Gel coat blister

[Guest]

My 1966 daysailer with a baby blue hull developed a blister last summer about the size of a couple of quarters between the gel coat and the underlying fiberglass. The gel coat over the bilster subsequently peeled away leaving a rather unsightly blemish of exposed fiberglass on the otherwise fairly clean hull. It's well above the waterline. I'd appreciate any feedback from the group about how to repair it. Is it possible to match the gel coat? What will happen to the fiberglass if I ignore it?

Mark Miller (miller.mark-at-boston.va.gov)

[Guest]

I have seen colored gelcoat at one boat store that caters to powerboats. You could probably mix white and blue to get a baby blue. I would suppose that you should lightly sand the fiberglass to give the gelcoat something to grab onto. Wear gloves, or your hands will itch like crazy from the glass particles. Then throw the gloves away.

I have heard that raw fiberglass can absorb water and cause it to possibly delaminate. However, I have worked with fiberglass and resins and I kind of doubt this. I think your problem is only cosmetic.

Good luck.
John

John Dura (jdura-at-telcordia.com)

[Guest]

Sorry to dissagree but fiberglass DOES soak up water. Even through "good" gel coat (there are mini cracks)water gets in and older boats will be many pounds heavier because of this. And delamination will occurr at the site of the damage more from mechanical abbrasion than anything. Dry the area with a heat lamp for a long time. You decide. Patience is good. And use foam brushes to "tip off" gel coat. They work best. Follow repair kit instrctions.

Looking at some more of this work myself. It starts on older boats due to water absorption and UV breakdown of the glass. I've tried UV protectants but probably too little, too late. It will continue so be resolved to paint the bottom with good bottom paint as I doubt you'll be able to satisfactorily match the color each and every time you undertake this. Much better to patch and paint.

Enjoy! I'll be sufferin' with you.

MAKurtis (Emak41-at-excite.com)