Osmotic blisters

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TomW1
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Re: Osmotic blisters

Post by TomW1 » Mon Jul 30, 2018 5:11 pm

Fallguy how big an area is this covering I don't like this at all. I have worked on all kind of restorations while I lived in Cleveland and Boston it was my relief from in a high powered corporate job. First thing I would do is pop those bubbles and see if there is any moisture under them. Next sand them down even with the current fiberglass. If you sand the fiberglass off with the bubbles then you need to go further and sand down to the hull and get rid of the gelcoat.

Boston Whalers are notorious for this. One of the first things I did on the forum was help a member rebuild his BW, stringers and frames and deck.

Well what ever you do, good luck.

Tom


Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

fallguy1000
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Re: Osmotic blisters

Post by fallguy1000 » Mon Jul 30, 2018 6:11 pm

Brown goo man.

I really wonder if my heat lamp idea migrated some moisture...and then it is trying to equilibrium now...

Time to grind, but I almost need to see if more will pop ???????
My boat build is here -------->

viewtopic.php?f=12&t=62495

fallguy1000
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Re: Osmotic blisters

Post by fallguy1000 » Mon Jul 30, 2018 6:11 pm

Brown goo man about 2' section on aft hull star side.

I really wonder if my heat lamp idea migrated some moisture...and then it is trying to equilibrium now...

Time to grind, but I almost need to see if more will pop ???????
My boat build is here -------->

viewtopic.php?f=12&t=62495

fallguy1000
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Re: Osmotic blisters

Post by fallguy1000 » Mon Jul 30, 2018 6:13 pm

Could be worse. Might have happened after I finished the new paint job.
My boat build is here -------->

viewtopic.php?f=12&t=62495

OrangeQuest

Re: Osmotic blisters

Post by OrangeQuest » Mon Jul 30, 2018 8:02 pm

fallguy1000 wrote:
Mon Jul 30, 2018 6:11 pm
Brown goo man about 2' section on aft hull star side.

I really wonder if my heat lamp idea migrated some moisture...and then it is trying to equilibrium now...

Time to grind, but I almost need to see if more will pop ???????
Can you maybe dissect a little of the sub-surface at one of the blisters? Is the brown goo more oil based or water base?

thb
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Re: Osmotic blisters

Post by thb » Tue Jul 31, 2018 6:19 am

I think the clue on what is causing this, who installed the 6 oz cloth and epoxy outer coating.. Someone during the boats history sanded down the gelcoat. You said it was thin with some paint in places. They then added the 6 oz cloth and epoxy as a barrier coating.
Why did they do this?
Do you know the history of the boat?
Was it used as a yacht tender at some stage of its previous life?

I had a brand new 36 ft sportfisherman built for me in Taiwan back in 1991 and after less than one year in the warm Hong Kong waters, it had osmosis blisters. It does not take long sitting in the water to them to develop. I am speaking from experience my friend.

Regards
Tom in Steinhatchee

fallguy1000
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Re: Osmotic blisters

Post by fallguy1000 » Tue Jul 31, 2018 9:28 am

I am about 90% sure the moisture got in there from my heat lamp drying of the transom wood.

The location is really the clue.

So, I have a wee bit of moisture.

Maybe I will just cut some holes in the hull and let it try to dry out in my heated building this winter.

I did all the glass skinning to hide the alligators and gelcoat crazing.
My boat build is here -------->

viewtopic.php?f=12&t=62495

OrangeQuest

Re: Osmotic blisters

Post by OrangeQuest » Tue Jul 31, 2018 7:03 pm

Here is an interesting read on your blister issue: http://www.nauticalweb.com/info/maint/osmosi_e.htm
I had to look it up cause I didn't know what they were.

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