Odd paint problem

[Larry Meyer]

I’m having an odd paint problem on an Ogilvy I rebuilt oh, 12 years, ago. For the past 2-3 years, whenever I scrape bottom, the paint wants to peel off in substantial chunks. Previously, scraping a rock or something, it would scratch or scrape the paint, indicating a good bond between paint and filler. Now it seems like I could peel all the paint away from the filler with a good tug.

I used Rollin’s filler and a traditional Interlux marine enamel.

Has this happened to anyone else? I assume there’s no cure, except a repaint.

 

[jvanleir]

I think you would have to repaint. If you were up to it, there is a way to mix a coloring into the filler so that paint is not needed or less visible if scratched. You could also try some different brand paints.

 

[Rollin Thurlow]

Larry,
I don't recall ever having that problem and it does sound a bit odd. Just as a guess I might suggest that the canvas is getting old or has been stored wet and warm for long periods and the canvas is showing the first stages of rot. If that was the case, the canvas under the filler would be turning black and it should tear really easy. But you didn't mention a tearing problem so hopfully its not that at all.
Its got me stumped for right now. Maybe some others will have suggestions.

 

[Larry Meyer]

Thanks for thinking about it. Canvas rot may be a factor. I haven’t looked real close but there are no other obvious signs of canvas rot.

In one respect, it’s almost as if the physical characteristics of the paint have changed: it’s become slightly “rubberized” or elastic and will stretch, instead of chip or tear. Failure of the bond between paint and filler is perhaps a secondary characteristic. The paint job is over ten years old and as I said, it’s only started to do this over the last 2-3 years. Previously, any hard knock on a rock or such would scratch the paint or fracture it in little chips. Now an impact will leave a hand-sized flap of paint ready to be lifted off. The filler under the paint seems the same as ever, solid and pale gray in color.

 

[robert]

It kind of sounds like UV damage might be at the root of this. Throughout high school and university I worked for a company restoring heritage buildings in South-central Ontario, we would see this happen to oil based paints that had been exposed to a lot of sun. However, I doubt your canoe sees as much sun as a window frames and what not.
On the other hand, an older paint may have been ill equipped for the alterations in the atmosphere in the past decade.

Cheers;
Robert

 

[Larry Meyer]

Yeah, I doubt its sun exposure as canoe is stored right-side up in a garage. Very little sun exposure. But I would say the most conspicuous trait is the paint is less hard than it was and has an almost elastic or rubberized quality to it. This is all on the bottom of the hull, although I can’t rule out the sides as well, as I just haven’t cared to try to peel. Intelux used is of course an old-style traditional; oil-based enamel.

 

[Larry Meyer]

I did a google search and came up with an article discussing the longevity of acrylic vs. oil artist paints. As both are mostly used on canvas (by artists), the contexts are not that dissimilar. Haven’t studied the whole thing yet, but one point seems to be that oil paints are never entirely 100% chemically stable: so some fundamental change in the paint’s physical properties is not out of the question. It seems there are conditions in which the paint might become less hard, and acquire rubbery properties. Still the usual progression with artist and house oil paints is for them to become so brittle that they crack, rather than go rubbery.

Anyway, I’ve referred the question to my daughter, who is at Smith and working in the art conservation program there, to see if any of her associates have any experience with oil-based paints going rubbery.

 

[Todd Bradshaw]

Last time I phoned them the tech people at Interlux were fairly helpful and well informed. Might be worth a phone call. Maybe you can cover the hull with duct tape, pull it off and have a nice, stripped, filled canoe ready to repaint....

 

[Larry Meyer]

yeah that's a thought, or two thoughts, calling Interlux and just lifting all the paint up. I don't even think it would take duct tape! Actually, I'm more curious than annoyed right now. My usual repair technique with these flaps has been to pull the paint away until I reach an area that seems to have good bond remaining and repaint. But sometimes it seems like I could pull all the paint off in one piece! I suppose it beats sanding all the paint off. For now, I'll make do until the day I'm paddling along and the whole paint job slides off behind me.

 

[Larry Meyer]

Symptoms sound comparable, but conditions don't. What seems most striking is change in physical property of the paint going from hard enough to chip to rubbery. Never have left canoe in water for more than say 24 hours max. Maybe, if the Morris, was left out, rain an such also collected in interior? But that would mean water would have to seap through the filler to affect bond between filler and paint. Hmmmm.