Hull blisters

[localboy]

We are communicating with a broker on a 1991 Monk 36. Broker was very forthcoming that the boat has hull blisters that were present when the current owners purchased the boat 10 years ago. They were apparently not remedied.



I have read up a lot on this and get the impression that hull blisters are quite common in f-glass boats of this age/era. They can become an issue if larger than 4" in diameter or they are numerous and cover a lot of the hull. Also it is thought that either bad hull lay-ups or inferior/cheap resins are the main cause of hull blisters. I know some boats have a documented history of blisters occurring in greater frequency than others.



I have inquired with the broker to describe this in more detail. We talking "pimples" or is the hull covered in large blisters?



My question is, in general, do these boats have a reputation of this occurring? Was this era boat built in Taiwan or Canada?



Any info from you is appreciated. I am not yet retired and don't have the time to devote to hauling, grinding, drying, repairing etc right now, so this may be a pass for us on this particular boat. Either way, any more info will provide more knowledge for our (possible) continued search.

 

[mvweebles]

Google "blistology" by Steve D'Antonio and keep clicking through URLs for more information.

My 1970 Willard 36 had a crop of blisters when I purchased her in 1998 for which I received a decent survey credit at the time. Blisters numbered in the 100s and sized around a quarter to a couple inches. Many Willards have blisters but there is no known issue with structural integrity. I consider them to be cosmetic.

As part of a larger refit in Mexico, the blisters are being repaired on a case by case basis (vs peel and reglass). They may or may not reappear. I really don't care.

I don't know about Monks or even Taiwan trawlers of the era. But if you are bothered by blisters, don't buy a fiberglas boat. Below waterline blisters are fairly common.

Read articles from qualified experts such as Steve D and others he cites from the USCG. My. Impression is I accept blisters as a common flaw of fiberglass boats.

 

[psneeld]

The trick is how bad hydrolysis in the boat may be.

Boats with or without blisters my have severe hydrolysis.

Even tapping did not reveal the bad hydrolysis in my boat....moisture meters showed moisture...but it was interpreted as blister and gel saturation...."cosmetic".

 

[DrissZougari]

I had the luxury of purchasing a Carver twenty years ago. TheseBoats were known to develop tones of Blisters prior to the manufacturer processchange. The Surveyor had pointed them to me during the survey however, sincethe purchase of the boat was in the middle of the season his recommendation wasto deal with them when the summer is over (when most of the boats are hauledout for the winter).


I had a great summer with my new boat on the Chesapeake River. The winter came and the boats was hauledout, Soda Blasted the bottom, then grinded all the blisters (300 – 400), shrinkwrapped the boat for the winter. In early spring, I Filled all Blisters, andused (x3) layers of Interlux 2000/2001 and (x2) layers of black bottom paint.


The boat was Blisters free for 16 years until it was sold in2016 and passed the Survey with flying colors. Blisters are really not a big dealto fix (almost Cosmetic) and I would pay more attention to boats with soft Spots in areas thatare not easy accessible to repair.

 

[localboy]

Google "blistology" by Steve D'Antonio and keep clicking through URLs for more information.

My 1970 Willard 36 had a crop of blisters when I purchased her in 1998 for which I received a decent survey credit at the time. Blisters numbered in the 100s and sized around a quarter to a couple inches. Many Willards have blisters but there is no known issue with structural integrity. I consider them to be cosmetic.

As part of a larger refit in Mexico, the blisters are being repaired on a case by case basis (vs peel and reglass). They may or may not reappear. I really don't care.

I don't know about Monks or even Taiwan trawlers of the era. But if you are bothered by blisters, don't buy a fiberglas boat. Below waterline blisters are fairly common.

Read articles from qualified experts such as Steve D and others he cites from the USCG. My. Impression is I accept blisters as a common flaw of fiberglass boats.

Thanks for the reference. I will read up on it. From some of the research I've already done it appears the opinions have changed/evolved over the decades. Originally, blisters were considered a death sentence but now seems the philosophy has changed to they are quite common and mostly cosmetic, as you mentioned. Unless they are large (over 4") and plentiful. Then the possibility increases of them being an issue that needs serious attention.

 

[psneeld]

Blisters were common 40 years ago and not considered much, but much was unknown.

The real discussion should be about hydrolysis as yes, blisters are only a part of the discussion and nowhere near the problem hydrolysis is.

 

[High Wire]

Was this era boat built in Taiwan or Canada?

1991 was the transition year where production moved from Taiwan to South America to Nova Scotia
The first 3 digits of the HIN will tell.
NSY was Nova Scotia
Taiwan had several possible yards. OYS was popular in 1989-91

 

[localboy]

1991 was the transition year where production moved from Taiwan to South America to Nova Scotia
The first 3 digits of the HIN will tell.
NSY was Nova Scotia
Taiwan had several possible yards. OYS was popular in 1989-91

Mahalo. Good info for our continued search...

 

[warren]

Thanks for the reference. I will read up on it. From some of the research I've already done it appears the opinions have changed/evolved over the decades. Originally, blisters were considered a death sentence but now seems the philosophy has changed to they are quite common and mostly cosmetic, as you mentioned. Unless they are large (over 4") and plentiful. Then the possibility increases of them being an issue that needs serious attention.

Old thread but anyway. Small blisters 1/4” dia will be restricted to gelcoat. (considered pimples fix every time you haul and move on ) 1-2” dia will usually involve some laminate or are very old gelcoat blisters ignored for years. Haul the boat and fix
4”+ blisters will be involving laminate , don’t ignore , fix now. More than just a few and walk away if buying.
Here is link to. Short post and article from epoxy works the magazine for West Systems epoxy done by the tech director. He repaired blisters on his sailboat 3 times on 20+ yrs or ownership using all the best materials and methods. Repairs don’t last forever but need doing, in the same way you would not ignore wood rot on boats or houses for too long.
https://warren149.wordpress.com/2018/09/21/blister-repair/

 

[psneeld]

Well, .....maybe West isnt best.

I had horrible blisters and hydrolysis....repaired and perfect hull without a blister in 11 years.

 

[fryedaze]

If your Monk 36 was built in Taiwan it was built in the same yard as our 1989 Overseas MC 42. I don't know when the last 36 Monk was built there. Our boat didn't have any blisters when we bought it in 2010. Mainly because it was only in the water 5 months a year. We keep it year round in the water starting in 2010. June 2012 small dime and nickel size blisters showed up, maybe 200. I have watched them now for 10 years and they haven't increased in size or number. A good fiberglass guy told me to enjoy the boat and don't worry about it.