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Old 09-06-2024, 18:25   #1
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Pitting/cratering (osmosis?) repair

Backstory...I acquired this boat this past November. It was and is on the hard in a boatyard, for about a year before I picked it up. While scraping/sanding the bottom, I was pleased to find coppercoat, until I took a closer look at the condition of the coppercoat. The stabbord side has much pitting/cratering which is about as deep as the paint, with some areas showing the glass (in good shape) underneath. Pictures attached.

What I'd like to do is to fair the hull giving it a fresh, smooth appearance. I could sand the entire hull, removing all paints. Or, could I get by with fairing the cavities and coating with a barrier coat before I finish with an albative paint? What would be your recommendation for a DIY project?

The boat is a 1978 Pearson 323 in good/decent condition and I'd like to keep her about 5 years or so, with a decent resale value.
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Old 09-06-2024, 21:25   #2
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Re: Pitting/cratering (osmosis?) repair

Is that black paint under the "copper coat" ? ... Hard to tell from a photo but what makes you think that is copper coat ?
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Old 10-06-2024, 00:43   #3
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Re: Pitting/cratering (osmosis?) repair

If this is coppercoat, no convinced it is, it is a nightmare scenario. Option 1 slap ablative antifouling on as is and wait until the coppercoat erodes further. Option 2 wet sand to remove the coppercoat and start afresh. Dry mechanical removal is very very difficult as the coppercoat is hard and breakthrough occurs suddenly damaging the hull beneath.
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Old 10-06-2024, 06:38   #4
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Re: Pitting/cratering (osmosis?) repair

Quote:
Originally Posted by boatpoker View Post
Is that black paint under the "copper coat" ? ... Hard to tell from a photo but what makes you think that is copper coat ?
I can't say for certain that it's coppercoat since I have no knowledge of the boat in years past, other than documentation that exists onboard. But...I've been told that it is coppercoat. With that said, there was black antifoul (Trinidad Pro) on top of the copper colored sealer. The black paint that you're seeing is whats been left behind from the sanding/scraping. The hull was pitted in areas before the black antifoul was applied, apparently.
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Old 10-06-2024, 06:51   #5
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Re: Pitting/cratering (osmosis?) repair

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Originally Posted by Tupaia View Post
If this is coppercoat, no convinced it is, it is a nightmare scenario. Option 1 slap ablative antifouling on as is and wait until the coppercoat erodes further. Option 2 wet sand to remove the coppercoat and start afresh. Dry mechanical removal is very very difficult as the coppercoat is hard and breakthrough occurs suddenly damaging the hull beneath.
Thank for this. I was afraid that this would be a nightmarish effort to remove. Obviously, the copper colored paint was deteriorating when the PO antifouled the hull, leaving behind the cratering that you see in the pictures.

I can't be convinced of coppercoat, also, since I have no former documentation or knowledge of the process. Assuming that it is, is there a way to fair the hull after being pressurewashed and solvent cleaned while in this state?

I'll do a few test areas of different removal methods.
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Old 10-06-2024, 07:33   #6
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Re: Pitting/cratering (osmosis?) repair

With the palm of your hand rub on the copper coloured area vigorously then show us a photo of your palm.
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Old 13-06-2024, 10:36   #7
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Re: Pitting/cratering (osmosis?) repair

UPDATE on this question. After numerous days and effort to feather sand the what I thought was Coppercoat. I gave up and finally did an acetone test removal.

Soaking a towel in acetone and taping it, sealed w plastic, to a test area of the hull for 30 minutes. After removing the plastic and scraping, I cleared about a square foot of paint from the hull....effortlessly.

Ok, I've got a method to remove this stubborn AF paint from my hull. But why on earth would this paint not be affected with 40 grit on an osilating sander???
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Old 13-06-2024, 10:40   #8
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Re: Pitting/cratering (osmosis?) repair

If you'd done the palm test I suggested I may have an answer for you.
I guess you are not interested so no comment from me.
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