Adhesion promoter

[GJSZ51]

I am building my second Harley and all the parts on thus one are plastic or fiber glass. My first one, a deuce, was all metal. The quality of the plastic molded pieces and fiberglass parts are excellent quality but, to insure maximum adhesion I have used the promoter. I applied 3 coats of black epoxy and will be moving on to sanding and blocking in the next couple of days. Usually I block until I "break through" to achieve surface uniformity and straightness. If/when I break through, will I need to reapply the adhesion promoter prior to application of more epoxy or, if straight, applying epoxy sealer coat prior to base?

 

[texasking]

Just a light coat of promoter on the bare spots. I use a touch up gun to keep the areas sprayed small. I would recommend straight epoxy (1:1) over bare spots.

 

[metalman]

Not sure the adhesion promoter was necessary. What type of plastic were the plastic parts? Any code imprinted on the back sides? I thought they used ABS ( not 100% positive) and epoxy sticks very good and probably better without the ad pro.