Fiberglass stain or ??? removal

[Mufasta]

I have a 1992 Class A that is badly stained or whatever. The stains are mainly around the windows. Looks like the streaks that occur when you clean window with a squiggy (sp?) and the dirty water runs down. As far as I know the rig sat for at least 5 years, but under what conditions I do not know.

Standard cleaners did nothing. Zip. Awesome, bleach, Simple Green, and every black streak cleaner didn't dent it. Nothing.

Ajax helped some. The problem is it did nothing for the dark parts but made the white britter. In some ways made it look worse. Letting it sit as a paste.

Mr. Clean erasure did nothing.

A fiberglass cleaner and wax (Gel something) from Home Depot did nothing.

Light rubbing compound did nothing.

Heavy rubbing compound by hand did nothing. When attached to a 7" polisher it started to take it away, but not all of it.

Maguires #67 heavy duty fiberglass cleaner did nothing. Even on the polisher.

1500 grit sandpaper worked only if I was focused on a 1/8 inch area. And even then it took a while.

Davis SSR Fiberglass Stain Remover which I got from a boat place helped some. But again not on the dark areas.

This is driving me crazy. It makes the rig look very unkept. Like I just need to wash it but won't. I almost don't care about damaging the gel coat since it looks terrible already.

One more thing. Sometimes I don't know if it's a stain or not. The reason is it doesn't come off uniformly or in shades (dark to light) It almost seems that some areas (the real bad, dark areas) have a very hard "crust". I keep thinking eggs were thrown over the whole rig, got dirty, and then sat in the desert sun for a whole summer. When I polish with the compound it starts to come off but little specks (1/16 to 1/18 of an inch) and sections are left. The 1500 grit sandpaper can take those areas off but I'm focused on one very small area. This way will not work for the whole rig.
I'm very tempted to use something like acetone or sulfamic acid on a small back section just to see what happens. Of course I would only work it on small areas to keep it under control (and away from decals or pin stripping), but would it damage the gel coat?

Any additional ideas would be appreciated! Thanks.

[Mufasta]

I have a 1992 Class A that is badly stained or whatever. The stains are mainly around the windows. Looks like the streaks that occur when you clean window with a squiggy (sp?) and the dirty water runs down. As far as I know the rig sat for at least 5 years, but under what conditions I do not know.

Standard cleaners did nothing. Zip. Awesome, bleach, Simple Green, and every black streak cleaner didn't dent it. Nothing.

Ajax helped some. The problem is it did nothing for the dark parts but made the white britter. In some ways made it look worse. Letting it sit as a paste.

Mr. Clean erasure did nothing.

A fiberglass cleaner and wax (Gel something) from Home Depot did nothing.

Light rubbing compound did nothing.

Heavy rubbing compound by hand did nothing. When attached to a 7" polisher it started to take it away, but not all of it.

Maguires #67 heavy duty fiberglass cleaner did nothing. Even on the polisher.

1500 grit sandpaper worked only if I was focused on a 1/8 inch area. And even then it took a while.

Davis SSR Fiberglass Stain Remover which I got from a boat place helped some. But again not on the dark areas.

This is driving me crazy. It makes the rig look very unkept. Like I just need to wash it but won't. I almost don't care about damaging the gel coat since it looks terrible already.

One more thing. Sometimes I don't know if it's a stain or not. The reason is it doesn't come off uniformly or in shades (dark to light) It almost seems that some areas (the real bad, dark areas) have a very hard "crust". I keep thinking eggs were thrown over the whole rig, got dirty, and then sat in the desert sun for a whole summer. When I polish with the compound it starts to come off but little specks (1/16 to 1/18 of an inch) and sections are left. The 1500 grit sandpaper can take those areas off but I'm focused on one very small area. This way will not work for the whole rig.
I'm very tempted to use something like acetone or sulfamic acid on a small back section just to see what happens. Of course I would only work it on small areas to keep it under control (and away from decals or pin stripping), but would it damage the gel coat?

Any additional ideas would be appreciated! Thanks.

[Ray,IN]

It sounds like you've tried everything marketed and most home-brew recipes. I think that is pollution settled/washed out of the air. You might get some advice from a large boat repair facility. They deal with gelcoat daily.

[cvrvr]

3M make a product called "Adhesive, Wax, and Mark Remover". It has taken some nasty marks off the gelcoat on my coach.

One thing, after you apply it, there is NO wax left on the surface.

George

[Digital Boy]

Have you considered a new paint job?