Best Machinery Painting Method

Q. I have a forklift manufacturing shop and searched many years for the best and most economical way of painting this equipment, and finally came to the following method with which I am pleased so far: 

 

1. Clean the metal parts with a phosphatizing, rust removing, oil solvent solution applied with a brush, keeping the material on long enough to be wet for at least three minutes. It is recommended by our supplier to be immersed.
2. Once dry, rub with a cloth wet with this same solution to remove some fine powder which forms on the surface.
3. Now we apply epoxy paint directly with a spray gun, without any primer.

 

It is a very economical way of finishing low volume big metal parts and found that the paint grabs very well to the surface. We put it to test for months in the open and under the rain with no rusting. We try to scratch it and it holds better than the primer-enamel system we used before. So there is no use of thinner, we save the time used in priming, it dries (cures) faster, holds better, and it has a more pleasing finish.

 

1. Am I using the right method?
2. Why nobody else is using it as far as I know?
3. Can I improve the cost and/or quality? E. E.

 

A. The answer to question one, if you are pleased and your customers are satisfied with your finish quality, stick with it. By your account, it seems to be working. I don’t know the answer to question two. To answer question three, I would rather see another cleaning step in your process. By using a precleaner, you may extend the life of your, more expensive, pretreatment chemicals, which you describe as a phosphatizing, rust removing, oil solvent solution. Despite the fact that you are brushing and not immersing in your pretreatment, it can still become contaminated with oily soils, decreasing its effectiveness. Therefore, it must be dumped frequently. The use of a precleaner will ultimately lower your finishing costs.