osmotic blistering 34

[earl womack]

My 1986 34 ft Hunter has small osmotic blistering through out the bottom. Is there danger of the gell coat peeling or delaminating? Has anyone else had problems with this problem?

 

[Capt James Scannell]

Blistering 34' Hunter

Darn right there is danger of the gelcoat peeling. If the blister is small it can be sanded away. I would see a marine yard dealer for an evaluation. Once water penetrates the gelcoat the structral core begins to rot.When water is in the core lining it becomes a major expense to correct.Best corrective measure is a barrier coat followed by a few coats of anti-fouling protection paint.

 

[Clyde Lichtenwalner]

Common problem

Most 34s have only minor blister problems compared to other production sailboats. What you have is acne, not melanoma, at least if your blisters are the same as most I have seen on this vintage Hunter. They should be looked after, but will probably require less than the full gel coat peel and replacement that some will try to sell you (cost equal to a third the value of your boat). There is plenty written in these archives on this subject so I will leave you to research and learn on your own. I have been repairing blisters as they appear for the last 15 years and can report that at this years haulout (after two years in the water) there were none. I barrier coated when the boat was two years old and showed its first acne. I have reparied 50 to 80 blisters, as they appeared, in the years since. Repairs are simple, but time consuming.

 

[Christof Walsdorf]

Blistering

You don't have to worry about core rot too much. Hull below waterline and about two inches above are solid fiberglass. That is not to say that fluids cannot penetrate layers of glass, your balsa core won't be affected by blisters, however.Good luck!