Have you had problems with blisters on your hull? Was it a mild case, or is your local boat yard much richer for the experience? How old is your boat? How did you handle the problem? Did you tackle it yourself or hire the job out to the pros? Finally, what did you do to prevent the problem in the future? Share your blistering thoughts here, then vote in this week's Quick Quiz at the bottom of the home page.
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Larry W.
blisters
My '94 Beneteau 40 had a moderate case of blisters last time I hauled out. I had them spot repaired at a local yard by a BMW I'd used before. It was still within the warranty period and Beneteau kicked down $600 for the job, but I don't think blisters are the huge scary thing they're made out to be. I plan to just fix the obvious ones I find at each haulout, paint and splash. A friend of mine had a complete blister job done on his boat and they still came back. It cost $4500 and six weeks on the hard for a thirty foot boat.
My '94 Beneteau 40 had a moderate case of blisters last time I hauled out. I had them spot repaired at a local yard by a BMW I'd used before. It was still within the warranty period and Beneteau kicked down $600 for the job, but I don't think blisters are the huge scary thing they're made out to be. I plan to just fix the obvious ones I find at each haulout, paint and splash. A friend of mine had a complete blister job done on his boat and they still came back. It cost $4500 and six weeks on the hard for a thirty foot boat.
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Bob Camarena
Several each year
I have a 1981 C-30 which is kept in freshwater. Every time I haul for bottom painting (every 2 years on avg). I have a few (10-15)new blisters, generally not bigger than a quarter, plus a few, failed repairs. I've done my own repairs, leaving the sanding and bottom painting to the yard. The last time I repaired with West System epoxy plus a barrier coat over the repairs. It may be my imagination, but there seem to be fewer blisters each time so I guess I'm gradually doing a complete bottom job. My experience was similar with my '76 C-27.
I have a 1981 C-30 which is kept in freshwater. Every time I haul for bottom painting (every 2 years on avg). I have a few (10-15)new blisters, generally not bigger than a quarter, plus a few, failed repairs. I've done my own repairs, leaving the sanding and bottom painting to the yard. The last time I repaired with West System epoxy plus a barrier coat over the repairs. It may be my imagination, but there seem to be fewer blisters each time so I guess I'm gradually doing a complete bottom job. My experience was similar with my '76 C-27.
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Sam Lust
Not One!
This past winter I sand blasted the entire hull of my 1983 Hunter 33 and I didn't find a single blister. I was actually surprised, although certainly not disappointed. To make sure it never happens, after several months of drying time I sprayed on 6 coats of Interlux interprotect, ending up with a coating of between .015 and .030 inches (More overkill. Lots of work but I expect to have this boat for at least 10 years to come. (We Hunter 33 owners do like our boats!)
This past winter I sand blasted the entire hull of my 1983 Hunter 33 and I didn't find a single blister. I was actually surprised, although certainly not disappointed. To make sure it never happens, after several months of drying time I sprayed on 6 coats of Interlux interprotect, ending up with a coating of between .015 and .030 inches (More overkill. Lots of work but I expect to have this boat for at least 10 years to come. (We Hunter 33 owners do like our boats!)
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Don Evans
Don't Know What To Believe...
After wading through the articles posted at osmosisinfo.com (not easy, its highly technical...and I have a chemical degree), I'm wondering if perhaps we are all being taken by osmosis barrier companies who tout that their products will end the dreaded pox. Well there seems to be many who still get blisters after barrier proofing (40% by the authors research). The radical theory they pose has little to do with osmosis and more to do with uncured resins and "trigger" fiberglass strands that act as capillaries that draw water into the resin pockets. The author's suggest that NO epoxy barrier be applied after blisters appear, until a complete "post" heat cure and acid removal can be accomplished. They suggest to grind out the blister and paint with anti-fouling as a minimum and to have the hull repaired by a yard that can properly heat, wash and refare the hull. It makes for interesting reading, all be it highly technical. After adding a barrier coating 10 years ago, I have not seen one blister on my O'Day 25. It's difficult to know if I would have had I not done so. Don
After wading through the articles posted at osmosisinfo.com (not easy, its highly technical...and I have a chemical degree), I'm wondering if perhaps we are all being taken by osmosis barrier companies who tout that their products will end the dreaded pox. Well there seems to be many who still get blisters after barrier proofing (40% by the authors research). The radical theory they pose has little to do with osmosis and more to do with uncured resins and "trigger" fiberglass strands that act as capillaries that draw water into the resin pockets. The author's suggest that NO epoxy barrier be applied after blisters appear, until a complete "post" heat cure and acid removal can be accomplished. They suggest to grind out the blister and paint with anti-fouling as a minimum and to have the hull repaired by a yard that can properly heat, wash and refare the hull. It makes for interesting reading, all be it highly technical. After adding a barrier coating 10 years ago, I have not seen one blister on my O'Day 25. It's difficult to know if I would have had I not done so. Don
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Jack
None
I have had a 1977 Cat 22, a 1978 Cat 25, and a 1986 Hunter without any blisters. I have seen boats of the same year, and model with blisters which were on the same lake. I agree it is a layup process issue as oppossed to an osmosis issue. I have never used a barrier coat. Just for the record I have seen blisters on Hunters, Catalinas, Beneteaus, Ericsons, Pacific Seacraft, Sabre, Tartans, Irwins, Watkins and CCs. Those are just the ones I remember.
I have had a 1977 Cat 22, a 1978 Cat 25, and a 1986 Hunter without any blisters. I have seen boats of the same year, and model with blisters which were on the same lake. I agree it is a layup process issue as oppossed to an osmosis issue. I have never used a barrier coat. Just for the record I have seen blisters on Hunters, Catalinas, Beneteaus, Ericsons, Pacific Seacraft, Sabre, Tartans, Irwins, Watkins and CCs. Those are just the ones I remember.
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Vicky
Blister Misinformation?
When we were searching for our "new to us" perfect boat (1980 - 1990 vintage), we found that MANY of the boats we looked at had blisters of varying degrees. This promted us to do significant amount of research into the technical reasons and solutions for blistering. I would recommend reading www.yachtsurvey.com in particular the article under Blisters, entitled "To Buy or Not to buy..the blistered boat." The writer has put into very simple language some of the same information we also found. Bottom line, some blistering is merely cosmetic and not structural and therefore may not warrant any immediate repair.
When we were searching for our "new to us" perfect boat (1980 - 1990 vintage), we found that MANY of the boats we looked at had blisters of varying degrees. This promted us to do significant amount of research into the technical reasons and solutions for blistering. I would recommend reading www.yachtsurvey.com in particular the article under Blisters, entitled "To Buy or Not to buy..the blistered boat." The writer has put into very simple language some of the same information we also found. Bottom line, some blistering is merely cosmetic and not structural and therefore may not warrant any immediate repair.
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Edward Kennedy
Blisters to Starboard
When I bought my 1981 Hunter 37 cutter last year, everything looked OK to both my serveyer and myself. Iwas therefore surprised to find that after I removed approx. 10 layers of old bottom paint, thet there was hundreds of tiny, approx. 1/4 inch across, blisters on the starboard side of my hull. The port side was completely free of any blisters. This makes me think that the blisters have a lot to do with layup. They probably sprayed the entire bottom with gelcoat, but layed up the first layer of cloth on one side before the got to the other side. I haven't worked on them yet, but maybe this winter I'll start fixing them. Any suggestions?
When I bought my 1981 Hunter 37 cutter last year, everything looked OK to both my serveyer and myself. Iwas therefore surprised to find that after I removed approx. 10 layers of old bottom paint, thet there was hundreds of tiny, approx. 1/4 inch across, blisters on the starboard side of my hull. The port side was completely free of any blisters. This makes me think that the blisters have a lot to do with layup. They probably sprayed the entire bottom with gelcoat, but layed up the first layer of cloth on one side before the got to the other side. I haven't worked on them yet, but maybe this winter I'll start fixing them. Any suggestions?
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Ken B
not to bad
My wife and I just bought a 1972 Oday 22 that had been sitting anchored for at least three years. I could not believe my eyes, after scraping barnacles the size of golfballs off her belly, and found only one blister on the hull and about twenty on the keel. My solution was a pretty harsh one, I broke out the old electric angle grinder and went to town(if you choose this route, please make sure that you, or someone you know, knows how to fix fiberglass)
My wife and I just bought a 1972 Oday 22 that had been sitting anchored for at least three years. I could not believe my eyes, after scraping barnacles the size of golfballs off her belly, and found only one blister on the hull and about twenty on the keel. My solution was a pretty harsh one, I broke out the old electric angle grinder and went to town(if you choose this route, please make sure that you, or someone you know, knows how to fix fiberglass)
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DENNIS JOHNS
o'DAY BLISTERS
We have a 1982 O"Day 34 and have never had any blisters. The bottom paint is usualy redone every two years. The steel keel does take some extra maintenance.
We have a 1982 O"Day 34 and have never had any blisters. The bottom paint is usualy redone every two years. The steel keel does take some extra maintenance.
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Jeff Walker
a bunch
My '83 was really peppered with them. Nothing structural but I finally bit the bullet and stripped the gel coat, dried, and re-sealed.
My '83 was really peppered with them. Nothing structural but I finally bit the bullet and stripped the gel coat, dried, and re-sealed.
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Robert Polk
At the 15 year mark
I have had two boats that required a "blister job" when they became about 15 years old. One was a 1978 Ranger 33 and the other was a 1986 Express 35. I have a friend who is a surveyor who I believe is an autority on the subject and he profiles the affecyed by grinding away the bottom over a 6 inch radius to expose each layer and then he inspects each and taks moisture readings and hardness tests for the gelcoat and the first two layers of fiberglass cloth. After analysis, his recommendation for repair is to remove the gel coat and each layer of affected glass matt and then apply epoxy and layers of glass to work back to the original thickness and finish with epoxy. Seems to work well. We have a new Hunter 460 and he recommened applying at least 3 coats of an epoxy barrier coat manufactured by AwlGrip. He has samples of all the major brands of barrier coats applied to the similar glass sample strips. He leaves them in the water at his dock and tests them annually. He says the Awlgrip product works the best. If you do this to a new Hunter, you must get prior approval from Hunter or risk voiding the 5 year warranty. Hunter approves of this procedure.
I have had two boats that required a "blister job" when they became about 15 years old. One was a 1978 Ranger 33 and the other was a 1986 Express 35. I have a friend who is a surveyor who I believe is an autority on the subject and he profiles the affecyed by grinding away the bottom over a 6 inch radius to expose each layer and then he inspects each and taks moisture readings and hardness tests for the gelcoat and the first two layers of fiberglass cloth. After analysis, his recommendation for repair is to remove the gel coat and each layer of affected glass matt and then apply epoxy and layers of glass to work back to the original thickness and finish with epoxy. Seems to work well. We have a new Hunter 460 and he recommened applying at least 3 coats of an epoxy barrier coat manufactured by AwlGrip. He has samples of all the major brands of barrier coats applied to the similar glass sample strips. He leaves them in the water at his dock and tests them annually. He says the Awlgrip product works the best. If you do this to a new Hunter, you must get prior approval from Hunter or risk voiding the 5 year warranty. Hunter approves of this procedure.
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Don Wilson
Dime size Blisters
When I hauled my boat last November I found numerous small dime sized blisters on both the port and starboard side of the hull. I called Hunter and as the boat was only 3 years old they agreed to have the blisters repaired. I took the boat to a good Hunter dealer and had the work done to the tune of some 3K . The dealer did a good job but said that the problem was in the Gel Coat and not the Fiberglass. No structural damage was done. Two layers of Gel Coat were applied at the factory and water got between them causing what appeared to be serious blister problems. At any rate I have a new bottom and we will have to wait to see how it holds up. The boat is in the water for about 8 months a year and the water is sweet in our part of the Chesapeake Bay.
When I hauled my boat last November I found numerous small dime sized blisters on both the port and starboard side of the hull. I called Hunter and as the boat was only 3 years old they agreed to have the blisters repaired. I took the boat to a good Hunter dealer and had the work done to the tune of some 3K . The dealer did a good job but said that the problem was in the Gel Coat and not the Fiberglass. No structural damage was done. Two layers of Gel Coat were applied at the factory and water got between them causing what appeared to be serious blister problems. At any rate I have a new bottom and we will have to wait to see how it holds up. The boat is in the water for about 8 months a year and the water is sweet in our part of the Chesapeake Bay.
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Russ King
Regional variations
An interesting pattern seems to emerge from the replies. The further north the owner is, the fewer problems. New Jersey and Washington state responses indicate few or none. The California and Florida responses indicate many. An interesting question is: are blister problems connected to warm climates? The anecdotal evidence here, plus information I have gleaned from other sources, indicate that climate (especially warm, humid) is a factor.
An interesting pattern seems to emerge from the replies. The further north the owner is, the fewer problems. New Jersey and Washington state responses indicate few or none. The California and Florida responses indicate many. An interesting question is: are blister problems connected to warm climates? The anecdotal evidence here, plus information I have gleaned from other sources, indicate that climate (especially warm, humid) is a factor.
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Tom
Russ, I think one of the factors that northern
boats have less blisters might be due to the fact that the boat is in the water less often. Down south and florida people tend to keep the boat in the water year round and only take it out every so often to paint the bottom. Up north most people take the boat out for an average of 5 months per year. I think this gives the hull a chance to "dry out" per se.
boats have less blisters might be due to the fact that the boat is in the water less often. Down south and florida people tend to keep the boat in the water year round and only take it out every so often to paint the bottom. Up north most people take the boat out for an average of 5 months per year. I think this gives the hull a chance to "dry out" per se.
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Russ King
Northern climes would show other problems.
I don't disagree that a boat can last longer if it is out of the water a good part of the year. Where I live, boats are only in the water 5 or 6 months because of the short season. But northern climates have their own problems: freezing. If any water is in the laminate (that's the basis of a blister), the freeze/thaw cycle would destroy the fiberglass. But that doesn't happen, or rarely happens. An interesting question for those people with blisters: Is the fiberglass sealed in your bilge? Contrary to popular belief, fiberglass is porous, which is the reason we have a gel coat on the outside. If water gets into the interior, it can wick into the fiberglass. Other problems can occur with condensation in the interior wicking into the fiberglass in areas other than the bilge.
I don't disagree that a boat can last longer if it is out of the water a good part of the year. Where I live, boats are only in the water 5 or 6 months because of the short season. But northern climates have their own problems: freezing. If any water is in the laminate (that's the basis of a blister), the freeze/thaw cycle would destroy the fiberglass. But that doesn't happen, or rarely happens. An interesting question for those people with blisters: Is the fiberglass sealed in your bilge? Contrary to popular belief, fiberglass is porous, which is the reason we have a gel coat on the outside. If water gets into the interior, it can wick into the fiberglass. Other problems can occur with condensation in the interior wicking into the fiberglass in areas other than the bilge.
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Jack
Climate?
All of the boats I have seen with blisters are only in the water 7-8 months and usually on the hard for the rest. A friend of mine had a Cat 25 that blistred in the first 5 months. No conclusion but who knows. I still think it is caised by poor initial layup.
All of the boats I have seen with blisters are only in the water 7-8 months and usually on the hard for the rest. A friend of mine had a Cat 25 that blistred in the first 5 months. No conclusion but who knows. I still think it is caised by poor initial layup.
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Craig Cody
Blister repair nightmare
First, I don't think that climate has a lot to do with it. Seattle boats are in the water year around, and not hauled for the winter. Cooler water isn't necessarily a factor, as our sea water here in Santa Barbara rarely gets above 60 degrees. I had a '78 C30 and it had absolutely no blister. My '85 C36, however, is a different story.... When I bought the boat about 2 1/2 years ago, the bottome had THOUSANDS of blisters from the size of a dime up to about 2 inches across. I think it was poor layup. Anyway, as part of the sales deal, the seller agreed to fix them. I took the boat to a yard about 35 miles from Santa Barbara (a yard owned, incidentally by Frank Butler). Finally, after 3 1/2 months of beggin, pleading, cajoling and threatening, the boat was finished. (They didn't even start work on it for almost 6 weeks). It turns out that the yard used a 3M product that 3M has since decided isn't and never was suitable for use on boat bottoms. 3M says it is the yard's fault for using an unsuitable product, the yard says that they didn't know and that 3M should pay, Frank Butler wants to know why either he or 3M should suffer just because I have a product on my boat that is known to fall off in chunks. He said that once it starts falling off, I should call him and maybe he can help me. 3M has generously offered to reimburse me for the cost of new materials (about $300) when I have my bottome stripped and redone. My share would only be about $5,000.00. Now we all know why lawyers can afford big boats and new Mercedes. It looks like I will have to sue. All I want to do is sail.
First, I don't think that climate has a lot to do with it. Seattle boats are in the water year around, and not hauled for the winter. Cooler water isn't necessarily a factor, as our sea water here in Santa Barbara rarely gets above 60 degrees. I had a '78 C30 and it had absolutely no blister. My '85 C36, however, is a different story.... When I bought the boat about 2 1/2 years ago, the bottome had THOUSANDS of blisters from the size of a dime up to about 2 inches across. I think it was poor layup. Anyway, as part of the sales deal, the seller agreed to fix them. I took the boat to a yard about 35 miles from Santa Barbara (a yard owned, incidentally by Frank Butler). Finally, after 3 1/2 months of beggin, pleading, cajoling and threatening, the boat was finished. (They didn't even start work on it for almost 6 weeks). It turns out that the yard used a 3M product that 3M has since decided isn't and never was suitable for use on boat bottoms. 3M says it is the yard's fault for using an unsuitable product, the yard says that they didn't know and that 3M should pay, Frank Butler wants to know why either he or 3M should suffer just because I have a product on my boat that is known to fall off in chunks. He said that once it starts falling off, I should call him and maybe he can help me. 3M has generously offered to reimburse me for the cost of new materials (about $300) when I have my bottome stripped and redone. My share would only be about $5,000.00. Now we all know why lawyers can afford big boats and new Mercedes. It looks like I will have to sue. All I want to do is sail.
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Jim WIllis
What was the 3M product`
3 and a half years ago I used 3m vinyl ester patch on the few blisters I had above the barrier coat. I want to use all this input in "FIberglass TRilogy III "blisters and their repair" now being written for the glecoat and plastics forum. By the way, I think that blisters do form faster in warm water. We have a big problem here in Hawaii and the problem was srose on the side of the boat facing the sun. Thank' Jim W
3 and a half years ago I used 3m vinyl ester patch on the few blisters I had above the barrier coat. I want to use all this input in "FIberglass TRilogy III "blisters and their repair" now being written for the glecoat and plastics forum. By the way, I think that blisters do form faster in warm water. We have a big problem here in Hawaii and the problem was srose on the side of the boat facing the sun. Thank' Jim W
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Jeff
Water Temperature
I have been told by a surveyor that blistering progresses slower in cold water than in warm water. Therefore the answer to the question regarding whether boats in northern climates have fewer osmosis problems than southern boats may be true, that is if they stay in the water all year round. A boat with blisters on the hard in 30 below weather is bad news. Here in the northwest we have the best year round climate for boats. Cold water for the hull, lots of rain for the topsides and rigging to wash away salt and moderate temperatures tear round.
I have been told by a surveyor that blistering progresses slower in cold water than in warm water. Therefore the answer to the question regarding whether boats in northern climates have fewer osmosis problems than southern boats may be true, that is if they stay in the water all year round. A boat with blisters on the hard in 30 below weather is bad news. Here in the northwest we have the best year round climate for boats. Cold water for the hull, lots of rain for the topsides and rigging to wash away salt and moderate temperatures tear round.
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