Old Paint Problems

[Gray14]

Can anyone tell me what the cause of the paint problem I have.

When I bought it 2 years ago it had only a couple of paint blemishes that I took to be ‘Fisheye’.

The front and rear are now completely covered in 1-2 mm spots where the edges are lifting away from the surface.

In places the paint has flaked off completely. I feather edged these yesterday for repainting and found a couple of more paint chips had broken off from the feathering this morning.

The paint layer is very thin and it doesn’t take much rubbing down to get to the GRP surface. Could it be the original factory applied paint breaking down.

I put a car cover over it over winter but it seemed to deteriorate just the same.

I think I read someone else having the same issue about a year ago.

Can anyone suggest what the cause might be.

Thanks G.

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[TAR]

I believe the small spots could be moisture escaping from the body. It's important that the fiberglass is completely dry before painting.

[supraholic]

Hard to tell from the pictures, but it kinda looks like it might have been repainted once before. Looks like white paint is flaking off and there's another layer of white underneath. I'm still a newby to the Lotus, but on Corvettes, I do know that the back side of the fiberglass panels were not gelcoated and will absorb oils, greases and solvents (I kinda cringed on that recent video when they were spraying WD-40 in the lock cylinders and on the door hinges of that red Excel - hope that doesn't cause problems later). If the fiberglass gets compromised on the back side, stuff can soak in and cause the paint to come loose from the surface. Typically you'll see bubbles on the hood at the front of the motor where the pulleys have slung whatever leaked out (mineral oil from the air conditioning compressor, power steering fluid, etc.). But this doesn't look like that kind of pattern.

These Excels for a long time weren't worth hardly anything, certainly not worth what it cost to repaint one and do it correctly. Just guessing, but could it have gotten a "low budget", minimal prep kind of paint job sometime in the past? I don't know if you have Earl Scheib or Maaco chain of body shops over there, but we have these here that used to advertise on TV that they would paint any car for like $399 (when I was a kid in the 80s, I remember it was just $99 and my dad remembers when it was $29). They'd wash it, scuff it, mask off the windows and trim, then spray it in one of about a dozen colors (no color match at that price), then bake the whole car in their oven to dry. Those cheap paint jobs didn't last long, looked worse than ever in only a few years, then cost twice as much to do it over again correctly because there would be extra cost to chemically strip the "new" paint or in the case of fiberglass, sand the whole thing back down to the base or gel coat.

I've done body work but lots of times my painter would point out my sanding mistakes, stuff that I couldn't see but that he said would be visible through the new paint. He'd always have to touch up a bunch of my body work so I've always kept it to just the major rust and collision repair and left all the surface prep to the professionals. I wouldn't sand on it anymore until you talk to a professional paint and body person because you might just be making extra work for them.

[Lotus-e-Clan]

Water vapour within the compressed air when last resprayed, or sprayed in a damp environment / on a damp day is my guess. Wet compressed air is most likely imho.

[Alan_M]

Could all be microblister that you’ve sanded the tops off. Keeping the car with a cover over it in the winter is one of the best ways to cause that.
Looking at that, I would say if you want the next paint job to last you will need to sand all that off. Do not wet sand, use net type abrasive and sand dry. Any moisture than gets trapped in the fibreglass can later appear as microblister.
Once sanded, use a 2K epoxy primer to seal the surface.
Also those areas you have sanded, the edges need to be feathered back more or there is a very good chance they will show through.

[Gray14]

Thanks for the replies. Sprayed on some etch primer today and noticed lots of micro / pin prick size holes where the paint had blistered.

The paint is also very brittle and easily chipped.

Put on some stopper, rubbed down, reprimed and it was looking better.

[Alan_M]

Etch primer is for metal, not GRP, use 2k epoxy primer.
If you get any fry up, use Barcoat to seal the surface, but if you’re wanting paint to last make sure you remove ALL paint that is not 100% solid.