Bottom Paint 1, Me 1

[BarryL]

Hello,

I'm making a little progress in my bottom paint strip process.

What I'm up against:

http://www.sailnet.com/photogallery/...7/Image033.jpg

How it looks after chemical stripping, manual scraping, and random orbital sanding:

http://www.sailnet.com/photogallery/...7/Image018.jpg

I think the real cause of the problem was that the bottom was barrier coated at one point, and then the bottom paint did not adhere to the barrier coat. This has caused large chunks of paint to flake off

http://www.sailnet.com/photogallery/...7/Image021.jpg

If you look at the second pic, you can see the difference between the white gelcoat and the gray barrier coat. If I am correct, does that mean I need to remove the barrier coat and start over?

I have lots of work ahead of me. Today I bought a new scraper with a carbide bit. That seams to work the best so far.

Barry

[Freesail99]

Barry I bought a 1.25 inch gasket scraper from sears for 10 bucks. Wonderful tool for bottom scrapping. Looks like a lot of paint that was never removed to me.

[Sailormon6]

Barry, the condition on your boat appears to be caused by the application of many, many coats of bottom paint through the years. The cracks in the bottom paint look much like the cracks in the bottom of a dried-up lakebed. When it gets that way, the only real remedy is to strip it off and start over. The more layers of paint you put on, the more it cracks and peels. I've stripped two boats now.

Ideally, all the old antifouling should come off. It would be nice if you could take off only the old antifouling, but leave the barrier coat. But, when I chemically stripped my first boat, the chemical stripper removed the barrier coat along with the antifouling. If you want to prep the boat for serious racing, you should strip everything, however much work it requires. If you want to prep it for cruising and club racing, I would suggest you keep sanding the antifouling until you can't stand the thought of doing it another day. By that time, you should have it smooth enough for cruising and club racing. Then I'd put a couple coats of good ablative antifouling on it and go sailing. Each year I'd put another coat or two on it, depending on whether it's hauled during the off season.

IMHO, wet sanding, by hand, with a medium grit sanding disk removes antifouling faster than using an electric sander.

[sailingfool]

Paint chips like that when it gets thick, a barrier coat need have nothing to do with it. With that much paint, I'd be surprised if there is a barrier coat under it - I don't think they were in use many years ago...That's the magice with ablative paint, it wont build up - just repaint as needed.

If you decide doing it by hand is too painful (as it is...) you might get a quote for blasting - maybe a local guy wil be doing some other boats and giver you a deal..

[sailingcal21]

I'd highly recommend getting a quote from someone who uses the Farrow System http://www.farrowsystem.com/. Just had my bottom done for $26/foot and was pleased with the results (of their work). I gotta do a good bit of tiny blister filling, it looks like by bottom has a case of the measles.

Seems that this system allows the user to control the cut very well. Something to do with the low pressure (40 psi) and the fact that the media is very fine. All my bottom paint was removed leaving the barrier coat intact.

[sailingdog]

I'd recommend SODABLASTING the bottom of your boat. I did this earlier this year to my boat... was worth every penny.

[BarryL]

Hello,

In case anyone still cares about this, I have completed my bottom stripping.

I tried chemicals, no good (I think it was too cold). I tried scrapers. The scrapers worked, but it was VERY slow going.

So I gave up and hired a soda blasting guy. For $1700 he did a great job.

Some pics are here:


I need to do a little sanding, clean up the keep, then barrier coat and paint

IMHO, the price was well worth it.

Barry

[Faster]

Originally Posted by BarryL

So I gave up and hired a soda blasting guy. For $1700 he did a great job.

$1700??? How long did it take? Where can I buy me one of those soda blasters?

[sailingdog]

Barry-

That sodablasting sounds a bit pricey... I had my boat done, yes all three hulls, last summer, and it was almost half of what you got nailed for.

Faster—

In case you were serious... you can get the equipment here.

[KeelHaulin]

If the surface appears rough; with highs and lows and generally porous, you should sand it smooth before putting down paint. The porous surface caused by "blasting" can cause further problems with blistering. Sand blasting is a definite no-no; don't know how soda blasting compares...