Blister Photo & Question

[Tom1340]

I just hauled 1986 heavy displacement, European sloop for purchase survey. It had been in water (Florida) about 30 months since last haul. There are about 30 of these blisters. Owner says 'no worry', just grind and fill them. Is a proper repair really that simple? Hull is solid, without core. (I hope there is a photo with this post.)

[Tom1340]

The blisters are quarter to half dollar size.

[sabray]

Have a qualified surveying do a laminate profile.. He should grind out 1 of the blisters and perform a density test moisture test and visual inspection of the laminate condition. With out that I would not touch this boat. Could be just a barrier coat failure but this would have me very concerned.

[Beersmith]

if they are that small then they are just gelcoat blisters. You can grind, wash, dry (be sure to dry as long as you can, and clean intermittently), fill, & fair and you will be fine. IF they go down below the first layer of glass, then you have a lot of work ahead of you.

[Tom1340]

Thanks Sabray and Beersmith,
I spoke to yard service manager where boat is located. He says "this is nothing for boats in south Florida. Next time you paint, just grind them out and fill em." I know there is risk in taking this guy's advice, as he probably has long relationship with the broker. But if this is the extent of blisters after 26 yrs in tropical waters, can there really be a serious problem under the gel coat?

Further hands-on investigation before closing on this deal will be difficult, as boat is 1000 miles away.
Tom

[bstreep]

Just grind them, dry them and fill 'em, then paint. I WOULD take the advice to look at one of them to see how deep they are, but they look like typical surface blisters. Do regular bottom jobs, and don't let them get too big in the future - and you will likely continue to have them.

[Bash]

Originally Posted by Tom1340

I just hauled 1986 heavy displacement, European sloop for purchase survey. It had been in water (Florida) about 30 months since last haul. There are about 30 of these blisters. Owner says 'no worry', just grind and fill them. Is a proper repair really that simple? Hull is solid, without core. (I hope there is a photo with this post.)

First of all, that's not a photo of a heavy displacement sloop. That's medium displacement at best. The rudder doesn't hang down like that from a full-keel hull.

Any boat built in 1986 is going to have blister problems. For some hulls the problems will be worse than others. If such problems freak you out, you may want to back out of this deal, even if it costs your deposit, and look for something at least a decade newer.

I can't imagine that your surveyor or the yard manager is seeing anything on that hull that they haven't seen a thousand times. You'll probable get better advice from them than from those of us, however experienced, who are looking at a single photograph.

[HappySeagull]

If its so easy, why didn't the owner do it? Or maybe he has and there they are again...

judging by the picture, I'd Run away.
You will be or at least risk sealing up the water by epoxy over and the blisters will return with the quicky job suggested. You will be popping blisters as long as you own the boat with the quicky job. I'd take a wood gouge chisel to one. They will carve right out not much malletting needed .... If it carves out easy and DEEP., you have your answer...If it drips a long time and/or doesn't get dry-really dry...you have your answer.

[Tom1340]

Thanks Bstreep and Bash,

Bash, this 38 footer may not qualify as heavy displacement, but at 24,000 lbs, I wouldn't want it to fall on my foot. .
Tom

[Beersmith]

As I said, I think those are very small and inconsequential blisters, they do need a proper grind and fill job though. My boat had serious blister issues, each one penetrating the first layer of glass and the size of small plates, about 90 of them in total. I would have loved to have these small blisters instead.

Check out this gallery to get an idea of the difference:

http://www.thequestforwindandwaves.com/?page_id=313

[barnakiel]

These look most similar with pox blisters as seen on a Valiant 40.

Posibly osmosis. Open one up see what is inside.

b.

[Tom1340]

Erick (Beersmith),
Interesting photos. What am I seeing in photo 6? Are the small holes drilled or are they result of osmotic damage? Was the blister "pocket" under the gel coat or inside the glass laminate? If the water is in the laminate, don't you need to completely open it up to clean and dry it?
By the way, your hull is really looking sharp.
Tom
Tom

[Cheechako]

Big Warning: Hard to tell for sure from the one pic, but those could just be the tip of the iceberg. The bottom appears (not sure) to have been worked on extensively from the lumps and bumps. It's possible the boat is a real wet hull with extensive blister problems in the past. I was told the same thing (by the broker and the yard manager was nodding his head) on a boat that looked a lot better than that. In the end, a couple years later i had the whole bottem removed to find hundreds of large, deep previous repairs and many new ones. The hull was so wet that I discovered it was blistering inside the bilge! Of course Yard managers see this all the time so to them it's not a big deal, just more money. But you dont have to buy a "blister boat". I've had boats built in the mid 80's with zero, nada blisters.. not sure where that comment was coming from...

[Celestialsailor]

The idea that a heavy displacement boat has to have a full keel with a keel hung rudder is just plain silly. A Valiant 40 is heavy displacement as is a Kelly Peterson 44. Secondly some boats have blisters and some never get them. My hull is a 1974 and blister free. There are new boat that get blisters after a few years. So to label a certain year is a broad brush stroke...at best.
As far as the OP...get a proper survey. Blisters can bite you in the @ss later on.

[Cheechako]

"proper" being the key word when it comes to surveys..... the above mentioned boat was surveyed. You want someone who is "inquisitive" not a "form filler".