Can you paint over worn powder coating? Absolutely yes you can. I had searched this thread and a number of other forums regarding whether it is possible to paint over powder coating. Some members said yes and others no.
I had an issue with brand new powder coating discoloring on the bottom muffler after it had been powder coating over the stock chrome Screamin Eagle slip on mufflers.
I then bought the Rustoleum 2000F Primer rattle can and the Rustoleum 2000F black mat rattle can from the local hardware store.
I sanded the bottom muffler which had the problem of discoloring with 220 grit sandpaper. The top muffler had no issue and I didn't sand this muffler.
I laid down about 3 - 4 primer coats down on both mufflers and then left for 1 day to cure. Next day I laid down 3 - 4 coats of the black mat rattle can spray, and then shoved them both into the oven to cure as per the instructions on the cans.
Fitted them to my Street Bob the next day and then took it for a 20 minute ride. Result. No discoloring and came out great! Works well but have to be patient and follow the instructions to the t. I will post some fotos.

 

I wonder if this will work on ceramic coated pipes also?

 

Yes sure. More so for ceramic paint than powder coating because powder coating is in essence made of fine plastic particles. Ceramic coating is more tightly bonded together and this will form an excellent base for painting with this 2000F heat spray. I would still sand lightly to provide a rough base surface and then apply the 2000F heat primer with a few coats before applying the main coat.

I have taken my Street Bob out for a couple hours ride after painting and the paint still reflects like when it was first painted. I have been very impressed with the Rustoleum Heat paint.

 

nice one!

I just found the answer the question that i have on my mind.

 

As long as the chemistry (molecules, protons and morons) have somewhere to adhere to it can be put on there.. I just like to say Moron...