Blisters, again

[a64pilot]

Originally Posted by minaret

Did you have a knowledgeable surveyor take moisture meter readings of the bottom? I doubt it, as a bottom paint removal is required to get accurate readings. You can get an idea by grinding the paint off down to Gelcoat in a couple of places and taking readings. You can have severe hydrolysis and saturation with no blisters showing, it's the only way to know the state of the laminate for sure. Solid bottom?

It's an 87 Island Packet, so yes solid glass hull, no we didn't get any moisture readings as bottom paint would give false readings.
Saw a receipt from 2011 that said stripped bottom to bare hull, repaired blisters as necessary and applied Interlux barrier coat and bottom paint.
I gotta think the barrier coat was an attempt to end the blistering, for some reason it didn't, but for all I know it did work except for a few areas.

[minaret]

Originally Posted by a64pilot

It's an 87 Island Packet, so yes solid glass hull, no we didn't get any moisture readings as bottom paint would give false readings.
Saw a receipt from 2011 that said stripped bottom to bare hull, repaired blisters as necessary and applied Interlux barrier coat and bottom paint.
I gotta think the barrier coat was an attempt to end the blistering, for some reason it didn't, but for all I know it did work except for a few areas.

Classic. No active drying billed for, no six months of lay days for dry time. This was a quick and dirty so they could sell the boat. We have clients ask for this often, especially brokers, and won't do it. Caveat emptor. Where else did they cut corners? Ask for pictures of the meter readings of the bottom prior to coating. If they don't have any, walk. If you are ever tempted to coat a bottom which is not dry with anything, save yourself some headache and just burn a big pile of hundreds instead.

[a64pilot]

Surveyor had indicated that in his opinion that the barrier coat was likely to be the problem as they had probably sealed moisture in and it was this moisture that was sealed between two impermeable layers that was the problem.
I'd like to do a quick and dirty repair and bottom coat, enjoy the boat for a couple of years and pull her down in a few years for a complete re-fit at that time before we retire and go cruising.
Sounds like when I have a bottom job done that she should sit on the hard for a few days after stripping several areas down to gel coat, get moisture reading and based on those readings determine if a quick and dirty is acceptable for a few years?

[minaret]

Originally Posted by a64pilot

Surveyor had indicated that in his opinion that the barrier coat was likely to be the problem as they had probably sealed moisture in and it was this moisture that was sealed between two impermeable layers that was the problem.
I'd like to do a quick and dirty repair and bottom coat, enjoy the boat for a couple of years and pull her down in a few years for a complete re-fit at that time before we retire and go cruising.
Sounds like when I have a bottom job done that she should sit on the hard for a few days after stripping several areas down to gel coat, get moisture reading and based on those readings determine if a quick and dirty is acceptable for a few years?

Exactly what I'd do. I'd be comfortable doing that at anything less than 20% relative on the old GRP-33. Any higher would concern me.

[F51]

Blisters are ugly, no doubt about that. But has anyone ever heard of a boat being lost due to blistering? I do think that some yards use fear to sell barrier coats.

[a64pilot]

Originally Posted by minaret

Exactly what I'd do. I'd be comfortable doing that at anything less than 20% relative on the old GRP-33. Any higher would concern me.

Thanks, sounds like a plan

[a64pilot]

Originally Posted by F51

Blisters are ugly, no doubt about that. But has anyone ever heard of a boat being lost due to blistering? I do think that some yards use fear to sell barrier coats.

Of course they do, fear sells the best, that and snobbery. Often times preventative maintenance is cheaper in the long run, I'm trying to determine as I have very little experience is this something that I need to get on top of right away as if I don't it's going to get expensive, or can it wait for awhile

[Cheechako]

Well... there's something to be said for ignoring some problems. It's just hard for me to do... I'd spend all my time thinking it's getting worse! But yeah, until a full strip and epoxy is done, why not? fill in the big stuff and paint 'er over and go sailing... I doubt a couple years will end the world.
I once bought a boat that had had the same thing done. No blisters at survey. 3 years later it was saturated.. probably was the whole time.

[HappyMdRSailor]

Originally Posted by minaret

Exactly what I'd do. I'd be comfortable doing that at anything less than 20% relative on the old GRP-33. Any higher would concern me.

There ya have it.... "If so... Then Go!!!"

Originally Posted by a64pilot

Thanks, sounds like a plan

Originally Posted by Cheechako

Well... there's something to be said for ignoring some problems. It's just hard for me to do... I'd spend all my time thinking it's getting worse! But yeah, until a full strip and epoxy is done, why not? fill in the big stuff and paint 'er over and go sailing... I doubt a couple years will end the world.
I once bought a boat that had had the same thing done. No blisters at survey. 3 years later it was saturated.. probably was the whole time.

Yepper... my continuing opinion all along... And remember when it's time... a REAL barrier coat doesn't come in one can with a lid...

[klmmicro]

Originally Posted by HappyMdRSailor

Yepper... my continuing opinion all along... And remember when it's time... a REAL barrier coat doesn't come in one can with a lid...

I always thought "barrier coat" was a layer of resin, not a paint. To me, the paint was always just for anti-fouling...being Navy, we painted the hell out of everything and NEVER called it a "barrier".