[Mismatch77]

Hi guys I’m repainting my 1977 trans am. This is my first complete respray. I’ve sprayed primer and SS color on a few old cars and truck body panels just to make them match the existing paint before so I guess I know just enough to hurt myself.


The car I’m gonna be painting got a very poor extremely hard maaco paint job in the 80’s. Car was originally white, resprayed black. The paint cracks and snaps off. I’ve never seen anything like it. 200 grit with a electric Bosch orbital barely scratches it. I’ve been using 40 grit to knock it down to the white underneath. The top surface of the car looks like checkerboard from all the black popping off revealing the white underneath. Other than some poorly fixed body damage the original white paint seems to be in good condition on all the metal parts so I’m planning on shooting my primer over that.
The black paint seems like it didn’t actually stick to the white, and it’s so hard there’s no scratching or denting it it’s like porcelain. I’ve never seen anything like it.


My problem is the time has come to start sanding all the fiberglass pieces and I’m worried about mucking up their lines and edges. I’ll have to do them by hand I know and I have some hand sanders and 2 3/4 paper in 40 120 320 and 400. It’s possible to do this all by hand, but it’s gonna probably twice as long as the whole rest of the car and the chances of me sanding down an edge or contour are higher than I want them to be. I have a direct to fiberglass epoxy primer. And it wouldn’t bother me take them down to that fiberglass.

Is there any product I can use on the fiberglass parts to either soften the paint or strip it without damaging the fiberglass? Is that even possible?

For the rear tail light grills, and the side marker light grills I think they are a cast metal and any light duty stripper should clean them up I assume. Is that correct? The bumper on the seem to be in really good condition. I’ve got the whole car torn down right now.

[Formulabruce]

Sounds like the paint you are fighting is " IMRON " by Dupont. This stuff was developed for use in the commercial industry, like on Train engines. Have seen it on cars a few times.
The good part is that now its hard. It was developed to stay
Semi flexible and last. Because its hard it can more easily be blasted. So on the fiberglass parts have them media blasted.
You are correct on the stripper for the side marker lights. Once its close, dry them and then bead blast.
On your white paint. It is a polyester based lacquer and probably has micro cracks in it. They have to be gone!
Sorry you have to sand the black so much, you could use chemicals, but gotta get all the paint off to avoid contamination.
You could look into " Dustless" blasting.
Good luck

[Mismatch77]

I have a small blasting gun and a buddy has a professional wet or dry blasting set up. What media exactly?

I’m not sure on the Imron, i don’t think this is how it’s supposed to have turned out. It’s not flexible at all it’s like a shell. The edges all faded off, I think that checkerboard is from the car sitting outside in hale but there’s no dents just chunks of paint missing. The previous owner had Maaco spray it in the early 90’s then the car sat outside for a long period of time.


On the micro cracks, I’m getting the original white pretty thin, it’s probably 80 percent white paint with some expanses of steel and body filler. How would I go about making sure I got through all the micro cracks?

Almost every panel seems to have a some filler in it somewhere. And most of it looks well done. seems to still be adhering to the metal, and it’s smoothed and shaped well. The car didn’t have any rust really except the floorboards and the bottom edges of the fenders where rocks had chipped the paint down.

I wanted to blast it but after showing my friend he was scared that his blaster would either need to be turned down so low it’s not doing anything, or up so high to cut this weird paint it’d ruin all the filler and wear the edges of the car down. He owns his pressure washing, sand blasting business but he doesn’t do vehicles. I know he’s really doesn’t want to tear my car up.

[tjs72lemans]

Factory didn't use much filler if they had to at all. So, it must've been repainted the white at one time too. With that, and not knowing what's under it all, I wouldn't chance a new paint over an unknown old paint and bodywork. You may as well take it down to the metal or close to where you see factory primer. Same with your fiberglass. It's no fun, but you'll be ahead in the end with a lasting finish.

[Mismatch77]

I’d prefer to get the fiberglass bare. I don’t want to worry about building up to much primer/layers on the flats of the bumper if I sand through and edge of my primer and have to reshoot it, which I’m betting is gonna happen.


I figured the filler was applied before the black paint. The owner said the black went over the factory white, I don’t thijk he would have lied but he could have been mistaken.


The layers I’m seeing are the hard black metallicy top coat, a thin soft gray coat underneath, then a white coat I’m assuming is the factory white. I actually sanded a foot wide circle of just the white with 40,120,400,600 grit and it actually came out looking pretty nice for 5 min with an orbital. I already have a white 70’s vehicle or I’d have tried to save the white paint more and re shot it that color again.

What color is the factory primer supposed to be? There’s a light grey under the white but it’s very thin. Somewhere under the black but on top of the white is like a very light lime green. Almost like guide coat is layered in the gray primer.

[Old Goat 67]

Been there, done that.......

Aircraft stripper and then 3M Scotch-Brite pads down to bare metal.

[dataway]

I've had great success with the stripping disks in an angle grinder, haven't seen a paint it won't take off yet. If you use them be careful at the leaded factory seams, it will dig into the lead quickly.

In the early 80's I painted my GTO in a beautiful brown metallic Imron. Had the typical orange peel problems, but was industructible ... couldn't buff it though. Glad I removed it long ago enough that the pain has faded with time

[Mismatch77]

I can get the metal down bare I have many tools for that. I need to get the fiberglass bare without rubbing it for 3 weeks.

[TAKerry]

I agree that the best thing to do would be bring everything to bare metal. Including stripping off any old filler and redoing that as well.
What fibreglass parts are you talking about? The bumpers are a rubber'sh material and can be media blasted but you need to be careful and not be too aggressive. The only fibreglass I can think of would be the rear spoiler, the fender vents and the shaker. I would use a chemical stripper. I have done a few shakers with chemicals and sanding with no problem. For the spoiler and fender vents, if they have that much paint on them and chemical stripping doesnt work (but it should) I would get replacements.

[78w72]

best bet for the fiberglass parts & the plastic wheel flares & valance etc is to have them blasted with a soda media or other finer media like walnut shells if you can find a blaster that does that.

i had all those parts on my 78 & the more flexible rubber type wheel flares on my 81 blasted, stripped them all bare & didnt hurt the edges, but the blaster knew to be very gentle on those areas, reduce the air psi & hold the gun further away compared to doing metal parts as quick as possible.