Bubbles in the hull

Ok here is one. I have an 81 h16 and there are bubbles in the hull. Looks like delamination but in no way are they soft. I have had it for 3 yrs and never have felt soft. So what do you guys think? Already been repaired? Or am I missing the boat here on something. Thanks

Small roundish raised (bubbles) may mean the hull was in the water or stored in a place very wet. That is water absorbed and pops the gel coat out a bit.

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Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

So what should I do to fix that? I currently moor my Hobie all summer in the lake. Is this a huge no. I figured the hulls were sealed and they are absolutely dry inside. I pull the plugs and not a drop if water leaks out. What can I do to fix it. Some are the size of plates and some are the size of softballs. They are not soft though. What should I do and how can I fix it?

Mooring has several issues. The hull materials are not fully sealed for long term immersion. You need a bottom paint to prohibit the water absorption into the materials. Constant motion of the water causes accelerated wear on parts. Best pulled ashore or onto a float.

I believe a fix would require grinding he blisters down and filling.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Blisters occur when moisture gets to some of the unreacted chemicals in the fiberglass and acid forms. If you break open a blister it will smell like vinegar. It happens more in warm fresh water than salt water. My monohull developed many blisters after a couple of years of being kept year round in a lake. I had to have someone completely remove the bottom gelcoat and some fiberglass to repair it. A fiberglass repair manual will describe it. Small blisters can be individually removed and patched as Matt described. Research it on the web. Bottom line is that keeping a fiberglass boat in water, especially fresh water, can cause the problem.

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Howard

So you think the best solution is grind them down fill refair it out. What would you use to seal the hull? I can get it sprayed and sealed? My situation is that I don't have the availability for a float or beach. I have only all my life used vc17 on the hull of my monohull.

Take a look at this link. I can't vouch for the repair methods or how well it applies to a Hobie hull but it looks pretty good. I tried to find the book I had on fiberglass repair but couldn't. If I locate it, I'll see if there is more information. As mentioned in the link, be careful if you break open any blisters. Wear eye protection since there could be pressure built up and the liquid is acidic.

http://www.boatus.com/boattech/casey/03.htm

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Howard

I bought my boat from a guy who had taken it apart and stored the hulls for several years on their outboard sides lying on the damp ground beside his garage. There were dozens of gel coat blisters on each hull. I carefully opened them up with a dremel tool and sanding wheels. Most were dry but the larger ones had moisture in them. After letting the wet ones dry for several days I filled each with Marine Tex. I sanded and and painted the hulls with West Marine SeaglossPro Polyurethane paint. Four years later everything still looks good.