Bottom Paint removal

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jdavis
Posts:10
Joined:Wed Aug 17, 2011 2:34 am
Bottom Paint removal

Post by jdavis » Thu Sep 08, 2011 4:03 am

My new to me SJ21 had several years of bottom paint which had to come off. The boat will only occasionally be in the water for 2-4 days, so I planned on hard painting the bottom with two part urethane if I was not able to save the gelcoat. This is the about the fourth boat I have removed bottom paint from, and the second to use a siphon feed sand blaster, no more grinding!. This blaster is not much of a tool really, about $20 from Northern Tools. But used with just enough air pressure(100-125PSI) to get the sand(cheap sifted and dried play sand) to siphone is just adequate to remove the paint just sneeking up on the gelcoat and moving on. The last few years of paint were red, over the original black, so when I exposed the black and the gelcoat was ghosting thru, then I moved on. The remaining black was easily sanded off with 150 grit on my VS random orbit sander on medium speed. I then went over the bottom again with 220 to polish off the sanding. I was able to salvage all the gelcoat with no areas going thru the gelcoat. The gelcoat had only minimally been scuff sanded for the bottom paint. In the pics you can see the black bottom residue after sandblasting, and then the adjacent 150 grit sanding.
Sanded with 220.jpg
Sanded with 220.jpg (8.59KiB)Viewed 10519 times
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After sandblasting and 150 sanding.jpg
After sandblasting and 150 sanding.jpg (7.12KiB)Viewed 10519 times

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TomD
Posts:78
Joined:Thu Jan 06, 2011 12:14 am

Re: Bottom Paint removal

Post by TomD » Thu Sep 08, 2011 6:26 pm

I am always amazed at the creativity and hard work that goes into fixing up boats. Great job and wow that looks good.

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cklamp
Posts:177
Joined:Fri Mar 25, 2011 3:34 pm

Re: Bottom Paint removal

Post by cklamp » Thu Sep 08, 2011 6:30 pm

Looks great... another option that worked really well for me is Peel Away. I removed about a Dime's thickness of bottom paint with this Stuff, and Andy Caples used it on Limpet as well, both in my driveway. Just "paint" it on, spread the "wax paper" over it, let it sit for 30 minutes or so in the sun, paint get's loosened up, pull the wax paper off, and most of the paint will come off with it.

The few parts of the paint still stuck to the Gelcoat can be pulled off with a 2nd application which I had to do in quite a few areas since the paint was soooooo thick, but Andy pretty much just had to do a little bit of scraping, then some sanding with 150-200.

http://www.fisheriessupply.com/productg ... nt+remover

Later
Christian
Fleet 1 Webmaster
http://www.sj21fleet1.org
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SJ21 1974 MKI #897, Mizu

jdavis
Posts:10
Joined:Wed Aug 17, 2011 2:34 am

Re: Bottom Paint removal

Post by jdavis » Thu Sep 08, 2011 10:17 pm

I didnt get any response from my cruising club's forum about using the strippers, I should have asked here. At almost $70/gal. how much stripper did it take?
Jim

jdavis
Posts:10
Joined:Wed Aug 17, 2011 2:34 am

Re: Bottom Paint removal

Post by jdavis » Thu Sep 08, 2011 10:22 pm

Thanks Tom, looking forward to seeing you on the water soon!
Jim
TomD wrote:I am always amazed at the creativity and hard work that goes into fixing up boats. Great job and wow that looks good.

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