Blistering in the poor mans fiberglass a year after build?

[Chello]

I built this camper last February, and it has had a nice smooth exterior since I finished it. I walked past it this afternoon and suddenly it has random bumps on the outside.

It's 2 inch foamboard with canvas glued on and then several coats of exterior paint.

Has anyone else had this problem? Is there an easy fix? Like just popping them and injecting some glue?

[i

[ghcoe]

My trailer showed some bubbles. It was in a area that I did not sand or clean with alcohol before I painted. I had already painted, so I went ahead and applied the canvas. A few months later I noticed that I had bubbles in that area. Luckily it was on the bottom side of my hatch so it did not show on the outside. I have had no bubbling issues where I had sanded and/or wiped down with alcohol before painting and canvasing.

I repaired the bubbles with a small syringe with needle. I poked two holes into the bubbled area right along the edge of the bubble opposite of each other. Then I injected diluted TBII through one hole and let it flow out the other hole. I really had to dilute the TBII down to get it to flow properly through the small needle. Once the glue was injected I was able to press down on the bubble with my finger and smooth it out. Could not even tell there was a bubble there once done. With the small needle I used you could not even see the holes. Bubbles have not returned so thinking that it is a permanent fix.

I really think that surface prep is the key to having no bubbles.

Good luck

[Papi]

I've had several places like that develop. On the larger ones I just left them alone, and the larger ones I carefully peeled back the canvas and cleaned the substrate, then glued it back down. Fortunately they were on the roof and not visible to the casual observer. I don't know what causes the blistering.