# Removing antifouling paint



## Badfish (Dec 17, 2000)

Ok, Im new to owning a Sailboat so forgive me if this is a stupid question or idea. My wife and I just bought an 11 year old 18ft trailer sailer. The previous owner didnt trailer it and only pulled it out of the water for winter so hes had the bottom painted with antifouling paint. We intend on trailering it so we really dont need the hull painted. The boat is in good shape but it is 11 years old so its got some small cosmetic problems that I would like to attend to this winter. One of them is the antifouling paint. Its thin in places and has turned ugly. My question is, instead of repainting the hull, can I remove the antifouling paint completely and restore the gelcoat? Is this so expensive or time consuming thats its impractical?


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## Jeff_H (Feb 26, 2000)

You can remove old bottom paint, but I am not sure that I would ever classify it as easy. Depending on the type of bottom paint you have two choices. If the bottom paint is of teh "soft" type or is a harder bottom paint like ''Vinylast''that has some age on it, then the fastest way to remove it is with a hook scraper. I have removed all of the bottom paint on a 22 footer in a little over a day. 
The key here is to get a hook scraper with a good handle and a smooth edge (rather than serated) and keep the blade sharp (carry a metal file in your back pocket and stop and sharpen when ever you feel like you are working too hard). Wear eye protection, a good quality repirator (face mask with filters not the surgical masks that are out there)and a tyvek suit.

I would do a test area first to see if the scraper will work. Hold the blade flat against the hull and be careful not to scrape into the gelcoat. I would then sand the bottom starting with a 220 grit to get off any residue. From there I would go with progressively finer wet and dry sandpapers until the hull is clean enough to use rubbing compound and wax. Do not use a silicone wax as they make repainting next to imposible. If you do nick the gelcoat deeply, then you are stuck sanding the bottom with a coarser paper and applying an epoxy or vinylester barrier coat. 

Plan ''B'' consists of using a chemical stripper. There are specially made chemical strippers that have a special paper that traps the chemical and holds it against the hull. While these are more expensove, smellier and less palatable to use, they are more environmentally friendly and do a very good job. You need to follow the directions explicitly and then use wet and dry sandpapers and compound like above.

Good luck
Jeff


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## Badfish (Dec 17, 2000)

Thanks Jeff, I kind of like the idea of a chemical stripper better than the scraper. The idea of me using a sharp blade to gouge away at my hull isnt very appealing. I can see me causing more damage than good. 
Im guessing its the "soft" type of paint. It has a chalky quality to it, If you rub a rag over it, it will actually chalk off on it. 
My next question is. When the hull was painted, the gelcoat was probably sanded in preparation so Ill have to restore that with fresh gelcoat, right? Or can I get by with just light sanding and buffing?
Another option that Ive thought of that may require less work but will solve the problem of ugly antifouling paint is to remove the antifouling paint thats on it now and replace it with shinier, slicker, more stable paint of a dark blue instead of trying to restore the original antique white color of the hull.
Thanks again, Ray


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## Jeff_H (Feb 26, 2000)

Used perperly with the blade perpendicular to the hull the scraper should not damage the gelcoat which is mmuch harder than the bottom paint that you are removing. That said the chemical stripper while a lttle more difficult still works quite well. 

Without seeing the boat it is hard to answer the question about the gelcoat condition. There are a number of ways that bottom paint can be applied. Traditionally,the bottom is preped by being washed with a solvent to remove any wax reside and then sanded with a moderately fine paper (180 or so). There are also "liquid sandpapers" which are a brush on surface prep. (Not my idea of a first class job) In that case the gelcoat might not have been sanded. Either way, adding new gelcoat is not a job for an amatuer. There are barrier coats that are made for coating bottoms and protecting them from blisters and the like but these are not visually attractive. 

I sort of like the idea of stripping the existing bottom paint and applying a hard bottom paint designed for in and out use. You should be able to get attractive colors and a slick enough finish to not hurt performance too badly. That way if you leave the boat in the water for a little while you won''y have fouling problems as well. 

Good luck 
Jeff


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## TSOJOURNER (Dec 16, 1999)

A purchased a boat from salt water and wanted to strip the bottom to the gelcoat.After trying sanding and scraping I went to the stripper mode. I had great success with a produce called Peel Away. It did not do any damage to the gelcoat and was easy to use but takes some time.I then sanded the bottom with 180 and then wet sanded with 250.I then painted with Interlux Epoxie and sanded that with 220 and wet sanded with 300 the bottom looks great and dose not pick up any slime over the summer.
Bill S


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## TSOJOURNER (Dec 16, 1999)

Just sand it down with a orbital sander and paint it a nice color with bottom paint. The whole thing should take 2 hours and it will look good.


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## Badfish (Dec 17, 2000)

Thanks for the replies everyone. I havent completely decided how Im going to approach this yet but its good to hear that it can be done and that I have options. Now I cant wait to get my other projects out of the garage so I can pull my P18 in and start it..... Ray


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## Jeff_H (Feb 26, 2000)

In as much as bottom paint is quite toxic, you would probably be better off doing it outside. Also it is not a good idea to let the residue soak into the ground. I would use a drop cloth to catch and contain the droppings. If you choose to grind or scrape it off where a high quality repirator. If you use chemical removers make sure to protect your skin. No matter which method you use, with all due respect to Mike, the job will take a lot longer than two hours. Then again the hardest part might be emptying your garage.

Good luck
Jeff


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## Badfish (Dec 17, 2000)

I ehaveb bEen inn My garAdge remOoveng anntifooulinng paintt Buut i FeEll fine.

J/K. , Thanks for the tip.


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## TSOJOURNER (Dec 16, 1999)

1. Find orbital sander and paper 20 minutes.
2. Sand 18 ft boat 30 minutes for a old guy.
3. Clean up and wipe the boat with thinner before the wife looks in the garage. 10- minutes.
4. Tape the water line 5 minutes.
5. Paint the bottom 20 minutes.
Total time 1 hour and 25 minutes.

I bet my 22 year old son could do it all in about an hour.

This spring I will go down to the boat yard with the orbital sander and sand the sailboat and wipe it with thinner. It should not take long. Maybe 90 minutes.

It takes 2 hours to tape and paint it. I use a very soft brush and paint in line with the water flow. This uses 1 gallon of bottom paint.

The boat is 27''+ on the waterline.

I do a nice job.


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## Badfish (Dec 17, 2000)

And, how do I get to your house and where should I park the boat, Mike ole pal?


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## TSOJOURNER (Dec 16, 1999)

A middle aged drywall guy can run up the stairs with 2 pails of compound in each arm. 

Thats 160 pounds of compound.

The tough part of the job is getting paid by you rich guys.


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## Badfish (Dec 17, 2000)

Ive done drywall. I hope refinishing my hull is easier than finishing drywall. If its not, I''ll just go ahead and plant shrubs around the boat because its not going anywhere for awhile. 
BTW, if your a good drywall finisher, your the one with the $$$.


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## parksider (Jul 25, 2009)

*sanding*

removing antifouling paintwith orbital sander just about 4 to 5 inch from waterline build up rest of bottom looks good how far can i bring it down too around water line


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## omaho5 (Jun 5, 2008)

Another tool to cosider using, IF you choose the scraping route, is a commercial painter's tool. It is referred to as a CARBIDE scraper, and is much 
more effcient than any regular steel scraper.
I'm a retred painting contractor and would not use any other tool.
Available at Sherwin Williams usually.
It wll remove the paint with MUCH less effort on your part.


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