Another Thor Victim - Bad Fiberglass

31P-RV wrote:
We bought our first motorhome, 2006 Thor Fourwinds 31P, which only had 8300 miles and Mint on the inside. The person we bought it from, was far from honest about the history of the unit. It had all new paint and new decal package on the outside, and looked almost new...
What he did not disclose, was the real reason for the new paint job on the sidewalls of the motorhome. It happens to be one of the 2004, 05, 06, 07 units with the bad fiberglass from Crane Composites, with blisters popping all over the walls.
The previous owner simply had body filler spread over the blisters (pock marks) with no real prep work, sanded, and shot a coat of white paint on the walls...
After we purchased it, the first month it dipped into the 20's (degrees), the filled blister pocks simply started letting go and chipping off... Looks like the walls has been shot with a shotgun...
I have been researching this issue for several months, and feel completely STUPID for being taken so badly with this motorhome and its historic problem.

My question is :
Has anyone successfully fixed one of these motorhomes with th e blisters ?
I have talked to three different RV repair shops near me, and they want $6,000 up to $10,000 to do it, and with NO warranty !!

I am just pursuing if any one has DIY successfully, or do I just need to dump this otherwise nice motorhome ?

Thanks in advance for any help.

The blistering is more than likely air pockets under the glass where it has turned loose from the backing wall, OR air pockets between the glass and gelcoat. Yes you can fix it IF you have experience with fiberglass repair.

You will need to chip off the Gelcoat on the blisters, Sand them, leave them sort of rough to give the resin a foot hold, and depending on if the glass has turned loose from the backing wall. Either roll Roven Woven glass on using a goodly amount of resin. Or use fiberglass matt, again rolling it on with resin. Making sure to roll out the air. I'm thinking matt would be you best bet, as strength shouldn't be an issue. Then sand it smooth, but slightly lower than the surrounding gelcoat, Do feather it out into the good Gelcoat. But leave no sharp edges, as that will leave a ring.

Then you can spray, or even brush paint GelCoat back on. You can get a disposable sprayer at your local building supply. spraying is best.

After that. you will just need to water sand the Gelcoat until it is as smooth as the rest. Hint. Use a block. Just using your fingers will leave "grooves" in the GelCoat. When you get close. Use at least a 400 grit water paper, (600 is better) and plenty of water. The higher the grit the better the shine. Then just buff it out and wax it.

Mixing the hardner with the resin is really the tricky part. You don't want it so hot it sets up too fast, but hot enough that it sets up in a reasonable length of time. You can use a hairdryer to help it along. Much depends on the weather. If it is hot when you do it. Less hardner is needed, cold out? more hardner. Same with the GelCoat.

how is that 6000+ sounding now?

BTW. I was once the "Boat Doctor" at Dixie Boat. My job was to repair new, and used boats to new status, as far as their looks went. Yes, New boats get dinged, and have air bubbles as well. but not when I got done with them.