Anti-fouling over Coppershield

[alan]

A friend of mine (here in Italy) has Coppershield on his boat; he has had it for about six seasons and has had it "rubbed back" every year. It is now getting to the point where it will need re-coating in the near future. He is considering getting it anti-fouled with standard "soft" ant-foul rather than coppercoat. He is getting conflicting advice from boatyards here as to whether he needs to remove all the old coppercoat (sand blasting?) and then start from scratch with a primer etc. Or whether the old coppercoat can be pressure washed and then primed and anti-fouled.

Anybody any practical experience of applying "standard" anti-foul to a boat that has been copper-coated???

Thanks in advance,
Alan.

 

[billgray]

We put 'soft' anti-foul on coppercoat - no primer - no sandblasting just a wash down. This was ten years ago and all is fine, just a pressure wash at end of each season and there is no great build-up of old anti-foul and no peeling patches so a win - win.
Bill

 

[Murv]

Did the same this Year with our new (to us) boat that had had a failed coppercoat application applied.
No-one could give a straight answer, the yard advised just slapping the conventional antifoul over the top and seeing how it goes.
No problems so far.

 

[Yngmar]

You probably mean Coppercoat, not Coppershield? If so, the stuff is basically epoxy (although water-based, once cured that doesn't seem to make much of a difference), just with copper dust stirred in. Therefore if you give it a quick sanding to key it, most things will stick just fine to it.

 

[pcatterall]

I would have THOUGHT prime and slap on the antifoul but the previous responses suggest no need for primer even.

 

[Daydream believer]

I just applied antifoul paint straight over copperbot with no primer & had no problem some years ago

 

[Deleted member 478]

You probably mean Coppercoat, not Coppershield? If so, the stuff is basically epoxy (although water-based, once cured that doesn't seem to make much of a difference), just with copper dust stirred in. Therefore if you give it a quick sanding to key it, most things will stick just fine to it.

What he says....

 

[pcatterall]

What he says....

+1 some coarse sand paper scratching to aid physical keying.

 

[alan]

Yeah, thanks guys; I actually meant coppercoat!!!
Thanks for the replies; I would agree that coppercoat is more or less epoxy, so I would suspect (as has been said) that just following the "rules" for ant-fouling over epoxy is the way to go.

Thanks for the replies,
Alan.

 

[vyv_cox]

My keel is Coppercoated, hull conventional A/F. Over the years I have not bothered to mask the top of the keel when applying hull a/f with the result that about an inch of paint has built up on the CC. This year I decided to clean it up. Removing the paint required sanding back, it was very well adhered to the CC. No primer used, I have never found the need for it.

 

[youen]

I put Micron International over coppercoat with no problems, no need of any primer