I am building a 73 plymouth satellite custom wagon! The plastic in the rear of the car is pitted, scratched, and faded. I am not going original with the car so any ways I can repair this is ok but I'm trying to figure out the best way the smooth it back out and paint it. Any help would be greatly appreciated!!!
The plastic formulations they used back then were not very good for longevity, but you should hit up sites selling I terior parts; you may be able to score some good-condition parts you can paint or dye to match your rig. There really is not much you can do with plastic resto if heat has broken down the polymer chains. If the surface is only affected and has a dust layer, clean the piece with warm water, detergent and a soft-bristled brush. See if that will bring back the surface detail, and if it does, then spray with a satin clear coating to help it look better and possibly protect it from deteriorating further. Otherwise, take a look to find what you can to replace your parts.
I've used 2 part flexible plastic bumper filler on the pieces like that, it gives a little and sticks to anything. Then sand it smooth, plastic adhesion promoter, SEM plastic paint to match the interior. I use satin or semi-gloss clear lacquer over the SEM to give it a little more gloss and durability. If it's flexible plastic you can practically eliminate a lot of surface scratches and little nicks by very quickly just licking the surface with a mini-torch flame, a paint stripper gun works too. You have to be real careful not to melt the surface in either case.
I agree with BV. It's amazing what you can do with some of todays compounds. A full "sealing" on the plastic piece can extend it's life a long time while you look for replacements. Don't forget your local vinyl wrap shop, they can cover almost anything with a wood grain, carbon fiber, stainless look. Shutterstock.com has thousands of ideas.
