gelcoat blisters

[Caliente]

Just had to do extensive work on the hull of my 2000 Luhrs 32' Express because of gelcoat blisters. Most of the blisters were on the chines which would lead me to think the voids were left in the fiberglass during the hull layup. Has anyone else had similar problems?

[Esquire]

What did the blisters look like? Were they wet or dry? The osmotic process that causes the blisters loves warm water, the chines being exposed to the warmest water are most likely to get them. I have a 2000 360 Conv. and while working on the hull this spring noticed a crack in the gel coat on the chine, I found a void about an inch and a half long and about an inch wide, but it was dry as a bone and was not a blister. I removed the loose gel coat and filled it with an epoxy designed for the job. That is why I asked if your blisters were wet inside. I dont think that hull voids necessarily cause blisters, what did the yard say that did the work or did you undertake to do that horrible job your self???

[Caliente]

The osmotic blisters were liquid filled voids that I opened,cleaned and refilled with epoxy/high density filler.I have wondered if Luhrs has any warranty coverage for such obvious hull layup voids.

[Caliente]

I forgot to tell you that everything I have researched on osmotic blistering said that the blisters are caused by the voids left during hull layup.

[Esquire]

The problem that I found while researching the subject is whether there is a general agreement on whether getting blisters automatically means poor layup... one article I found said "the majority of GRP vessels have myraids of small voids throughout the construction"... there also seems to be a definite turn in attitudes on if in fact they even need to be repaired, several articles I found strongly seemed to advise that in most cases the blisters are cosmetic only and will never affect the structural integrity of the hulll, of course if you go to a yard they will tell you that it HAS to be fixed...saw some pictures of Bertrams, Hatteras and Cabo hulls with blisters... all arguably the "upper crust" of boat builders... so it sure seems to be an area with many differing opinions depending who you talk to... very frustrating at least but it would seem that you have got nothing to lose by contacting Luhrs and see what they would do about it.

[Momentai]

My 1998 38 Open is in the process of having the bottom completely sand blasted, 4 primer coats, Interlux, and two antifouling finish coats.
After the sand blasting, there are several voids, nothing major, all minor, but there are numerous. Yards is not concerned, says hull is excellent. They are going to seal and fill. First primer coat done, 3 more to go and they are filling the voids before 2nd coat. Then, 2nd coat and same process until they are flush and filled.
In my case, the boat 1998, had several coats of non-compatible bottom paint jobs, since she had 3058 hours, she is a good one. Once we did the evaluation and decided to take the hull down to original, which sand blasting preps better than when the factory did the first bottom coat, she will have the best bottom protection possible...again better than when she was new from the factory.
Expensive but most important part of the boat in my opinion.
Summary, voids can be result of 1) like factory lay up 2) poor hull maintenance 3) in adaquate factory prep and proper paint for conditions 3) as time passes and conditions where the boat is used and moored, bottom is not updated to meet new water conditions.
Hope this long winded experience is helpful to others.