Stripping Bottom Paint

[SailinJay]

Just got the latest issue of Practical Sailor and in it they review several paint strippers. Very informative and it got me to thinking.

I am hauling out in two weeks and am expecting to find that I need to paint the bottom, as the old (Trinidad SR) has been on for three years, with the third year entirely in the water.

I sanded and painted the boat in 2004. It only had two coats of paint. I did all the work myself. The sanding was a bitch. This time around I figured I'd have that work done by a contractor, but still do the painting myself. Now I read this article about the strippers, and it appears that it's not that difficult and would obviously be cheaper than hiring someone.

Does anyone have any experience using strippers? Is it as easy at it seems to be (from the PS article)? My marina uses full tarps so the environmental issue of catching all the stripped paint is covered. They talk about getting the paint off with a scraper. Am I correct in assuming that it's your standard garden variety paint scraper?

Thanks in advance for any advice.

[Gene T]

Why sand or strip? Just scrub the bottom and ad another 2 coats and you're good for another 3 years. At least that's what I have done. The only reason to sand the bottom is if you have paint that is pealing or rough. But then I keep my boats in the water year round. I also use Trinidad SR.

[kneeman]

we did the bottom of our irwin 43 it had at least 12 coats of bottom paint west marine sells a stripper from interlux that worked great wear the gloves but dont do like the instructions say coat about 6 to 8 ft area do very bottom first. coat once wait about 15 mins and coat again wait 15mins or less you will see bubbles and start scraping 3" flex scraperworkswell.anything was better than looking like the smurfs also buy it in the gallon it does not go very far

[SailorMitch]

I partially agree with Gene T -- why remove the two coats of Trinidad assuming it is in sound shape? I'd repaint, but using an ablative so that you won't get a build up of layers of paint in the future.

But to answer your question if you really, really want to remove that paint: yes, I have used chemicals twice and they work very well. Depending on the brand you use, apply it, wait the stated time for it to work, test a patch to see if it comes off easily, if not wait a bit longer. I use plastic scrapers from Home Despot.

[Fstbttms]

Originally Posted by SailorMitch

I partially agree with Gene T -- why remove the two coats of Trinidad assuming it is in sound shape? I'd repaint, but using an ablative so that you won't get a build up of layers of paint in the future.

Before you commit to using an ablative over a modified epoxy, consider the following. You will not get superior anti fouling performance, you will be causing more harm to the environment and the paint will not stand up as well to in-water cleaning. Stay with Trinidad, IMHO.

[Gary M]

The strippers work pretty well. I just took 20 years worth off a 30 footer that I purchased less than a year ago. That much is very nasty. If you just have 2-3 coats the marine strippers will work well. You need rubber gloves and a cheap rain coat. A full mask is a good idea or use monogogles and be careful.

A wide stripper scrapper works well and also a pull scraper adds variety. I used an old large coffee can and after each scrape put it directly into the can. You will likely have to put a plastic sheet down to catch some of it.

Have Fun
Gary

[dustdevil38]

Hi-

I've used one of the Pratical Sailor test chemicals, Ready Strip. It did OK on the ablative topcoat, but was not near so effective on the underlying hard paint. Ready Strip softens the gellcoat a bit, so you need to let the surface dry out for a day or two after stripping and washing. Still had a lot of sanding to get it the rest off. I found this stuff at the local lumber yard for $28/gallon.

I agree with previous posts: unless you really need to get it all off, I'd sand the Trinidad and apply two coats of a good ablative.

sam

[SailorMitch]

Originally Posted by Fstbttms

Before you commit to using an ablative over a modified epoxy, consider the following. You will not get superior anti fouling performance, you will be causing more harm to the environment and the paint will not stand up as well to in-water cleaning. Stay with Trinidad, IMHO.

The process I outlined of applying an ablative over a base coat of Trinidad is what Pettit suggested I do when I stripped my bottom and applied an epoxy barrier coat two years ago. I followed their advice and am pleased with the results. Additionally, I have used Pettit Ultima SR (and its predecessors) for years here in the Chesapeake with very good results. Depending on the conditions where you keep your boat, you may very well find you don't need to do very much in-water cleaning with ablatives. That has been my experience. A bonus is that you won't get a build-up of hard paint over the years that will require a messy stripping job.

My $.02 -- or does that make it $.04 now?

[Fstbttms]

Originally Posted by SailorMitch

Depending on the conditions where you keep your boat, you may very well find you don't need to do very much in-water cleaning with ablatives. That has been my experience.

Good point. Boats that live a more brackish environment (as I suspect many in the Cheasapeake region do) may indeed do better with an ablative than boats that live in a marine environment. None-the-less, ablatives are more harmfull to the environment than epoxies, regardless of where they are used.

[Sailormon6]

Aside from environmental issues, the type of bottom paint you use should depend on how you use and maintain your boat.

Hard bottom paints last longer than ablatives, but, after you have applied them for a period of years, they build up a thick coat of old paint that eventually starts to crack and peel. When that happens, you need to consider stripping all the old paint off the bottom and start over again. If you do a good job of sanding it between each coat, and if you apply each coat properly, you might be able to go nearly 20 years before you strip it. If not, you might have to strip it much sooner.

Realistically, I think ablative paints are only good for one year. If you want a bottom paint that will last longer, you need a hard finish paint. Over the long term, ablative paints will save you a lot of labor maintaining the boat.

If you keep your boat on the hard during the off-season, then you can give your bottom a light sanding in the spring, apply a coat or two of ablative paint, and you'll be good for the season. If you keep the boat in the water for 2-3 seasons, then you have to use a hard finish paint.

Unless you're a serious racer, the bottom only needs to be stripped when it accumulates such a thick layer of old paint that it starts to crack and peel. If you have only put a couple of coats of paint on it since the last time you stripped it, it's unlikely that it needs to be stripped again, unless you got a bad batch of paint or didn't apply it properly, according to the manufacturer's instructions..