So i just painted my headers a few weeks back they looked awesome and after the first time letting it run to fill up my new radiator the paint started to bubble and then flake off. I did everything as the instructions said sandblasted, cleaned with reduced kbs cleaner, dried with compressed air, 2 light coats of aerosol primer, waited about 10hrs or more then 2 light coats of pure white, baked in a welding rod oven at 350 for half hour. I even took the precaution of letting them sit for a week before i put them on the motor and only ran it for a few seconds 2 or three times to give it a good heat cycle before i actually ran it. Primer looks fine under the paint, should i have scuffed the primer? I included a before picture and will take a picture later of what it looks like now. 

This typically happens with the XTC Pure White because it goes on too thick trying to cover in one coat the color of the XTC Primer.

 

You can scuff the XTC Primer but that is not typically needed. The key is very thin coats with at least an hour between coats. If you cover in one coat the gray XTC Primer, you are probably too thick.

 

Please let us know if that helps and if you have any additional questions.

Ok i feel the coats were very light 1st coat didnt cover and 2nd was better but could still see primer faintly in some spots after 2nd coat. i used a small touch up gun with a 1.3 tip so i wouldnt dump a ton of material on it. Also i waited 8hrs between the coats white. Would it be better to sandblast then and start from scratch?

You can sandblast and start from scratch or scuff the XTC Primer that is cured. Either method will work great.

 

Last tip is to be sure to stir the XTC really well.

 

Please let us know if you have any other questions.

Ok i will see what sanding it to the primer looks like. Ill try 3 or 4 even lighter coats thankyou