Antifoul starting to flake

[Skylark]

My hull is now 7 years old so it's had 7 coats of antifoul.

She was jet-washed by the yard when she came out in November. Around the water line, there's now a fair amount of flaking.

Last year, there was an area of about half a square metre under her belly, forward of the keel that had flaked. I tried to smooth it with a fairly course sandpaper. With hindsight, I wish I hadn't as I probably took as much off the gel coat. The antifoul does seem to have adhered well over this area.

The total flaked surface area is probably no more than 5% but it's starting to look unsightly and no doubt will continue to get worse until I do something about it.

What should I do? Is there an easy way to smooth out the flaking?

Many thanks for your advice / experience.

David

 

[Cotillion]

[ QUOTE ]
starting to look unsightly

[/ QUOTE ]

Only to the fish.

Just scrape off the flakey bits and go for no. 8

 

[flyingjunior]

You are probebly going to hate me for this but the best thing to do is to remove all the antifould and start fresh.
You should be able to get good glass friendly strippers (it tends to be easier on wooden boats lots of nitromose and a good tungsten tipped scraper) But it will take you a long time it took me a 2 weeks solid to scrap back a 34ft priors as antifoul after a while tends to almost weld its self to the other layers and the hull. Apart from seeing what has been going on underneth the antifoul and nip any probs in the bud you will have a faster yacht at the end.

 

[lw395]

You can get it blasted off, or scrape it with tungsten scrapers, old chisels, whatever works. Antifoul is quite variable, you may find a particular tool shifts it easily. If the gelcoat/epoxy is significantly scratched at the end of this, then consider a coat or two of gelshield or similar epoxy. When you have just a few small pits you can fill them but when it gets to a significant percentage in any area, it's time to take it off. You don't necessarily need to do the whole boat in one year, as the waterline always suffers first.

 

[Caer Urfa]

A surveyor told me once that he sees more hulls damage done with scrappers than thing else and I agree, just walk around your local boatyard.
Who cares what the hull looks like? it's underwater!
Are you realy interested in 'possibly' (very doubtfull) loosing point something of a knot?
My boat is 20 years old and has a resin coat ontop of the original GRP hull plus about 5 layers of antifoul & primer over the years build up and yes is not like a baby's bum, but presentable! After all you are suppossed to be protecting it not admiring it!.

I Jet wash down (to remove flake) light sand off, BUT i next coat with primocon primer which fills in a lot of the crevises then two coats of Micron Extra antifoul.
Lift out every two years with no problem up here on the East coast.
Mike

 

[BAtoo]

If its starting to flake that badly I would remove it, easiest to have it slurry blasted of but prob £500 or so to do it properly like that; or manually scrape it off - probably 5-6 days of hard work - you pays you money!!

Once off the prime (eg with primacom) two coats then antifoul. Also give the oppertunity to inspect and repair any minor damage/ touch up epoxy et.

As for speed poor antifouling has a marked effect. Similar thread here suggested a decent coat will slow a boat by 0.3kts or so and a crap coat of over half a knot (IIRR).

 

[johnalison]

I suggest you do what International say. Chip off all the loose paint with a scraper and then feather off the edges with a sander or block. Paint with primer (and sand again) before antifouling, with one of their wonderful products, of course.