DIY Antifouling removal

[Pete7]

Having used two incompatible antifoul paints I was faced with the task of stripping the lot off plus previous coats. I bought a large bucket of International Interstrip as set to work. First problem the stuff has a consistency of wall paper paste dried to quickly in the May sunshine. Someone suggested covering with cling film which seemed too help keep the Interstrip damp and therefore working. In general it took a layer of paint off with each coat however, still needed lots of scraping. Despite using a large ground sheet for the sticky mess the tarmac garden path took a year to recover. It took 2 days to do a 24 boat sat on a trailer. This won't solve the keel problem, that would need wire brushes and an angle grinder.

Pete

 

[Lakesailor]

Two 1" chisels used in rotation plus an old fashioned grinding wheel.
Turn the chisel in use over and hold with forefinger under the blade and thumb over the blade. This, coupled with a fairly "square" edge to the chisel blade will rip off the AF in flakes quicker than you can say "bobs etc".
More time is spent sharpening the chisels than ripping, hence the need for two chisels. If one operator is fairly weak then he/she can be the dedicated sharpener.
I have removed about half a sguare metre in no more than 10 minutes using this method.

I've tried all sorts of methods and always come back to this. Just take the edge off the corners of the tip as well to prevent gouging.

Having used two incompatible antifoul paints I was faced with the task of stripping the lot off plus previous coats. I bought a large bucket of International Interstrip as set to work. First problem the stuff has a consistency of wall paper paint dried to quickly in the May sunshine. Someone suggested covering with cling film which seemed to help keep the Interstrip damp and therefore working. In general it took a layer of paint off with each coat however, still needed lots of scraping. Despite using a large ground sheet for the sticky mess the tarmac garden path took a year to recover. It took 2 days to do a 24 boat sat on a trailer. This won't solve the keel problem, that would need wire brushes and an angle grinder.

Pete

I tried the gloop method. What a pain in the arse. Took ages, wasn't very good and the mess was indescribable, not to mention the cost.

This was layers and layers of a mix of hard and eroding antifoul, in various colours.

This was years of erobable. It formed ripples along the forward part of the hull.

 

[JSYmartini]

I don't think theres anything wrong with good old fashioned sand blasting. With the proper equipment they can adjust the air pressure so it only takes off what you need to take off. It will pitt the gelcoat but it's very fine and perfect as a key for the base coat.

 

[JumbleDuck]

Have you thought about any of the Removall range? I've used their stuff for GRP boats and cars with great success. You slobber it on, leave it for 24 hours, come back and say to yourself "Damn stuff hasn't worked" because nothing seems to have changed. Then you give it a prod and realise that the paint is now a thick paste which you can practically remove with a spatula. It's non-toxic, biodegradable and completely harmless to GRP.

I may be coming across as a zealot here, but I am only a user, honest. I'd never go back to old-fashioned strippers, though, particularly on GRP.

Caveats (1) It's only good for about 3 coats per application, so if there is lots of antifouling or primer you may need two goes or even more (2) it has to stay moist while it's on, so do it on a damp day.