# Blisters



## salecm (Sep 8, 2002)

I''m considering purchasing a 1979 Morgan Out Island 41. Broker tells me that owner''s survey has revealed blisters. If left untreated how big a deal is it? Found a web site that suggested $300 to $400 per foot of waterline to correct this problem. How long can I postpone repair?


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## TSOJOURNER (Dec 16, 1999)

Postpone Blister repair? You can''t, you have to take care of them now!!. A Blister is water penetrating the bottom of your boat. If left uncared for you could lose the whole hull. Blister are nothing to fool with. If you have any confidence working with glass you can do this job yourself.I had three first time I pulled my boat. I dug out all the effected area sanded it down smooth leaving a cupped area to lay in new glass. It is a big job and I understand why a $300 to $400 a foot figure is given. But do it yourself or pay but it has to be done and has to be done now. When it all repaired don''t let it happen again use a top grade epoxy paint and solve that problem forever..


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## TSOJOURNER (Dec 16, 1999)

Blisters are really not the problem everyone makes them out to be. Most of the hype was created by companies selling repair regimes. Water is always flowing in and out of your gelcoat. Blisters are just that, a pocket of water between the gel coat and the glass. The glass is not affected by the water, as long as it is sound.

In reality it is simply a image thing.

If you don''t believe me ask a Surveyor. I currently have about 12 blisters on the bottom of my boat and when refinancing neither the bank or insurance company cared one bit about the blisters. Why, they don''t affect the structural soundness of the boat. Maybe the resale value for cosmetic reasons, but not the sea worthyness of the boat.

The best approach is that every time you do a bottom job, fix the worst blisters, budget considered and don''t worry about the rest. Over time you may solve the blister problem without breaking the bank.

Tony


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## TSOJOURNER (Dec 16, 1999)

Ok, When the hull starts getting soft and you can just about push you hand thur the hull tell me it''s not a problem. Left uncared for thats what happends. I still say take care of them NOW. And use the epoxy and rid yourself of blisters forever.


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## Jeff_H (Feb 26, 2000)

Actually there are a variety of causes for blisters and in most cases leaving them alone greatly increases the likelihood of needing a more serious repair. The most common form of blistering occurs when water reaches the by products of the particular thermo-chemical reaction that occurs in some kinds polyester resins. This reaction produces acids that attack the bond between the fiberglass and the resin in the laminate. In doing so the blisters are able to expand deeper into the laminate by traveling down the surface of fiber bundles in the laminate. Over time this can greatly weaken a hull. 

On the other hand, Tony, a dozen or so blisters is nothing to worry about, assuming that you seal them. You also do not say where the blisters are occuring. It is posible to have blisters between the gelcoat or barrier coat, and the laminate. In that case, the blisters are not structural but still should be addressed. I don''t know why you think this is hype but having been around cases where blisters were allowed to continue unchecked until the hull had pretty much delaminated through to the interior in large areas of the bottom, I assure you that it is not just an ''image thing''.

With regard to Jbanta''s comments, one minor point here, you do not want to use an epoxy paint to repair blisters as most epoxy paints are not really made to function as barrier. The best barrier coats are either epoxy resin or vinylester resins (there are advantages and disadvantages to both). In any case where the bliter extends into the laminate a repair with fiberglass and either epoxy or vinylester resin is warranted. 

Jeff


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## TSOJOURNER (Dec 16, 1999)

Jeff
I know I havn''t got the technical speak you seems to have. And yes when repaired my blisters and filled them back in with good glass I used a top quility epoxy resin barrier in six coats.. Maybe a bit of over kill but after repairing blister on my own I made sure I wouldn''t be doing it again...


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## TSOJOURNER (Dec 16, 1999)

The one thing that scares the crap out of me about owning a boat is all of the FUD about blisters. Here are some good links concerning research on the problem:

http://www.cruisersforum.com/forums/showthread.php?t=961&highlight=blisters

The main point I took away from this is that you need to keep your bilge dry.

I skimmed through this and may have misunderstood, but my impression is that blistering is more of a problem is warmer waters.

Question: Is a boat that spent its life in Northern California and northward less prone to blistering?


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## Fstbttms (Feb 25, 2003)

GoLikeaFish said:


> Question: Is a boat that spent its life in Northern California and northward less prone to blistering?


No. The only possible difference is that the cooler water temperatures may slow down any chemical processes, but the the underlying causes of blistering remain, regardless of where the boat lives.


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## TSOJOURNER (Dec 16, 1999)

Fstbttms said:


> No. The only possible difference is that the cooler water temperatures may slow down any chemical processes, but the the underlying causes of blistering remain, regardless of where the boat lives.


Fstbttms, I was hoping you'd chime in on this. Good to know that water temperature retards the problem, even if it's a little bit.

My concern is with the type of blistering that threatens the structural integrity of the hull. In your experience, can you minimize the damage by keeping a dry bilge? (I'm sure no one would argue the benefits of a dry bilge, but its relationship to blisters may not be entirely clear.) Are there ways for a surveyor to detect "bilge neglect"?


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## camaraderie (May 22, 2002)

Go...Fish.....
Don't know where the dry bilge came from but the vast majority of blisters are caused by water outside the hull...not inside. Couldn't hurt to keep it dry but I've had several boats with wet bilges over the last 30 years and no blister issues associated with them. 
Salecm...
I'd walk away from the Morgan if you have more than a handful of blisters to deal with. Too much time and $$ involved to fix properly and there are lots of boats without blisters out there. You can get a discount for the cost of repair...but not the time!


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## Gary M (May 9, 2006)

Northern boats may develop blisters slower if they are hauled out for winter storage and therefore allowed to dry out. Southern boats that are in the water all year may get the pox quicker. 

However blisters are very common everywhere and around the Great lakes where I sail it has become routine to strip off most of the original gel coat and apply about 5-6 layers of either the West system or something like Interlux 2000. Even if they do not have any blisters. Lots of labour but little cost. 

Usually done on boats built with standard polyester resins, usually built before 1985 ?


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## TSOJOURNER (Dec 16, 1999)

Camaraderie,

One of the conclusions of the University of Rhode Island study:

"Deep-seated blistering and delamination of the hull cannot take place unless the polymer in the hull is saturated. Saturation can only occur if the inside of the hull is in contact with water or 100 percent relative humidity air, which results if free water is allowed to remain in the bilge."

http://www.dockwalk.com/issues/2003/august/hullblisters1.shtml

Again, my main concern is with blisters that threaten the structural integrity of the hull.


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## Fstbttms (Feb 25, 2003)

GoLikeaFish said:


> "Deep-seated blistering and delamination of the hull cannot take place unless the polymer in the hull is saturated. Saturation can only occur if the inside of the hull is in contact with water or 100 percent relative humidity air, which results if free water is allowed to remain in the bilge."
> 
> Again, my main concern is with blisters that threaten the structural integrity of the hull.


I think it would be a rare boat that has a serious blister problem on the interior of the hull. I don't remember ever hearing about one. But I would assume that a knowledgable surveyor could determine the integrity of the hull in the area of the bilge.

Edit: Go, I just reread you initial post. The point your are making is that a wet bilge may contribute to blistering on the _outside_ of the hull?


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## Fstbttms (Feb 25, 2003)

Gary M said:


> Northern boats may develop blisters slower if they are hauled out for winter storage and therefore allowed to dry out. Southern boats that are in the water all year may get the pox quicker.


Gary, just as an FYI, here on the west coast of the U.S. (the area in question) and B.C. Canada, boats are not hauled for the winter since freezing is not an issue.


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## FrankLanger (Dec 27, 2005)

With west coast boats being in the water almost year round, with only the occasional haul-out for a day or two for bottom paint, zincs, etc., what do most boat owners do to decrease the likelihood of blisters? I'm sure not everyone can afford to have the boatyards do regular blister repairs. And opinions are mixed on whether it's a good idea to add a barrier coat to older boats--the risk being that they trap any existing moisture and thereby create or aggravate blisters. 
Frank.


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## Fstbttms (Feb 25, 2003)

I'm no expert on blister prevention, but I think that a barrier coat is pretty much the only option. If there are other, common remedies or preventative measures, I'm unaware of them.


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## Gary M (May 9, 2006)

Frank you would have to let your boat sit out for a least a week or two and then you could test the bottom with a moisture meter. It will tell you if you have any significant moisture penetration. 

And I thought everyone on the left coast went skiing all winter. 

Gary


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## Fstbttms (Feb 25, 2003)

Gary M said:


> And I thought everyone on the left coast went skiing all winter.


We do. Water skiing!


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## hellosailor (Apr 11, 2006)

GoLikeA-
If you consider that blisters are the result of water getting into the laminate, and that the laminate has two sides (inside out outside) it becomes obvious why a dry bilge is recommended.
The laminate doesn't care WHICH side admits the water, it can soak in from either. Since the inside may in fact has less protection and more neglect, more unfinished edges, etc, it is worth considering.

Whether blistering is a serious problem, depends on how extensive they are, as well as exactly what kind they are (paint lifting, or internal and full of chemical goo, etc.) If it looks like road rash...it probably is a problem.<G>


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## Parley (Jul 13, 2006)

Ah, Blisters. I've spent a year repairing this issue... part time (very part time). The most common cause of blistering is thru osmosis. Polyester resin is not 100% waterproof. As water reacts with the chemicals in the resin used in the fiberglass layup, a gas is created, and expands. Viola! A blister of the gelcoat is the result.
More often than not, blisters are a result of a "void" (or air pocket) in the original layup. Although not serious initially, it can become quite serious and result in delamination of the hull. Can you say "Catastrophic Failure"? It must be delt with immediately. A more serious condition is what is commonly called "boat pox". This usually shows just as it sounds; hundreds, maybe even thousands of blisters. This condition will likely show the hull to be saturated also. Now you have a very serious condition. The boat would need to be hauled and probably spend at least a summer out drying out. Additionally, the gelcoat will need to be stripped for the hull to properly dry. Only when the hull is sufficiently dry can repairs take place. It is a huge job and very expensive at a yard.
All that being said, I have done my own "blister repair". It is not difficult, nor complicated. However, it is extremely time consuming. One of the biggest jobs I had was getting 30 yr old bottom paint off. Strippers - nope (worked on the outer layers but would not do much of anything to the last layers). I ended up sanding the entire hull. Arghhh.
Yesterday, I spent the morning (had to sail in the afternoon) sanding down my initial fairing work. I was surprised how easy it was. I used the West System. I was expecting it to be much worse than the old bottom paint. I was wrong. I finished half of one side of the boat in just a couple hours.
One note regarding bottom barrier paint (I'm using Interlux 2000E). Everything I've read indicates that this goes over your repairs (like primer). It is not part of the repair. Additionally, it is paint, not epoxy. Use real epoxy for the repairs. 
Hope this helps.


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## KeelHaulin (Mar 7, 2006)

By the way that the quote reads posted by GoLikeaFish; the point being made is that blisters forming in structural layers of fiberglass can only occur if there is water on both sides (exterior and interior). I think that in many cases blister problems are considered a more serious problem than they actually are; in most cases they are non-structural. Blisters usually form beneath the gelcoat or in the first layer (strand-mat which is a non-structual layer). The blisters form in the strand mat because there are air voids and non-saturated glass which allow for water to collect and bacteria to grow and produce molecules which cannot migrate out of the gelgoat/strand-mat. The layers beneath the strand-mat are usually unaffected. If the boat is a solid fiberglass layup; there is usually ~1/2 inch (or so) of structural glass beneath ~1/8" of strand-mat. In the case of my boat (a Newport 41') the structural glass is over 1" thick at the bilge and 3/4" at the rail. When I did the blister repairs the max depth I ground out was 3/16" max to reach clean glass. On my boat I would not call the blister damage structural; they were mostly cosmetic. In boats that have cored hulls or on newer boats that have minimal amounts of structural fiberglass, blisters may be of greater concern; depending on the severity and depth of the blisters.

If your waterline is 35' then the figure of 300-400 per foot brings an estimate of 10.5k to 14k to have a yard do the repairs. I think it depends on the type of repair you are having done. If you are asking them to grind out any existing (visible) blister, re-fair and paint; then you would expect to pay about 1/2 (or less) of what it would cost to strip the hull completely of gelcoat and rebuild the exterior layer with glass cloth, re-fair, barrier coat, paint. I think the 10k figure would be an average estimate for stripping the gelcoat and re-fairing; 14k should also include stripping the strand-mat and rebuilding with glass cloth (but that's JMHO).


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## camaraderie (May 22, 2002)

Go/Fish....I respect the opinion and can understand why a dry bilge would be helpful and something good to strive for. That said...I can't agree with the conclusion that a dry bilge will prevent serious blisters from happening. I have seen too many severe cases with involvement of hull areas far away from the bilge. If outside blisters are left long enough without attention...the driest bilge in the world ain't gonna help the boat...But thanks for the link...couldn't hurt but I can't even reach my bilge! <grin>


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## hellosailor (Apr 11, 2006)

"I can't agree with the conclusion that a dry bilge will prevent serious blisters from happening. "
I don't see where anyone made such a conclusion. As opposed to saying, a wet bilge CAN sometimes cause a saturated hull, with all the attendant problems including blisters.

There's a big difference between those two statements.


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## btrayfors (Aug 25, 2006)

Blisters can be a minor annoyance, an intermediate and expensive problem, or a catastrophic problem. VERY FEW BOATS have catastrophic problems with blisters. EXCEPTION: Valiant 40s built in WA under hull number 250 and above hull number XX (not sure...maybe about 50-80)....these were built with leftover "fire-retardent" resin from an old Navy contract, and have displayed HUGE blisters in the hull, decks, and trunk cabins. You're really asking for trouble to deal with these blister boats, but some stalwart sailors have done so, with mixed results.

Many boats have MINOR blister problems. These DO NOT affect hull integrity. They can be dealt with at haulout time.

Be sure to differentiate PAINT BLISTERS from FIBERGLASS BLISTERS.

Many boats built with "choppers" or other automated processes (not "hand laid up") have blister problems. The location of the boat DOES in fact make a difference. Many boats which appear to be happy in northern climes develop blisters when moved to Florida, the Caribbean or other tropical climes. Heat and humidity DO, in fact, make a big difference on the rapidity of blistering.

As Camraderie said, a dry bilge is a nice thing, but who has one? I lived on a houseboat for 17 years which ALWAYS had water in the bilge and NEVER had a single blister. My present boat of 17 years, a Perry-designed sloop, NEVER has a completely dry bilge. It has had only paint blisters to deal with.

The Morgan OI 41, to my recollection, was a solid hull layup. It could very well be that the blisters are mostly cosmetic. Have an osmosis-repair expert have a look and advise you. Don't depend on ANYTHING you hear here, including this post.

Good luck,

Bill


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## resdog (Mar 29, 2006)

I'll spare everyone my opinions of blisters, but after having done a few blister repair jobs...find a boat without them if possible. Although that may be difficult if you're looking at mid '70's era boats. I sure wouldn't want to do an extensive blister repair on a 41' boat.


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## TSOJOURNER (Dec 16, 1999)

Fstbttms said:


> Edit: Go, I just reread you initial post. The point your are making is that a wet bilge may contribute to blistering on the _outside_ of the hull?


Yes. More to the point: that it contributes to the danger for the blisters go all the way _through _the hull.


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## TSOJOURNER (Dec 16, 1999)

Just to remind everyone: I'm only citing what I perceive to be the conclusions of the study linked from the original post I flagged. I'm just trying to cross-check their conclusions with those of you who spend more time on the water than in ivory towers.

That said&#8230;



resdog said:


> I'll spare everyone my opinions of blisters, but after having done a few blister repair jobs...find a boat without them if possible. Although that may be difficult if you're looking at mid '70's era boats. I sure wouldn't want to do an extensive blister repair on a 41' boat.


The study also indicated blistering is much less common on boats built before 1980. Again, just citing the study, folks!


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## cardiacpaul (Jun 20, 2006)

*valiant blisters...*

ok, folks, everyone has spoke of this... you're talking about 40 boats out of 200

from http://www.boatus.com/jackhornor/sail/Valiant40.htm

"My space is limited and I do need to discuss the blistering concerns. So, I'm not going to go into the usual details of construction other than to say the hulls are solid fiberglass and plastic resin, the decks are cored, and the method of construction has been in line with what should be expected of an offshore yacht. It is the materials of construction not the method that have caused problems with a number of Valiant 40 hulls.

Often the Valiant 40 problems have been more severe than the typical osmotic bottom blistering associated with many production boats of the 1970s and 1980s. My experience has shown a number of Valiant 40 models built by Uniflite between 1976 and 1981 to have severe blisters of the fiberglass laminates, some as large as eight inches in diameter.

Initially the blistering problem was blamed solely on fire retardant resins used by Uniflite. Later research has shown that a combination of sizing used on fiberglass strands chemically reacts with the fire retardant resins resulting in the blisters. This has the potential to be considerably more serious than typical osmotic blisters restricted to areas near and below the waterline. The Valiant blisters affect the entire hull. Most attempts at repair I am familiar with have been unsuccessful, and blisters have redeveloped in as little as two years.

I have heard of several successful repairs, although the solution is very expensive and the last I know of done professionally cost in excess of $60,000. On the positive side, there were 200 Valiant 40s built, and less than 20% have been reported to have severe blistering problems. I do not know of any reported sinking or catastrophic failure resulting from these blisters."

and this...
from http://www.sailnet.com/collections/articles/index.cfm?articleid=jkrets0067

"But the original Valiant 40 does have its warts, or I should say, its blisters. According to Stan Dabney, who has owned hull number 108, Native Sun for 28 years, the well-known account of Valiants blistering because Uniflite switched to fire retardant resin, is only part of the story. Dabney claims that the blisters occurred when Uniflite switched to an inferior resin. "Like other builders, Uniflite was already using a fire retardant resin, but during the energy crunch in the mid '70s, some resin wasn't up to snuff." Dan Spurr, the former Editor of Practical Sailor, wrote in his book, Heart Of Glass, that the questionable resin had a trade name of Hetron.

For a run of over 100 hulls, the Valiant 40's builders used inferior resin, leading to the need for substantial aftermarket repairs on those boats. Here one victim of those circumstances sits in the builder's yard near Lake Texoma after having had its gelcoat stripped.

The results of boats molded with this flawed resin were not pretty. While some Valiant 40s were horribly scarred with deep, structural fiberglass blisters up to 10 inches in diameter and requiring relamination, others experienced cosmetic blemishes restricted to the gelcoat layer. Still, you should be aware that boats built between 1976 and 1981, or hull numbers 120 to 249 all had some degree of osmotic blisters. As a result, a 1975 used Valiant 40 is often more valuable than a 1980 model. Worstell solved the problem for good in 1984 by switching to an isophthalic resin.

So does this mean you should avoid Valiant 40s built during this period? Absolutely not. Although most marine surveyors claim that only way to permanently fix a badly blistered boat is to completely peel the hull and re-fiberglass it, in most cases the blisters are simply unsightly. Blistered Valiant 40s are in some ways, one of the best values on the used boat market. And besides, by now many of older 40s have been properly repaired at some point. "


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## jgeltz (May 11, 2006)

Make no mistake - blisters are serious business. Blisters are the result of a chemical process that deteriorates the polyesters in the hull of a boat called osmosis. Here is an article that addresses the question of whether to buy a boat with blisters:

http://www.yachtsurvey.com/BuyingBlisterBoat.htm

I was very close to buying our dream boat that was determined to have osmosis. The surveyor found blisters that would release liquid under pressure all along the waterline. I investigated and found most people quoting me at least $30K to fix the problem on a 42 foot craft. None would warrant the work for the life of the boat. If the job is not done correctly and the boat not given adequate dry time on the hard once the gelcoat layer is peeled back, it will hasten the return of the issue. I decided to walk.

One more anecdote. We met some folks at our old marina this summer who own a 45' very popular sailboat brand. They bought it new a few years back. Seems last time the yard hauled their boat out, the straps damaged the hull. The yard owned up to it and offered to repair it. When they went to do the work, they found the entire structural integrity of the hull compromised due to water penetration of the core due to osmosis. It appears that the hull is so mushy that its getting hard to launch or haul the boat without damaging the hull. They now are faced with the prospect of spending very significant sums to fix the issue as they know that the boat will not pass a marine survey if they try to sell it. They are devastated as you can imagine.

The only people that I find that write the problem off to an "image thing" are those who are trying to sell a boat with osmosis and those who already have their heart set on buying a boat that is found to have osmosis. I guess the key is to match those two types of folks up! Enter the boat broker...


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## cardiacpaul (Jun 20, 2006)

jgeltz,

this is from the very same article... http://www.yachtsurvey.com/BuyingBlisterBoat.htm

"For older boats, its usually much less of a problem, for the fact is that moderate blistering on an older boat rarely impedes the sale. Unfortunately, another fact of boating life is that there is a great deal of misinformation on this much talked-about subject. *One common misconception is that blisters seriously weaken and/or damage boat hulls. In 30 years of surveying and examining around 4000 hulls, I have seen less than 10 cases where blisters have resulted in serious structural degradation of a hull where it was weakened to a point where some type of failure was immanent. *"

Its not an "image thing", its a fact of life with any fiberglass boat from that era, some more severe than others. No one in their right mind would warrant a blister repair for the life of the boat, just ain't gonna happen.

What I can tell you is that unless the hull looks like the face of a 14 year old with eruptive acne, is that the boat can be repaired.

I would love to know the details of the 45 ft boat that is just a few years old that is now a sponge. That is a very unique situation and something I should be made aware of.


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## jgeltz (May 11, 2006)

I guess it depends on who you ask:

http://www.boatquotes.com/survey101/survey101-992-osmosis.htm

"After blisters have been discovered, the resin break-down process spreads into deeper-lying laminate layers causing the type of damage that is often mis-diagnosed as "osmosis delaminations" or "dry" laminate.

Such damages indicate areas where the resin has been completely hydrolyzed, leaving a void filled with liquid and/or a granular mush of solid resin remnants. These voids can vary in size from minute to a dozen inches in diameter or more.

*If left unchecked for too long, the structural damage can be severe.* The longer you wait the more damage needs to be repaired and the more expensive the cost. Or from another point of view, the less value the vessel will have on the open market."


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## jgeltz (May 11, 2006)

Another quote regarding hull integrity:

http://www.anchorsawayboatyard.com/osmosis_faq.php

"Extensive research and laminate testing showed that osmosis residues are spread throughout the entire laminate, reducing its structural strength by as much as 30%, long before blisters are noticed. In advanced cases, this weakening can be noticed when a boat is hauled as the keel is pushed in, or poppets cause deflections in the hull surface."


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## KeelHaulin (Mar 7, 2006)

I agree with cardiacpaul. I would also add that even if the hull has a severe rash of blisters, it depends on how deep the blisters are and the thickness of the hull in regards to what damage they -may- be causing to the hull integrity. IMHO you would be hard pressed to find an FRP that is over 20 years old that has not had some form of osmotic blistering on the hull. Why? Because nearly all boats produced from the 70's on up have been built with strand-mat as an exterior layer. Think of the strand-mat as a non-structural fairing material; because that's exactly what it is. This material is notoriously bad for having air voids and non-wetted fibers, and is a primary cause for blistering. If you are not willing to deal with the aftermath of a FRP hull sitting in water for 20+ years then you should not be in the market for a used sailboat. If you find a boat that has no visible blisters; it is highly likely that there has been blister repairs in recent history. If you find and buy a boat (old or new) that has never had blisters; there is still possibility that a blister problem will develop. 

Get used to the fact that FRP construction has the drawback of blistering; just as wood hulls have fastener, rot, bug, and caulk problems. If you can't be OK with it then you probably should not own a non-trailered FRP hull.

Also; I think you should "consider the source" when it comes to getting info from the internet and product/service advertisers.
JMHO/FWIW...


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## Fstbttms (Feb 25, 2003)

I have spent 12 years servicing thousands of fiberglass boats in the Bay Area. I have never, ever heard of any boat that was lost or even suffered significant structural problems due to blisters. Not saying it doesn't happen, but it sure ain't common.


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## TSOJOURNER (Dec 16, 1999)

*Valiant 40 Blisters*

Does anyone have experience with blisters on a 1981 Valiant 40? I understand this was a problem with some Valiants but am not sure if it applies to this year. Thanks.
Tom


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## btrayfors (Aug 25, 2006)

teshannon,

The last Valiant 40 "blister boat" was hull #249 owned by Dr. Blaine Nashold in NC. It was a wonderful boat, won several ocean races, and I believe never had blisters because Blaine did a full coal-tar epoxy job on it before they could develop.

Hull #s beginning with 250 and up are OK, as are all those built after Valiant Yachts moved to Gordonville, TX.

Bill


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## sailingdog (Mar 19, 2006)

Some blisters are merely cosmetic..but most are an indication of more serious problems ahead... If they're just the gelcoat, then it isn't as serious as if it involves layers of laminate, which affects the structural integrity of the hull. All blisters should be repaired... and any hulls that have had blisters should be barrier coated in some manner. 

BTW, there were some boats made in the 1970s that had a fire-retardant resin that was more prone to blistering problems IIRC.


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## TSOJOURNER (Dec 16, 1999)

*Valiant 40 Blisters*

Does anyone have experience with blistering on a 1981 Valiant 40? Thanks.
Tom Shannon


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## KeelHaulin (Mar 7, 2006)

sailingdog said:


> Some blisters are merely cosmetic..but most are an indication of more serious problems ahead... If they're just the gelcoat, then it isn't as serious as if it involves layers of laminate, which affects the structural integrity of the hull.


Could you elaborate on this? What do you mean by "most are an indication of serious problems ahead"?

There are three (maybe more) types of blistering IMHO; first is gelcoat which is non-structural, second is strand-mat (common due to fiber wetting and air voids), third would be into the structural laminate (and this would be the only case where the blistering -could- cause structrual problems). Would you agree with this? Would you also agree that the severity of a blistering problem depends on the construction of the hull (solid vs. cored) and the thickness of the structural FRP relative to the depth/size of any blister(s) that are penetrating the the structural laminate?

Tom-

The question you are asking is relative to Hull # on the Valiant 40. What Bill was trying to explain was that boats built prior to Hull #249 were having severe blister problems due to the bad resin; while boats built after #249 were built with a resin that does not promote the formation of blisters. The pre-Hull #249 boats were built with a fire-retardant resin that sailingdog mentions. From what I have read the pre #249 boats had problems with structural laminate blisters in addition to any other form of blistering (an uncommon thing for most FRP hulls). The post #249 boats could still have gelcoat or strand-mat blistering; but I have no idea if there have been ongoing problems with Valiants in this regard.

Hans-Christians have also been notoriously bad for gelcoat/strand-mat blistering; but are still considered a high quality construction boat that is well suited for offshore cruising. I met a man a few months back that owns a Valiant 40 and he had been to the Red Sea twice with the boat and was in the process of refitting the powerplant for more offshore cruising. The only drawback to the boat for him was the engine size relative to the boat displacement; so he was upgrading the Perkins 50HP to a larger Yanmar.

HTH...


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## hellosailor (Apr 11, 2006)

"What Bill was trying to explain was that boats built prior to Hull #249 were having severe blister problems due to the bad resin;"
I've read something more specific on this last week, don't recall where. But it was not "hulls prior to 249" as such, there was a particular SERIES of hulls, something like hulls up to 125(??) were OK and at that point the resin was changed--which led to a series of blister problems. So it is not 'hulls prior to" that are bad, but rather a definite and known series of the hulls. I'd guess any Valiant owners group or a really sharp surveyor or broker could give you the correct specifics on that.


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## cardiacpaul (Jun 20, 2006)

I've posted the link so many times, I'm not going to do it again


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## btrayfors (Aug 25, 2006)

hellosailor,

Yes, that's right. And, you probably saw that on one of my posts elsewhere )

The earliest Valiant 40s were fine, beginning with hull #1. I don't remember the exact hull number when the resin was switched, but it was about 1979-80 timeframe. All hulls built after the switch, and through hull #249, had the POTENTIAL to blister badly. And, with the V40s, we're not talking about normal blistering. These were humongous blisters, some on the decks and trunk cabin as well as the hull.

How do I know this? Because a close friend had a lovely V40...maybe the best one afloat the way he kept it...that developed bad blisters. He was part of a class-action suit which dragged on for years. It was heartbreaking to witness.

In early 1989 I was looking for a non-blister Valiant 40. I traveled to NC and looked at Blaine's lovely "Stormy Petrel", hull #249, which he'd protected by putting coal tar epoxy on the bottom. This was the last "blister boat" built by Uniflite. After agonizing over the potential for major blisters to develop, expecially as I planned to cruise to the Caribbean and keep the boat there for a decade or so, I passed on that Valiant. 

The first boats built after hull #249 did, occasionally, develop some blistering of the type many boats experience. No serious problem. Later, a new process was adopted which, I believe, has all but eliminated even these blisters. The new Valiant 42 built in Texas (actually a V40 with a small bowsprit, built from the same mold) is arguably the best world cruising sailboat in its class.

If I remember correctly, John Krechmer (sp?) of Atlantic Yachts published a treatise on the V40s...no doubt a Google search would turn it up.

Bill


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## T37Chef (Oct 9, 2006)

I love GoLikeafish's comment! 

The fact is (talk to any surveyor) that a lot of boats older than 15 years have some blistering; no matter where they are kept, if they were pulled for the winter, etc. And after you spend all that money (probably $25,000+ or more for a 42') to have someone do it for you, there is no guarantee that it won’t happen again in a few years, even if they say 5 years (read the fine print!) I have seen several that have been done professionally and they look great. For a 26 year old boat worth about $60,00I couldn’t see spending 1/3 of the value on a bottom job. 

Here how I did mine and I’m sure several people will comment on what is wrong...but I'm sailing and loving life:

- had the hull sodablast by a professional
- let it dry for several months, pressure washing it every couple of weeks.
- sanded ALL the remaining bottom paint off
- ground out the large blisters 
- filled and faired everything with West System- added filler
- 6 applications of epoxy barrier coat
- 2 black bottom paint and 1 blue

I spent about $2000.00 total and involved about 60 hours (not including lunch breaks) Its been in the water since July 06, I'll pull it in the spring, we'll see.


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