[dsraven]

on an oil pan or other steel sheet metal stuff I have had good luck cleaning parts with oven cleaner to get rid of anything that will limit paint adhesion. super clean from castrol is another good degreaser but some products that degrease well aften leave a residue that needs to be removed after before painting. another thing I have done is to heat the steel a bit with a propane torch to see if anything other than condesnsation comes to the surface. that trick works pretty good for aluminum stuff as oven cleaner and aluminum are not the best of friends. then the wax and grease remover and a clean rag to wipe that off. even the rags tough, I find if the wife has laundered my dirty rags she has used an anti static sheet in the dryer to "help them smell better" and then they have some kind of stuff in them that must get on the surface when wiping and the paint won't stick there. I use paper towels with the wax and grease remover or some painting rags that I buy as paper towels tend to leave their own little fluff tags behind if the surface isn't really smooth. sometimes on little things I will spray some gun cleaner on the part and simply blow dry before painting. i always leave a bit of time after doing that or wax and grease remover so the parts are actually dried off. spraying too soon after the wipe down can sometimes show where the wiping rags were used so the solvents must not have totally dried. that causes craters, nobody likes those after all that prep work.