Blisters Visible to Diver?

[Tom1340]

A boat I'm interested in had blisters when surveyed last spring. The blisters were filled and the boat resplashed. I'm still interested in the boat, but first need to know the current situation below the waterline. Is a diver able to inspect for blisters while in water? Or, will the guy who does the routine bottom cleaning be aware if the blisters have reformed? I don't doubt that blisters will eventually recur and that could be okay, but it's not okay if they are fast and aggressive. Thanks for comments. Tom

[ReMetau]

I think it depends on the size of the blisters and the visibility of the water, but in most cases I would think that blisters would not be visible.

[propellanttech]

Originally Posted by Tom1340

A boat I'm interested in had blisters when surveyed last spring. The blisters were filled and the boat resplashed. I'm still interested in the boat, but first need to know the current situation below the waterline. Is a diver able to inspect for blisters while in water? Or, will the guy who does the routine bottom cleaning be aware if the blisters have reformed? I don't doubt that blisters will eventually recur and that could be okay, but it's not okay if they are fast and aggressive. Thanks for comments. Tom

If the bottom received a new barrier coat, and bottom paint, theoretically there shouldn't be any new blisters. If there are, the actions were performed incorrectly. I would think a basic bottom job would last at least a year.

But I may be misinformed.

On the other hand, I would have a boat hauled for possible damage since the last survey, that may not be visible to a diver. (Strut, shaft, hardware, etc.)

James L

[S/V Illusion]

If you are really interested in buying it, you will need to have it hauled to inspect for delamination of the hull and rudder anyway so this seems like a moot issue.

[Vasco]

If the blisters were just filled you still have an osmosis problem. They will return unless the bottom is done properly. Peel, dry, fill, barrier coats. It will be difficult for a diver to determine the blister state of the bottom. You really need to measure it with a moisture meter.

[Rakuflames]

Originally Posted by Tom1340

A boat I'm interested in had blisters when surveyed last spring. The blisters were filled and the boat resplashed. I'm still interested in the boat, but first need to know the current situation below the waterline. Is a diver able to inspect for blisters while in water? Or, will the guy who does the routine bottom cleaning be aware if the blisters have reformed? I don't doubt that blisters will eventually recur and that could be okay, but it's not okay if they are fast and aggressive. Thanks for comments. Tom

Divers cannot always see the blisters. Did it have a lot of blisters when hauled?

[Rakuflames]

Originally Posted by propellanttech

If the bottom received a new barrier coat, and bottom paint, theoretically there shouldn't be any new blisters. If there are, the actions were performed incorrectly. I would think a basic bottom job would last at least a year.

But I may be misinformed.

On the other hand, I would have a boat hauled for possible damage since the last survey, that may not be visible to a diver. (Strut, shaft, hardware, etc.)

James L

A couple of certified marine surveyors spoke at our club, and they made two points:

!) it's really hard and takes a long time to REALLY rid a boat of blisters and

2) no boat has ever sunk because of blisters.

If there are a LOT of blisters, however, it can slow your boat down the way a dirty bottom can.

[propellanttech]

Originally Posted by Rakuflames

A couple of certified marine surveyors spoke at our club, and they made two points:

!) it's really hard and takes a long time to REALLY rid a boat of blisters and

2) no boat has ever sunk because of blisters.

If there are a LOT of blisters, however, it can slow your boat down the way a dirty bottom can.

Funny,

I see this like acne. It's not fatal, but no one wants it.

Still, I'm concerned with the method of the repair. If the previous owners did this improper, what other things were done with the same finesse?

Big red flag to me......but I'm more critical than most.

James L

[Rakuflames]

Originally Posted by propellanttech

Funny,

I see this like acne. It's not fatal, but no one wants it.

Still, I'm concerned with the method of the repair. If the previous owners did this improper, what other things were done with the same finesse?

Big red flag to me......but I'm more critical than most.

James L

As I understand it, to REALLY get rid of blisters the boat has to be out of the water for months, so they are very rarely "really fixed." Some blisters are potentially serious, but most are not, and I really do think someone could do a good job on a boat but draw a line at the expense of having the boat out of the water for months to air-dry the bottom.

What I've been told (my boat only had three) is that there are other ways to deal with most blisters, but with no guarantee that they will not return.

[propellanttech]

Originally Posted by Rakuflames

As I understand it, to REALLY get rid of blisters the boat has to be out of the water for months, so they are very rarely "really fixed." Some blisters are potentially serious, but most are not, and I really do think someone could do a good job on a boat but draw a line at the expense of having the boat out of the water for months to air-dry the bottom.

What I've been told (my boat only had three) is that there are other ways to deal with most blisters, but with no guarantee that they will not return.

I understand there are sometime compromises when it comes to time. My question is; do you(the person looking at the boat) think the repair was within reason to what you consider appropriate for the situation?

This is about the concerned parties feelings, for he/she will be the one to experience the possible re-occurrence of blisters.

If they feel the blisters are a less than likely a non-critical situation, then their presence is not important. Just know blisters are possible on the next haul out. A haul out will eventually be needed anyhow.

On that same line of thought, I wonder if anyone has tried vacuum drying of a hull with blisters removed. Sounds like it would be much less time.

James L

[minaret]

Hotvac. Do a forum search.

[propellanttech]

Originally Posted by minaret

Hotvac. Do a forum search.

Ok, so I was right........interesting reading.

James L

[Bash]

Originally Posted by Rakuflames

Divers cannot always see the blisters.

Agreed. The best way to survey for blisters is with a sander. A diver is usually only going to notice the real nasty blisters.

[Cheechako]

I t hink you ar e on the right track. If the blisters can be seen again already, then the boat has a bad case of osmosis....run! If not, then may be worth a haul and survey... how long has it been?
I once had a boat with glass so saturated (and it was 1.25 thick in the bilge under the floorboards) it had blisters in the bilge/under the floorboards on the inside! Some boats have minor blisters, some boats have big problems that will follow you the whole time you own her.... be careful!

[Tom1340]

This 25 year old boat had 40 to 50 'quarter' size blisters 7 months ago, which were individually filled at that time. Filling blisters may not be a best practice, but it is a common practice in FL. I have no doubt that blisters will eventually return and require rework. But if they return in 6 or 7 months, thats a little too aggressive for me.
I don't want to spend another small fortune to go through a haulout, so I'm hoping to short cut the process by using a diver for a preliminary assessment. Other than some issues below water line (blisters being the most significant) this boat has been well maintained by the owner (opinion of surveyor).
Is there anyone out there who's successfully used a diver to check blister status?
Thanks all for your comments.
Tom