Badly flaking antifoul

[strangford]

Just lifted out 2 year old 12 metre production yacht and the anitfoul is flaking off her really badly. The slings rubbed the antifoul off down to he white gel coat and most of the rest of the submerged surface of the hull is coming off with a light pressure wash. The hull was primed with Primocon before being coated with Cruiser Uno (by the dealer) a the start of the 2007 season when the boat was commissioned. April 2008 noted some flaking around slings etc re-primed then one coat of Cruiser Uno before re-launch. April 2009 the antifoul is falling off all over and you can see the grey Primocon on the back of the flakes. The hull is nearly back to the bare white gelcoat. Should this happen? Any advice as to what may have gone wrong is appreciated.

 

[Skyva_2]

Sounds to me as if the hull was not properly dewaxed or degreased before the Primocon was applied. Its a bit soon for this level of flaking.

 

[Pasarell]

Hull needs to be degreased to remove mould release agent then abraded before primer / antifoul applied. Some release agents are very hard now and take quite a bit of removing but often local applicators do a quick and superficial job.
If you bought the boat from new I suggest you go back to the agent and ask them to do it again.
It is important degreasing is done before abrading otherwise wax is forced into abrasion grooves and is much harder to remove.

 

[grafozz]

sounds like a great time to put copperbot/coat on to me , and give up the annual soluble paint scam ! just remove the rest , it may not take much , then key/ abrade the hull and put your own copper on . pm me if you want to know more .

 

[tomframe]

just sorting the same issue out right now, my boat is also just 3 years old - not a production boat though - we scrapped off the antifoul really easily in a section and the epoxy looked really shiny - what i think happened is they left the epoxy too long before the coat of antifoul, so it could not bond, and they almost certainly did not sand it, so I could only assume they messed up the timing.
I had all the antifoul blasted off (ARC) - only to find the original epoxy only had 2 coats, so we sanded it all down and this week we have done the 3 layers (grey, green , grey) just waiting for the weather to allow me the correct drying time so I can get the first layer of antifoul onto the epoxy in time for it to bond.
not the cheapest exercise, but the hull is so smooth now, in fact even smother that from the factory.

 

[samwise]

My local yard has reported some problems with adhesion of antifoul over Primocon, but nothing as serious as this. It certainly does sound as if the material has been applied over the remains of release agent. If the original commissioning outfit quibbles, you may need to get an independent survey of the problem ( or at least threaten to get one) which could get a result.

 

[Refueler]

If antifoul is old - when used it often onion-skins and comes away ... it can at times look like a dry river bed ...

This can happen with some 'bargain' antifoul via Jumbles etc. that is well past it's shelf life. I'm no paint expert - I just used to occasionally test paint coating thickness in dry-docks and preparation of ships hulls for it. But I believe it's because the carrier is old and lost its qulaity.