Where to begin restoring plastic 1972 RR center grille?

[Dibbons]

The center section of this grille is peppered with blisters and craters. Looks like it was painted black. Is it safe to just sand it down smooth? Does the surface need to be "rebuilt" before repainting? What caused it to become so ugly in the first place? Thank you.

 

[flypaper]

that looks like it was painted at one time and it is now lifting.
there are a few ways you could go...

if it was me,before going nuts sanding,
i would first try a special paint stripper they have
that is used for corvettes.
regular paint stripper will destroy the fiberglass panels on those cars
i have had great luck using it on plastic/fiberglass parts/grilles and such
most good autobody suppy stores will carry it.
as always, test a small area first before going crazy with it.
i'm sure now someone will say brake fluid or oven cleaner..lol

 

[Seventy]

I hate to say it but I would just start with a paint stick wrapped with 180 until all the loose paint and chips are gone, then switch to 220 until the surface is uniform, then blow it all off, the surface should be nice and uniform with no bumps or anything you can feel with your bare hands.

So after its all washed off and dried, I would wipe with a tack cloth and spray it with a urethane primer either sem or the spray max rattle car has worked well for me also although its expensive.

When I use the spray 2000 urethane, I dust the first coat very light, wait 5 minutes the lay on another coat a bit heavier then about 2 more coats with 7-10 minutes between them, you want some build there so you have something to wet sand...

After I let the primer dry for a few hours I put on a guide coat {black rattle can or any color for that matter as long as it contrasts with your primer}, after that dries I start with 600 grit {wet}, start sanding and see if you have any high spots, if you do after you pass the 600 over the flat part of the grille you will still see the guide coat, if it all looks even, just sand it up with the wet 600 until your guide coat is all gone and there is just primer left.

wash it down with pre wash (wax and grease remover), let it dry, tack cloth it again, then shoot it with your paint, pick a black that looks like the factory color and start with light coats giving time between each. Seems most mopar grilles are flat colored, I like to clear coat grilles but doing this and keeping a matte finish is tough, sem makes a nice kit called "hot rod" black, I have painted a few motorcycles with that works very well BUT its expensive, choose a good rattle can and I am sure it will look fine for a bunch of years...

 

[Dibbons]

If I were to begin with the 180 as suggested above, is wet or dry sanding recommended?

 

[Seventy]

If I were to begin with the 180 as suggested above, is wet or dry sanding recommended?

first dry, just to remove any loose material and get through the top coats that are going to be completely removed, no need for a ton of pressure, just blow everything off there by hand, it may take an hour but you can see everything that is happening nice and slow... I do it this way because I am not a pro body man, pro's can preidict what a panel is going to do because they do it all day, so they may throw 80 grit on a DA and go to town for 1 minutes then 320 and then wet sand it with 400/600 etc, I would hate to ruin a part I just had shipped in or would have to ship in a replacement so I tend to go slow and take my time.

I restored 70 charger tail lights tonight, started at lunch time & just finished, lol. I did go in the pool when my kids got home, ate lunch, dinner, had a beer or 4, etc but I truthfully spent 8-9 hours on them and they were already taken apart before I started.

I Bead blasted the buckets and hardware (mice were living in them for a while), washed them, primed them, then cleaned the lenses, touched up the black with VHT nite shade paint, while that dried I wet sanded the buckets, rehung them, and gave them their first coat of paint (it was 80's earlier so everything was drying nicely), then another coat of tint on the lenses, then back to the buckets, I finished painting the buckets, took a break, by the time I got back to them everything was dry, I polished the unpainted portion of the lenses, checked the buckets out and painted the hardware up (screw heads}, another brake and I put them all back together. When I was younger I would have been itching to finish them in an hour, now I dont mind spending a day on a pair of taillights, I am home anyway...

Anyway go slow enjoy the restoration..