Best way to remove bottom paint and barrier coat from rudder

[saurav16]

What is the best and cheapest way to remove barrier paint and bottom paint from rudder? If you suggest sending is it ok to use an orbital sander say with 80 grit sand paper? Sorry first time doing this, thanks in advance.

[BarryL]

How much paint and how hard is it? Why do you want to remove the barrier coat?

My boat had what appeared to be 20 years worth of paint build up. This was old, hard, caked on paint. I tried using paint stripper (Franmar Soystrip, them Interlux paint remover), then sanding, then scraping, then soda blasting.

The paint strippers didn't do much. The Franmar worked better than Interlux, but didn't work great. It softened the paint, but didn't remove even 1/2 of it. Sanding worked OK but was very slow. Scraping worked best.
Since I had a 35' boat to do, I gave up and paid the soda blaster guy.

For just a rudder I would scrape with the most expensive paint scraper you can buy. In my case is was a $20 unit with a carbide bit. I bought it from Home Depot. That should work well. Then sand with 80 grit and you should be OK.

GOOD LUCK!

Barry

[saurav16]

I am removing it to do repair work (glass and epoxy) on the rudder so the paint needs to go. Thanks for your response barry.

[RickQuann]

This may be a dumb question, but what exactly is soda blasting? I heard of sand blasting, which I think most people avoid anymore, but not sure about the soda. Thanks in advance

[saurav16]

its blasting with baking soda i believe.

[sailingdog]

I'd second using sodablasting... it is relatively inexpensive, and gets the job done properly and quickly. BTW, it is blasting using baking soda, but the granules are larger and coarser than the food grade stuff.

[KeelHaulin]

I'll suggest it again... Peel-Away (non-marine) can be purchased at a local Sherwin Williams for about $20/gallon. You apply it with a trowel and cover it with the provided paper-backed plastic. 24-38 hours on and it will remove 10+ coats of epoxy based bottom paint. Of course you will have to dispose of the paint flakes with stripper but it sure beats sanding.

It's a caustic lime based paste (probably Calcium Hydroxide) and it will remove most paint down to gelcoat. It will strip gelcoat if you wait too long; but that should not happen; all you need to do is check it every 6-12 hours.

The marine version claims that it will not harm gelcoat; but I used it on my transom and it blistered the gelcoat. So it makes no difference really if you use the marine or non-marine version on the bottom or rudder.

[RickQuann]

Ah, I see. I stripped my rudder a few years ago because of moisture within and I used a stripper and putty knife. The hardest part was removing it from the boat because of the weight (transom hung) Five barrier coats and three coats of Micron cured my moisture problem.

[Sailormon6]

Don't use any chemical paint stripper unless it is specifically formulated for use on fiberglass.

The paint stripper that I use works as well as any I've found, costs about $20-30 a gallon, and is available most anywhere, but not in discount stores. You often have to go to a paint specialty store and order it. I use Klean Strip paint remover. They make several different types, but you want the type that is specifically designed for stripping paint from fiberglass. The other stuff is too aggressive, and will literally dissolve your gelcoat.

I think I paid $20. or $30. per gallon for it last year. It only works well when the temperature is above about 60 degrees. I applied it with a 4-5" brush, waited 30-40 minutes and brushed on another coat, waited 30-40 minutes and brushed on another coat. The trick is to keep it wet, and let the chemicals do the work. Don't get overly anxious and try to scrape it before it has loosened the paint. It'll be easier if you're patient. After 3-4 coats, try scraping a small area with a putty knife or scraper to see if it's loosened enough. If not, brush on another coat. Also, don't leave it on overnight. If you leave it on that long, it'll just dry out, and it won't work any better. If I remember correctly, you want to use a natural bristle brush, because the stripper will eat the bristles of a man made brush.

Also, I use synthetic latex (not natural latex) surgical gloves. You can get them at many drug stores for about $10. for a box of about 100. They withstand the chemicals, and, if they get too slimy or get a hole in them, you can just peel one off, throw it away, and put on another one. Also, wear old long pants and a long sleeved shirt, and keep a roll of paper towels handy, because the stripper burns if you get it on your skin. Wear eye protection, to prevent the brush from flipping paint stripper into your eyes.

[KeelHaulin]

Well I used about 12 gallons of non-marine Peel-Away two years ago; it didn't dissolve the gelcoat (but the MARINE "GELCOAT SAFE" product made by the SAME COMPANY did damage some topsides gelcoat on the transom). I think it depends on the formula; the type that has methylene chloride as a solvent will definitely dissolve epoxy and gelcoat; the caustic lye in Peel-Away is slower acting and much less agressive.