normal. Finally, cure the part for the normal cure cycle. This process should work well for you. Practice on some scrap parts to perfect your technique.