I'm changing my gray ground effects on my 87 Fiero to medium red like the rest of the car, When I was prepping the parts I sanded through to the raw plastic in places. Do you think epoxy primer will stick to those spots if I coat the whole part? Should I use plastic primer to spot prime the sanded spots before I spray on the epoxy primer? I really don't want to do this again so I need some experienced folks advice.
primer is made for paint to stick to it , you want the best long life paint job primer all places that need it a rattle spray can paint job works better with primer you sand all paint you will be painting over to remove dirt,wax,top level which is damaged much worse than the lower level of the pint,primer any places you sand thru
I have block sanded all the surfaces. I am going to prime everything with epoxy primer. What I am wondering is if I should spot prime raw plastic areas with plastic primer before covering with epoxy primer? I'm not sure if the epoxy primer is going to stick to raw plastic?
There should be a three letter code molded in the back of the parts. Some of them are ABS, which will take paint with no special treatment, or the plastic could be TPO, which should have plastic primer.
A good epoxy should stick well to the sanded factory pieces. I use PPG DP epoxy primer. Cheaper ones have given me problems in the past - don't know how well they stick to plastic... Plastic primer is really for use on bare hard plastic like interior parts. HTH, ~ Paul aka "Tha Driver"
The issue with sanding old paint is that contamination is at a molecular level, so the impurities like wax can still be there and cause fish eyes.
I always wipe it down with lacquer thinner and sand again.
I do not subscribe to the notion that you need the more expensive epoxy primer for what are plastic parts. Standard primer works perfectly well.
I have used urethane but I don't like it for a home paint job. I prefer lacquer for home use, due to the ease of use and absence of the chemicals requiring a full respirator rig. It also has a fast flash over point, when you don't have the luxury of a drying booth.
Most OEM plastic parts I get come with an instructions label for painting stuck on them. I cant remember the last time I saw one that said to use any primer at all. ABS for example has always been recommended to just be painted with no primer for best results. All the bumper covers I get for Jag and BMW recommends no primer. I will primer a plastic part if its got old paint featheredged, or some minor scratches to fill. If I do have to put some primer on a part for that, any automotive primer is fine. I use lacquer, but many use catalyzed primers. Plastic bumpers on all new cars are not primered...at least none Ive worked on. Factory puts basecoat right on the bare plastic. Urathane (basicly rubber flexible type) bumpers usually come with a waterbased primer already applied. So on your lower skirts, since theyve been painted and sanded, I would put a light coat of primer on of your choice. Just DONT use any kind of an enamel primer. Ive run my own shop for 40 years.
