True as oldokie says, I've never been to a Powder Coater that didn't blast the old paint (and other crud) first thing, a reputable PCer would not apply coating over anything but clean bare metal or fillers that he knows will take the heat, otherwise he does the job twice. The thick nature of PC can hide surface defects, but also hides details you might WANT to see...paint can be applied thinner, usually costs more. I had one PCer offer to sand and apply MORE PC to even-up a finish he thought was too bumpy, that was a new one to me as I didn't know one could add layers with PC...it came out fine and smooth.