John the stuff I was talking about is Dupli-color, Auto Spray Polypropylene Clear Primer. Dupli-Color # DS099
Now I could not find it on dupli-colors web page. I bought it at an auto paint supply place in Sioux Falls.
I did find it here under
DUP DS099
Anyway this is the stuff I told you about. I use it to prime my brass and aluminum and I also used it on my truck side rails (Trains now, not trucks) which are made of delrin plastic. I never had a problem with paint coming off of them with this stuff on it first.