Wanting to know peoples experience with mixing different brands or lines of paints. Ie putting a chroma premier over a Nason series (all Du Pont). Or putting a dupont color over a different brand primer. I spoke with people at the local automotive paint shop who said they would not adhere well and would run or flake off of each other. How much truth is there to this?

 

it does hold truth. I'm used to using BASF products (diamont line) and have heard many stories about adhesion from different primers / sealers / clears etc... however, i was doing a project of my own, and by project i mean a bumper cover and not a whole car thank god. Anyways, I had sanded, feather edged, and spot puttied the cover and realized i didnt have any primer left, so my buddy let me use his ppg line of primer, however, I had diamont base/clear. whatever, so i sprayed the primer, let it flash and cure, sanded it and applied my base coat and clear coat and let it sit after i was finished spraying. come back an hour later and the whole thing had lifted...ALWAYS follow product specs...

 

Many people leave the original paint on the car and just sand it down to a goo d finish. Primer over it and then paint and clear. These are usually different paint brands and lines, which is why I wonder why it is a "bad idea." I don't doubt any body's experience. but why can you primer over old paint and be ok but not a diferent line of primer or paint?