Blister Photo & Question

[forsailbyowner]

Hull Blisters on Boats and Yachts - by David Pascoe, Marine Surveyor


This site goes into detail on the subject

[Bash]

Originally Posted by 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.

The displacement/length ratio of a Valiant 40 is 255.56. According to the US Sailing calculator, linked below, that puts it in a "Moderate Displacement" category.

D / L Ratio

While you're there, you may want to do the math on the Kelly Peterson 44. It comes out at an even lower 230.17, which US Sailing also lists as "Moderate Displacement."

Just plain silly?

[Tim Godber]

These blisters are just like those on my Little Harbor 46, I bought it last year aware of the problem. To the poster from Southern Florida, it doesnt always happen, my 89 Sabre was fine when I bought it there, the Little Harbor was probably fine until the last owner bought it 7 years ago, I can see from the dates of sale, survey lift, epoxy treatment and relaunch that all the above happened in a week or two, so the treatment was the problem, it locked in moisture. Grinding and filling may not be enough, you should have a proper survey, dry out after peeling, then only after the surveyor has checked PH and moisture levels, put 6 layers of gelshield. Or in your case walk away!
As to heavy displacement, my LH is 22 tons and has just such a keel! Lovely Boat!

[Tom1340]

Yes, the surveyor... good guy with respectable qualifications. I feel I received value for the price charged. But I cannot describe him as aggressive. In hind sight, I wished he'd said, "let's pop one of these babies and see what's under it". If any body knows a top notch surveyor in the Punta Gorda area of Florida, let me know so I can get a 2nd opinion.
Tom

[Cheechako]

You could ask the seller to sign an affidavit saying there have been no blister repairs in the past. I did that once! Wow, everyone cringed! That will tell you a lot!
Was the seller there when the boat was out of the water? Did you ask him right out if he's had a history of blisters? It's amazing if you can spend some time with a seller, you start asking things and that leads to other things etc etc.. Brokers hate it. Use the excuse that you want to sort out some questions about the boat etc. One boat I bought in Florida there was some standard form that asks the seller to certify there is no hidden damage, just curious....did that go away? Was this due to the rash of hurricane damaged boats...?

[Celestialsailor]

Originally Posted by Bash

The displacement/length ratio of a Valiant 40 is 255.56. According to the US Sailing calculator, linked below, that puts it in a "Moderate Displacement" category.

D / L Ratio

While you're there, you may want to do the math on the Kelly Peterson 44. It comes out at an even lower 230.17, which US Sailing also lists as "Moderate Displacement."

Just plain silly?

Yes...you are just plain silly. Want a second opinion? Your mother dress's you funny...

[Tom1340]

This link provided by forsailbyowner is quite informative.
Thanks,


"Hull Blisters on Boats and Yachts - by David Pascoe, Marine Surveyor

This site goes into detail on the subject"

[Cheechako]

One thing that doesnt get mentioned much is the mental state a bad blister boat puts you in! You work your a** off for a month grinding and prepping and filling etc. Launch the boat. 6 months later the bottom scrubber mentions you have a "few under there". You go cruising. Scrubbing your bottom in paradise you notice they are showing up every where, "gee... wonder how deep those are?" etc etc.... When you to get to a baotyard area in paradise you are still trying to solve the problem.... it's the pits. As mentioned above, you dont have to buy a boat with blisters!

[Tom1340]

I've done a lot of research on blisters since starting this thread. It took a while to find useful info. Here are links to two of the best resources. Maybe this will be useful to someone else in the future.
Boat Hull Blisters: Blisters Again?

http://www.westsystem.com/ss/assets/...Prevention.pdf

[Cheechako]

interesting writing in the first link. I'm not sure where the facts are on what boat or type of construction has or doesn't have blisters.....? He seems to mention something as though it is fact and then challenge you to prove him wrong. Still.... some good reading for sure.
It would be very interesting to have a nationwide poll on actual experiences, date of build, location of build and maybe severity of the blisters on scale of 1-5.

[minaret]

Personally I believe recurring blisters are often the result of the almost universal habit of dishing out a blister and then just filling it with epoxy filler and barrier coating over. We would never do this in our yard, it's just not proffesional (although many pro yards still do it this way because they have a short warranty and it's quicker). We dish out each blister and then glass them back up with alternating lams of DB1708 and CSM, finishing with a few layers of CSM rolled out fair but just a little high. Then we grind fair. So there is no fairing compound below the waterline unless its a double peel and then its just a thin slick over the whole bottom. I believe filling a blister more than about an 1/8" deep is a certain recipe for solvent retention followed by vapor popping and blisters. These blisters are caused by the solvent retention eating the fairing compound, not by osmosis. This is why you will get recurring blisters even under 2000e if you use this common technique. Having ground into hundreds of boats in all stages of the blister process, including the many warranty jobs we did in the old days before we dialed in the recipe, I'm quite sure this is the case. I have seen it many times. A boat with a preexisting bottom job with barrier coat will come in, the owner cursing whoever did the job last for applying the barrier coat incorrectly. Then I peel it and it's immediately clear that every single blister is in a previously repaired spot that was just filled. This is one reason we have a ten year warranty and haven't done a single bit of warranty work in the last ten years. The other is of course the hotvac.

[speedoo]

So OP, where do you stand with this boat? I see too many warning signs of a potentially very expensive repair:

1. In the only photo I can see there are about 30 blisters just on the starboard side around amidships. If the rest of the boat is like that, you have a situation that is probably pox, meaning the gelcoat, and possibly some of the fiberglass has been penetrated.. If you want to pursue the boat, it had better be a great deal, and you MUST have it surveyed by the best surveyor you an find, and you must have the condition of those blisters and the wetness of the bottom accurately analyzed.

2. Worst case, probably unlikely, is that the hull structure has been so badly damaged that the boat is basically worthless except for scrap.. Much more likely is that the gelcoat and some glass will have to be peeled. Depending on how deep the peel goes and how much hull thickness is left, some reglassing of the entire underbody may be necessary. But whether or not reglassing is needed, the hull will need to be dried, which probably means an extended and expensive stay in a yard.. Except for the reglassing, I speak from experience.. Then of course you will need to barrier coat and paint the bottom.

Don't think for a minute you can trust anyone but your own surveyor, and only trust him if he has superb references.


Trust me, you need to be very careful with this boat.

[Tom1340]

Minaret, thanks for adding to my knowledge of blisters. It is a complex and interesting problem.
Speedo, My surveyor did not open the blisters. So I offered to pay yard fees to keep the boat on hard until I could arrange for an inspection of the blisters. Instead, the owner had them filled and repainted the bottom. I do not know if this was because of bad communication or bad intent, but I rejected the boat two weeks ago.
If I can convince myself that the owner had misunderstood my request, and if I can figure out how to evaluate the hull under a new coat of paint, then I may make another run at this boat. In the meantime, I'm cruising yachtworld instead of cruising a yacht.
Tom

[speedoo]

Originally Posted by Tom1340

Minaret, thanks for adding to my knowledge of blisters. It is a complex and interesting problem.
Speedo, My surveyor did not open the blisters. So I offered to pay yard fees to keep the boat on hard until I could arrange for an inspection of the blisters. Instead, the owner had them filled and repainted the bottom. I do not know if this was because of bad communication or bad intent, but I rejected the boat two weeks ago.
If I can convince myself that the owner had misunderstood my request, and if I can figure out how to evaluate the hull under a new coat of paint, then I may make another run at this boat. In the meantime, I'm cruising yachtworld instead of cruising a yacht.
Tom

Hard to see how there was any miscommunication, you have to be very suspicious of the owner's action. I repeat, the only person you can trust is a
thoroughly checked out and very competent surveyor.. I would only make another run at that boat if you are well armed with a surveyor who has a plan to accurately evaluate the bottom. I can recommend one in Ft. Lauderdale that I hear is worth checking out.

[David_Old_Jersey]

Originally Posted by Tom1340

Minaret, thanks for adding to my knowledge of blisters. It is a complex and interesting problem.
Speedo, My surveyor did not open the blisters. So I offered to pay yard fees to keep the boat on hard until I could arrange for an inspection of the blisters. Instead, the owner had them filled and repainted the bottom. I do not know if this was because of bad communication or bad intent, but I rejected the boat two weeks ago.
If I can convince myself that the owner had misunderstood my request, and if I can figure out how to evaluate the hull under a new coat of paint, then I may make another run at this boat. In the meantime, I'm cruising yachtworld instead of cruising a yacht.
Tom

As a Vendor that probably made most sense - even at the cost of losing you as a buyer. At least now the boat won't have any blisters (at least for a while!) - and the new buyer just gets to take part in the same crapshoot we all do. and you will on the next boat.....I guess one advantage in buying a boat with blisters is that a) you know the Vendor hasn't bodged a job to sell and b) is reflected in the price (or at least a chunk of)........but I would still prefer a boat without!