Boat bottom

[scottmc]

I have an older boat and the aniflowing paint is coming off in large pieces. Has anyone remove it down to the gelcoat, if so how and what did you use? I was thinking ov sandblasting it with bakingsoda.

 

[oly5050user]

go to boat supply store and ask about chemical paint remover..messy job but effective..Did mine 3/4 years ago after a 12/15 year build up of bottom paint..Every yeart I used to scrape and do some sanding then apply new paint..Still do..no need to do complete removal every year..

 

[Jim C]

Check out thehulltruth.com lots of info on boats there.

 

[cnctina]

Baking soda is not agressive enough, if you use sand like flint cut the paint will blast off fast but you will open up every inperfection with the gelcoat and you will have 40 hours of filling and sanding. Without seeing the boat bottom I can only recommend 40-80 grit on a DA sander. If the paint is comming off in sheets it is because of a improperly prepared surface so you will have to strip the entire hull. If you are good you can rip paint off with 36 grit on a 7" disc sander.
Do not use chemical etchers to prep the surface, they don't work very well.

 

[ItsBruce]

Remember the stuff is very toxic. A dust mask may not be sufficient. There may be local laws about removing and disposing of bottom paint.

 

[wreckchick]

The guy I know that does bottom paint sands it all off before prepping it for the next application. He's a full paper suit and uses a respirator. It is nasty, nasty stuff.

Rachel

 

[scottmc]

I really don't want to be sanding this stuff. Thats fine for prepping for a new coat, has anyone tried washing it off with a pressure washer?

 

[Tom Winters]

You can try a pressure washer. Some commercial shipyards use high pressure water to strip metal hulls, but they do this in a containment facility that filters the paint crud out of the slurry. There are even magnetic crawlie jobs that march along the hull automatically blasting away. It sure beats the mess that conventional sandblasting causes.
When I had a small boatyard, I found the best tool for removing bottom paint was using illegal immigrants. They were relatively inexpensive, did fine work, and then moved on. Up there in Ontario, you must have all sorts of illegals floating around.
After you use the water pressure to knock off the chunks of paint, a company called Fein in Germany makes a line of sanders and vacuums that are so efficient you can sand a hull bottom in normal clothes and a respirator and not die soon after.
They're well-balanced and your arms won't vibrate off after an hour of grinding away. They make an 8" sander that is really awesome, but that might be a little overkill for you. And yes, they are EXPENSIVE, but you only buy it once in your lifetime.
It makes the truly onerous job of bottom sanding not-too-bad.

 

[captain]

When I had a small boatyard, I found the best tool for removing bottom paint was using illegal immigrants.

I have to agree with that. I have sanded bottom paint off of two boats I owned and that was two times too many.

 

[cobaltblue]

You may also want to try to call some local companies that do sandblasting. It is well worth the couple to few hundred dollars to have someone else take care of it for you. I've run three marinas and now have a couple of my own marine businesses and it's still cheaper and less hassle to have someone with an industrial sandblaster come in a spend an hour or two doing it. When you figure in all the materials you need, whether it be chemical strippers or sandpaper and such, your time and all the other costs, to me it's a no-brainer. Not to mention the fact that it's a nasty job to try and do yourself.

On another note, if you do have it sandblasted, barrier coat it before you paint it. It will protect you bottom and will increase resale because it only needs to be done once and after that, you only need to bottom paint.