My boat has some blisters on the hull in some of the areas where it sets on the trailer bunks. They are from 1/4" to 3/8" in diameter. My boat is always trailered to and from the water. My guess is these were caused by setting on the wet carpeted bunks when not in use.

Should I worry about this? Will it cause a big problem if I don't fix it? If I need to repair the blisters, what is a good way to do it. The boat is off the trailer and on jacks so access is good. Thanks.

Unfortunately osmotic blisters are part of boating, just like blown engines, drives etc...The small blisters you're noticing are actually more common than most people know.

The repair is the same as any gel coat repair, grind down, fill and re gel coat. Not fun or cheap. You may want to have a professional inspect the bottom, as unattended they could actually lead to structural problems though it sounds like you are far from that situation.

Check this link:

http://www.diy-boat.com/Pages/Archiv.../blisters.html

West systems epoxy manufacturer has a manual on boat repais and it has a section on blister repair. From what I remember, after you grind away the blister, it is very important to clean the fiberglass. Blisters are created when water mixes with uncured or partially cured resins- they form an acid.

http://www.westsystem.com/

Good Luck!
Bulldog aka Ronnie

I was really hoping to hear someone say

"Gelcoat blisters are very desireable and improve the performance and value of any boat"

Now back to the real world. Looks like I got some work to do over the winter. Oh well, what's new? Thanks for your replys, guys.

If you let them get large enough and they are is a line because of the bunk, you will gain substantial speed due to less wetted surface. Kind of like a catamaran.

I had blisters on a boat one time and had a good result by letting the blisters dry out for 6 or so months, then barrier coating the bottom with a two part epoxy. Really came out nice, but was a lot of work, and I suspect you may not want bottom paint.

BT

Had them on a previous boat, in the first year, at the water line.
Boat stayed in the water. They were smaller than yours. Had them repaired by a local shop. Said he wouldn't guarantee, but never had one come back. Lasted 2wks, got rid of boat.
Now I'm checking for them every time I wipe down my boat.
What year is yours? Heard the epa forced manufactures to quit using certain products and the builders didn't have time to come up with replacment and had to use some inferior products.
Around 96-98? Don't know if its true. Good luck. John

It's a '93.