Blisters

[Mike Cummings]

We have just finished sanding all the paint off the bottom and have a couple of typical blisters.Howver, about three feet below the water line running from the bow back to the middle, a 1 foot wide section has tiny circles that would appear to be blisters. When we try to pop them the gel coat stays firm.Is this the start of something??? Prior owners did not do alot of sailing and the boat mainly sat at the dock.Planning to fix the normal blisters and apply 4 coats of Interlux 2000 and then bottom paint.Any comments?Mike

 

[John K Kudera]

Blister Fix

Hi Mike,I had some blisters too a few years ago, I popped the ones that were obviously blisters, and left the others alone. I too used the Interlux epoxy with two coats, and have had nothing show for several years.What you see may be some imperfection in the gell coat. The barrier coat should be enough protection.Good luck,John

 

[Clyde Lichtenwalner]

Tough call

What you see may be the start of blisters. I call it acne, and I have seen it on my boat. Generally I sand it until smooth, and if I can't burst blisters I don't worry about it. The kink here is your plan to barrier coat. The barrier coat may be a total waste of time and money unless the gel coat is removed and the area dried (perhaps over the winter). On the other hand, you may never see the acne again. I barrier coated my boat 16 years ago (at the dawn of blisters). I still get occasional acne outbreaks and blisters. I usually repair them as they appear, being sure to use plenty of epoxy on the bare laminate and re-barrier coat in the local area of the blisters. Depending on how you plan to manage your boat, you might consider skipping the barrier coat this year and if you haul at season's end, look into the problem more rigorously next fall. Sand early, find blisters, open them, let them dry for the winter and repair and barrier coat next spring. I think there is a better chance of the barrier coating doing some good. On the other hand, these boats are not particularly blister-prone, so there is a good chance you'll find no blisters at all next fall. It's a real crap shoot. Good luck whatever you decide.