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truckin · 02-16-2015, 11:58 PM

The 2001 MH I bought had sun damaged faded decals with a portion of them sun baked/cracked. I was going to remove them and blend out the ghosting and just repaint the sun faded basement paint.

That was until I saw one section that was obviously getting a lot of sun had a lot of thermal crazing under the dark decals. It is not affected on the plain gelcoat or the light decals. It is the fine spider cracks like alligatoring where you can feel the ridges on the crack. These are traditional fiberglass panels (luan?), not filon.

I want to see if there are success stories on repair out there as opposed to replacing the panels. I can't replace the panels, so it is repair for me, but the scope of what I put into it will be based on the success or lack there of that others have had firsthand. The need to repair isn't to get the best ascetic result or even last a lifetime, but just to seal the cracks and hopefully impede the spread of existing ones.

I have heard what seems to be a couple same stories oft repeated about failed repainting so I'm trying to get an idea on just how large the sample size is of failed repairs before I totally write it off, and the method.

I had little doubt that a simple repaint won't fail over time, but were those jobs just a sand, primer and spray? Or, were they done like hull repairs that do tend to last were they were ground out, resin filled and then primered and sprayed?

I've done similar thermal crack repairs that seemed to hold up on a boat. The other thing is since the glass is perfect everywhere except under dark decals It leads me to believe by repainting in white and using sparingly light color accents I run little risk of developing new cracks. It would really be the repaired areas that give me any doubt after a little searching.

Has anyone forgone repainting and just used white gelcoat resin/ repair to fill the ground out cracks and sanded? Did it last?

The only time I did it was as simple as grinding them out with a dremel and filling and covering with plastic to cure. I have no problem investing the time but it will be hard to know the outcome for a quite a while and if a better option exists.

Btw, I will be doing the paint regardless if it is basement only or full body, so the risk of a failed repair is a lot less than a 15k paint job that develops crazing again in short order. Nonetheless, if there has never been a single properly done crazing repair that hasn't kept at least 80% of the cracks away for several years then I probably won't bother doing much more than grinding and sealing them.

Doggy Daddy · 02-17-2015, 12:52 AM

After removing the decals and the adhesive, once should not use rubbing compound or any kind of polish on the fiberglass because it will prevent paint from sticking. After applying paint and clear coat, then one can polish the unpainted white fiberglass to remove the oxidation.

truckin · 02-17-2015, 08:22 AM

Yea, definitely not going to do that. The whole thing will be cleaned and sanded and cleaned again before paint. What I'm trying to determine is if there has ever been a repair to thermal cracking (crazing) that has held up for the most part. Most comments I've read have a story where someone had their coach repainted to hide the crazing but it reappeared.

I am hoping to find someone who has done a repair using either gelcoat or epoxy to the cracks and not had them all reappear. I suspect the repaint jobs were probably the same scheme with the same dark colors which would develop the same problems. My thought is areas repainted in white or light color should hold up much better since it is a heat issue where the dark areas can reach very high temps and the coat cracks because it is trying to expand that brittle gelcoat more than possible without cracking.

I have no crazing in the plain white gelcoat. It was all hiding under the most sun baked dark decals.

Dutch Star Don · 02-17-2015, 10:01 AM

I had a Monaco coach which suffered from the clear coat going bad along the roof line. While was talking to the owner of the RV repair shop, he showed me a coach they were repairing with the crazing. They were using a new primer with some type of strand in it, possibly Kevlar, but I'm not sure.

Mine only needed repainting, until they found a spot on the front cap that had the crazing/cracking. They charged me an additional $500.00 to thoroughly sand the front cap and use the new primer.

truckin · 02-17-2015, 01:04 PM

Ok, so it sounds like there might be people getting decent results when the right material or process is used to do it.

I was torn between just trying to repair the gelcoat with a white color match... or repairing it with a marine resin or epoxy or something else like this stuff you mentioned if I can find it with a full body paint of white and then use light color highlights to break up the white.

I think the epoxy would last longer as a repair than gelcoat, but with epoxy I have to repaint and I didn't want to go thru that huge process if it wouldn't hold.

I will update this thread when I make some progress but until then if anyone has had a crazing repair that is still doing pretty good after a couple years let me know what you did. I'm assuming it involved going to a lighter paint scheme but if it is still good even on the dark areas I would be most interested to know how that was accomplished.

mn.roadking · 02-22-2015, 08:31 PM

For a permenant repair you need to sand completely through the cracked or crazed area. If the fiberglass is cracked you have to go completely through it also. Repair fiberglass with fiber matt, then it can be epoxy primed and painted. If it is gelcoat only you can sand through it and rebuild it with gelcoat or epoxy primer then paint.