Repair Procedures - Fiberglass Hull Blisters

[Bernie Eskesen]

Hi; What is current supplies and techniques and procedures,etc, to repair moderate sized, ( several about 2" - 3" in diameter and to a shallow depth), blisters in fiberglass sailboat hulls. Would West Marine Store be a good place to start ? What other sites can you suggest ? Has anyone done some of these and how did it turn out ? My boat, the one that needs the repairs, is about35 years old. Any info would be MUCH appreciated. Bernie Eskesen.

[island trader]

Boat Hull Blisters: Blister Repair Failure Part 2 - by David Pascoe, Marine Surveyor this is very good reading. google blister repair and there is lots of advice. mine would be do you want to open that can of worms? a good repair could take months on the hard.

[jzk]

I have read articles by this surveyor before, and I can't help but think some of it is blown out of proportion. After reading his article on coring, you would think that there aren't thousands of cored boats out there doing just fine, but there are.

[Rhosyn Mor]

Blisters are, in reality not that hard to fix. First thing is that if you do not have too many, dont bother hauling out just to fix them. If you are going to fix them; dry them out, grind them out, Epoxy,coat the boat with Interprotect 2000e ( I think thats the right way round) bottom paint and back in. JZK is right surveyors blow many things waaay out of proportion, there are lots of boats out there with minor cases of blistering, as there are cored hulls.

[Alan Wheeler]

A lot of the way Blisters are dealt with has changed a lot in the last year or two. So what ever information you read, ensure both the information and Author are up to date. The big positive is that blisters are not as bad as some of the old information used to make you believe. The leading Authority on Blister's and what to do about them, is a coatings specialist by the name of Nigel Clegg. Nigel has worked all his working life in the coatings industry and spent 16 years with International Coatings.
Try this site. Passion for Paint - Nigel Clegg Associates

[wallandj]

I used the instructions on the WEST SYSTEM Epoxy site for 4-5 small blister repairs on my boat. They have not returned in two years. Look under the "Projects" tab and then "Boat Repair and Restoration". West Systems sells their 101-6 Maxi-Repair kit with 6 epoxy batches, some colloidal silica, some low density filler and other doo dads. I think its about $35US and should do your job.

The instructions are good but I learned a couple of things at the school of hard knocks: make sure you get the filled mixes thick enough (like peanut butter). Otherwise they droop when you "spackle" them on. And go easy with the colloidal silica filled batch. When it sets up its just a little softer than diamond, making fairing it a challenge. Don't get too much on and finish with the low density filled batch "top coat". It fairs very nicely.

Dave

[mike d.]

if your are in cold climate( haul out in winter) then it would be in your best interest to fix the blisters as when the water mixture freezes it will extend the delaminationa area each time it freezes. blisters are caused by the reaction of water getting to the bonding starch in the chopped strand mat, which attacks the polyester resin and breaks it down. this causes pressure in the area and then ply seperation. as more water gets in the process continues to ever increasing size. the reason for this is that the water follows the strands of fiber glass like a roadway (capilary effect) it can eventually lead to total hull glass layer bonding failure if left to it self. i have seen a few boats that have ended up this way.

[Nauticatarcher]

Easiest way to fix small blisters - just put your boat back in the water

[Ex-Calif]

Originally Posted by Alan Wheeler

Try this site. Passion for Paint - Nigel Clegg Associates

Thanks Wheels. That was a great read. Always nice to get good information for free!

[boatsareme2@yah]

Hello, I am currently doing the varnish on a boat that has just been coated with Awalgrip paint. Some how completly unknown to me, some thing has flattened out some areas on the hull. Is there any thing you can recomend that might bring back the gloss other then re-painting which is not an option. Is it ruined? Or do I just need a water softener and viniger, or awalwash? I am in a complete panic to fix this before boat owner returns. Thank you

[KIWI]

I work in the industry at waikawa marina,
When you apply the epoxy to the blistered area we use masking tape to hold the epoxy in place until it drys this stops the epoxy sagging , The easy"est is to have the tape pre cut to lengths and as soon as you trowel in the epoxy over the blistered area apply the tape don't overlap it put it on edge to edge this will stop the epoxy sagging

[S/V Antares]

I use a small router set to about 5mm or less to hog out my ocasional blisters. This gives a nice uniform depth. Let it dry and Fair out the edges with a grinder and glass in some mat or cloth. Fair it a day or so later.
West system epoxy is my favorite. The Geougeon guys just make it easy with the metering pumps and all the little stuff.

[cottonsail]

In 2008 I bought a 1990 C&C 37 plus. I almost didn't buy it due to blisters. I found a shop in Maryland that specialized in blister repair. The price to put a new bottom on was 11K. I took that off the agreed price with the owner. He reluctantly agreed. My logic was my surveyor found extensive blisters & so would the next surveyor. They replaced 5/16" with new bottom. There were boats from Texas, Canada, California etc all there for bottom jobs. A lot of places would do the job but Osprey marine was the only one to guarantee the job. They did an an excellent job.

[casual]

I am a backyard expert,20 years ago I completly peeled a boat I purchased.Left it dry for 8 months till the moister meeter was acceptable.Washed hull with hot water and let dry with fans blowing on it for 2 days .rolled on a coat of west system,let cure washed again sanded with DA 80 grit,rolled on another coat of west applied a layer of 4 oz mat wetted it out and squezzed out excess expoxy.Let dry sanded with 80 grit washed hull let dry rolled on 8 mor coats of west ,20 years later NO blisters,every 2 3 years a piece of my mat works loose but no moister.All this was done for 11 blisters appx. 1/2 inch to 1 " in diameter.Stuart Yachts in Stuart Fl has a way of doing the process in a month big de humidifiers.I have seen many a quick blister repair return on next haul out.Good luck

[Duke 48]

On my first boat, a Catalina 27, I used a Dremel tool to open the blisters. Let the hull dry then filled the blisters with thickened West Systems epoxy.. No problem.