Antifoul removal

[iainfisher]

Hi,
I have just bought a 1974 23 ft Ruffian class and need to remove about ten layers of antifoul. Does anybody have any ideas on how best to do this?

Thanks

 

[imptish]

I did the same thing a couple of years ago and found the quickest method was to use a 3/4 inch wood chisel, overalls, face mask and a lot of patience. Keep the chisel sharp and the antifouling will come off quite easily.

Good luck, it's not a nice job!

Giles

 

[Gordonmc]

I used a chisel until a kindred soul introduced me to a hook-shave. Big plastic handle, disposable blades and a spout in the handle which fits onto a vacuum cleaner. More environmentally friendly than having chippings all over the yard. From chandlers or B&Q... the cash is well worth it.

The stripper goo is expensive and will fail to shift many layers of anti-fouling.

 

[quaelgeist2]

Dilunet - aggressive, but very effective stuff.
Leave on longer than recommended on bottle (8-12hrs rather than 1), possibly cover with clinge-film.
Remove with power washer.

Worked very well for me.

Don't forget to cover yourself, it's highly caustic giving unpleasant burns if getting onto your skin. Mind other boats in the neighbourhood when washing off.

have fun anyway
chris

 

[Guest]

Lucky you. It's a great job.

I always use a belt sander and just attack it.

I know, the dust isn't particulary good for you, but I think it's the quickest way.

A dust mask would help. A filtered mask even better.

Be aware you'll probably end up blue / green from all the dust.

Have fun
Jim

 

[sjohn_gibson]

I bought an electric scrapper (Bosch under £30) to do may 36 feet Macwester. It came with a selection of scrapper blades, one of which was ideal for the job.

The high speed vibrating effect caused the antifouling to chip off with ease and there was no damage done to the undersurface because the minimum of froce on the tool was required.

I subsequently used it to remove really stuborn tread mat glue using one of its sharp chisels - albeit care was needed as the corners of the chisel were inclined to dig into the gel coat.

I consider it to be one of the best tool buys I have made.

Good luck

 

[extravert]

Most of the replies here suggest doing it mechanically. I don't know which way is best as I've not done mechanical stripping, but I have done it chemically on a 10m hull using International Interstrip. It is a long slow expensive messy process doing it this way (8 days work and about £150) but the result was excellent. The boat looked and felt like it had just come out of a mold.

Interstrip doesn't make the old paint bubble like Nitormors on house paint does. Rather it just re-liquifies it. You then have to spoon off a nasty sticky layer of goo which gets everywhere. It gets through 3-4 coast at a go.

I tried Dilunet as well. This worked for soft eroding anitifouls but would not touch a layer of hard racing stuff.

I would suggest that if you are not interested in getting your bottom as smooth as a baby's bum then chemical stripping may not be the best way. Having done it I would think very hard about doing it again if I had a cruising boat.

 

[extravert]

Most of the replies here suggest doing it mechanically. I don't know which way is best as I've not done mechanical stripping, but I have done it chemically on a 10m hull using International Interstrip. It is a long slow expensive messy process doing it this way (8 days work and about £150) but the result was excellent. The boat looked and felt like it had just come out of a mold.

Interstrip doesn't make the old paint bubble like Nitormors on house paint does. Rather it just re-liquifies it. You then have to spoon off a nasty sticky layer of goo which gets everywhere. It gets through 3-4 coast at a go.

I tried Dilunet as well. This worked for soft eroding anitifouls but would not touch a layer of hard racing stuff.

I would suggest that if you are not interested in getting your bottom as smooth as a baby's bum then chemical stripping may not be the best way. Having done it I would think very hard about doing it again if I had a cruising boat.

 

[Twister_Ken]

Do the chips fly around, or is it a fairly 'clean' process?

 

[Johnjo]

Doing the same job myself today, On a Sabre 27.
Bought one of those two handed scrapers with a tungsten
blade, Cost 16 pounds money well spent,
Done half of one side in a couple of hours,
Has'nt being done for years so paint is really thick,
Will finish off with a belt sander, Leave it till spring,
When the hull should have dried out properly,If so will epoxy it,
Mate did his with that stripper stuff , Took him a couple of weeks.
And cost him a fortune, Where by I will still have the scraper
when I finish .
Mike

 

[AndrewB]

Did this a couple of months ago. I first bought a hook, which was impossibly slow. Sanding was hopeless, the soft antifoul quickly clogged the paper. I didn't want to use a chemical stripper as I wanted to preserve the epoxy undercoat.

Cracked it by spending a day going over the hull with a very high powered pressure hose at a range of about 1 inch, which blasted off most of the old antifouling but left the epoxy primer intact. The result was a pitted surface which it was then possible to sand with an orbital sander.

 

[petery]

Metabo do a paint plane that lets you skim off a very thin layer of paint/antifoul from 100 microns upwards. You adjust the depth to what you need It doesn't clog like a belt sander. I used it on a wooden hull to good effect - it even skimmed the bronze nails! It's expensive to buy but I believe you can hire them.

 

[quaelgeist2]

The caustic chemical stuff does not affect the epoxy layers. If the only concern reg. chemical removal is an epoxy layer, then do it!

More interesting is the fact that it apparently only works well on soft self-eroding AF. (when it worked so well for me, it actually went through 4-5 layers of soft stuff)

chris

 

[AndrewB]

Thanks Quaelgeist2, that's worth knowing, though hopefully it will be a long time before I have to do this again. In this case although I've only used eroding AF over the last 7 years, I found the bottom layers were the hard type - and very hard indeed given they have been there for 15 years.

Some of the lower layers were TBT, for which a proper face mask is an absolute must when sanding. I knew a guy permanently damage his lungs by sanding TBT, and it doesn't do the eyes much good either.