thousands of bottom blisters

[bkrizmanic]

I had the exact same thing, as I ran the sander over the bottom the blisters just started showing up, none went past the gelcoat, at some point in time one of the PO's put a barrier coat over the bottom paint trapping moisture between the paint layers.
I tried to find what others did, never found much on line really, lots of opinions, I talked to a boat builder and took his suggestion, I took it down to the gelcoat, three coats of epoxy barrier coat and then my bottom paint. Worked out well, he also said if any went past the gelcoat to sand to the fiberglass, couple coats of epoxy then barrier coat.

[boatpoker]

Originally Posted by Tillsbury

Wow, boatpoker, I didn’t realise you were new here

Yeah , I know but this guy in particular selling his magic box snake oil gets under my skin. I'll get over it

[fstbttms]

Originally Posted by Sailing4Jesus

Older GRP Hulls were built using the only Epoxy Catalyst that was available back then. Unfortunately, that Catalyst never stops hardening which gives of a gas that causes the Hull Blisters, meaning YES THE Blisters will return for the life of the boat...

When you think you've heard it all...

[Cadence]

Originally Posted by boatpoker

As a Certified Marine Corrosion Analyst, this is the most bizzare, irrational nonsense I have read on this forum

Amen!

[Baba Buoy]

Only an issue when buying or selling boat. Ignore them.

[Jmstee]

Thankyou for all the suggestions Im going simple; sand now then barrier coat in the spring and repaint. Then pretend there was never an issue and enjoy sailing.

[boatpoker]

Originally Posted by Jmstee

Thankyou for all the suggestions Im going simple; sand now then barrier coat in the spring and repaint. Then pretend there was never an issue and enjoy sailing.

The right decision...... Enjoy spring sailing

[double u]

Originally Posted by Corrosion-Eng

Hi,
The CAUSE is stray current creating electrolysis. Current is flowing from your vessel via the water to the Earth. It can be stopped. Then the bubbles will stop. Google search for "how to stop stray current". Click on "How to prevent marine stray current".


There is a movie with before and after also photos on Fast Track.


Corrosion-Eng

...luckily however we can solve the problem by wearing tinfoil hats.
(you are a marine service provider, corrosion Eng, & this is the state of your knowledge? This is bordering on the criminal! People sail their boats over oceans, you know...)

[Uncle Bob]

Originally Posted by Sailing4Jesus

Older GRP Hulls were built using the only Epoxy Catalyst that was available back then. Unfortunately, that Catalyst never stops hardening which gives of a gas that causes the Hull Blisters, meaning YES THE Blisters will return for the life of the boat, but its a Slow Process. Other than Pealing The Hull, (A Very Costly Endeavor) your best bet is as many here have already advised you. The Hull will probably need to be buried about Three Hundred Years from now, so sand it out as best as you can, then check with the engineers at AwlGrip as they will be your best source of whatever EPOXY PAINT you should Repaint the Hull with. Then do as all sailors do by Weighing Anchor, Setting Sails, and GO, GO, GO...

SEnior Chief, USN, RETIRED

Originally Posted by Corrosion-Eng

Hi,
The CAUSE is stray current creating electrolysis. Current is flowing from your vessel via the water to the Earth. It can be stopped. Then the bubbles will stop. Google search for "how to stop stray current". Click on "How to prevent marine stray current".


There is a movie with before and after also photos on Fast Track.


Corrosion-Eng

Some threads seem to just bring them all out!

[double u]

Originally Posted by Uncle Bob

Some threads seem to just bring them all out!

& one is even a “Marine Service Provider“! Which “service“ can he possibly provide? BS dispensing?

[Cadence]

Originally Posted by double u

& one is even a “Marine Service Provider“! Which “service“ can he possibly provide? BS dispensing?

Not to piss off anyone. Epoxy catalyst in days of yore never stop hardening and giving of gas? Polyester and MEK peroxide and that is questionable?

[rbk]

Originally Posted by Cadence

Not to piss off anyone. Epoxy catalyst in days of yore never stop hardening and giving of gas? Polyester and MEK peroxide and that is questionable?

I think they were referring to ‘corrosion-eng’ as they are listed as a marine service provider and not boatpokers comment.

[Cadence]

Originally Posted by rbk

I think they were referring to ‘corrosion-eng’ as they are listed as a marine service provider and not boatpokers comment.

I didn't see boatpoker said anything questionable. It was strictly the epoxy and catalyst comment. Blistered boats were polyester with MEK peroxide.
I would have to agree with uncle bob. Maybe it's a little bit of knowledge is dangerous.

[rbk]

Originally Posted by Cadence

I didn't see boatpoker said anything questionable. It was strictly the epoxy and catalyst comment. Blistered boats were polyester with MEK peroxide.
I would have to agree with uncle bob. Maybe it's a little bit of knowledge is dangerous.

Yes but bob had said ‘epoxy catalyst’ caused the blisters in hulls referring to the use of an amine based hardener (most common for epoxy but there are many) MEK won’t cure epoxy and visa versa so the statement was off a little.

[rbk]

Looking back it wasn’t uncle bob that even wrote the comment it was sailing4jesus. I think we’re on different pages. Bob also brought light to the epoxy comment.