pox

Here's another question. Old Cal 20 #1220 is developing the pox along the waterline and about 4" up. It seems to get a bit worse each year. It started under my ownership about 8 years ago (that long already???). These are not "blisters" but are more like "pimples," little bumps of about 1/8" diameter. It's every teen's nightmare, but my boat turns 40 next year. I'm assuming this is the usual osmotic blistering phenomenon, in a less drastic form. The questions that come to mind are: (1) can I arrest this by removing bottom paint and applying a barrier coating? And (2) does my bottom paint accelerate this? It was not present when I bought the boat, and she was already old as boats go. I changed bottom paints when I bought her and wonder if there's some effect of the copper in this formulation that would exacerbate the problem. The boat is not only in fresh water, which apparently is worse for blistering, but in pristine fresh water. Chris Campbell

I had the same problem on my 74 C25. Make sure its not blistering from the inside out. Just to be sure I would drain and paint the bildge with interlux bildgecoat. Next I would sand/sodablast the bottom to remove all the paint, open all the blisters and flush with freshwater to remove the glycol residue that resides in the blisters. let the hull dry out for a couple weeks and when dry, fill the blisters with west system epoxy thickened with 410 microlite. Cover the bottom with 4-6 coats of interlux interprotect 2000, then you will be ready for bottom paint again.It sounds like a long and hard process and Id be lieing if I said It wasnt. If you follow this process, the boat will outlast you. Ben Koche _____ From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Chris Campbell Sent: Monday, October 02, 2006 3:53 PM To: cal; Ca… [at] yahoogroups.com Subject: [Cal_Boats] pox Here's another question. Old Cal 20 #1220 is developing the pox along the waterline and about 4" up. It seems to get a bit worse each year. It started under my ownership about 8 years ago (that long already???). These are not "blisters" but are more like "pimples," little bumps of about 1/8" diameter. It's every teen's nightmare, but my boat turns 40 next year. I'm assuming this is the usual osmotic blistering phenomenon, in a less drastic form. The questions that come to mind are: (1) can I arrest this by removing bottom paint and applying a barrier coating? And (2) does my bottom paint accelerate this? It was not present when I bought the boat, and she was already old as boats go. I changed bottom paints when I bought her and wonder if there's some effect of the copper in this formulation that would exacerbate the problem. The boat is not only in fresh water, which apparently is worse for blistering, but in pristine fresh water. Chris Campbell