NOT Osmosis problem?

[goeasy123]

What's the best way to fix this problem?

My boat had an epoxy barrier coat put on the hull a few years ago. The epoxy seems to have gassed off leaving little osmosis-like bubbles in the barrier layer. It doesn't go through to the gel coat. but it look unsightly and might eventually have an effect on the underlying gel.

[Bill O]

Originally Posted by Andy Todd

What's the best way to fix this problem?

My boat had an epoxy barrier coat put on the hull a few years ago. The epoxy seems to have gassed off leaving little osmosis-like bubbles in the barrier layer. It doesn't go through to the gel coat. but it look unsightly and might eventually have an effect on the underlying gel.

Basically you have paint bubbles filled w/water. Are they many or just a few bigger ones? IMO if on the hard, would circle the location (sharpie) of the bubble, pop them, rinse w/fresh water, let them dry out then recoat the specific bubble spots w/the same epoxy barrier. Follow instructions for proper cure time.
Its possible the barrier wasn't cured well before the addition of antifoul or launching, thus creating bubbles. Paint/water bubbles are sometimes also seen in hard (non-ablative) antifoul.


Bill O.

[boatbroke]

Hi Andy_Todd,

Normally when Epoxy primer is applied there will be minimum 3 coats.

If they have been done too quickly there can be some small out gassing as the thinners in the paint underneath try to escape through the layer(s) above that have already 'skinned' off.

Sometimes if it was applied in the rain a similar pattern can be seen.

Most probably be fine, perhaps ask the yard who applied it to fix it?

Or a good hard sand to get the antifoul off next slipping and a couple more coats of epoxy again.

Shame, a lot of work goes into prepping the bottom for something to go wrong that sucks!

Good luck with it!

[goeasy123]

Originally Posted by boatbroke

Hi Andy_Todd,

Normally when Epoxy primer is applied there will be minimum 3 coats.

If they have been done too quickly there can be some small out gassing as the thinners in the paint underneath try to escape through the layer(s) above that have already 'skinned' off.

Sometimes if it was applied in the rain a similar pattern can be seen.

Most probably be fine, perhaps ask the yard who applied it to fix it?

Or a good hard sand to get the antifoul off next slipping and a couple more coats of epoxy again.

Shame, a lot of work goes into prepping the bottom for something to go wrong that sucks!

Good luck with it!

It was evident when I bought the boat and it hasn't got any worse. What you say is what my surveyor said, but he didn't proffer any solutions.


It is a shame. The yard and the owner took pride in the job and provided me with pictures for the whole process.



The yard is 500 miles away and not on a route we plan to take. We're on a slooooow circumnavigation.


Thanks

[slug]

Contact a surveyor and have him perform a moisture content test on the underwater laminate

[goeasy123]

Originally Posted by slug

Contact a surveyor and have him perform a moisture content test on the underwater laminate

Already done. He was able to identified that the moisture was only the exopy coating deep.... good news.