Copper Gelcoat

[properjob]

Does anybody remember that in the late 80’s and early 90’s it was suggested that mixing copper powder into the gelcoat when moulding a hull would have the same effect as one of the copper rich epoxy coatings which still seem to be popular.

The original owner of my Prout catamaran specified copper in the gelcoat when he placed his order in 1990. It seems as if he was not impressed with the results as when I bought her in 2007 she was coated with traditional eroding antifoul. This antifouling has now built up to such a level that it now needs stripping off. The copper rich gelcoat is still intact beneath the layers of various eroding antifoulings.

Does anybody have a craft with copper in its gelcoat and if so what is their opinion of it ? Does it work ? Does it need abrading annually ?

Whichever process of stripping off the antifouling is used it would roughen up the gel coat which might enable the original intention of putting copper into the gelcoat to work. It’s worth trying for a season, but does anybody have first hand knowledge of this method of antifouling a hull ?

 

[Elessar]

Does anybody remember that in the late 80’s and early 90’s it was suggested that mixing copper powder into the gelcoat when moulding a hull would have the same effect as one of the copper rich epoxy coatings which still seem to be popular.

The original owner of my Prout catamaran specified copper in the gelcoat when he placed his order in 1990. It seems as if he was not impressed with the results as when I bought her in 2007 she was coated with traditional eroding antifoul. This antifouling has now built up to such a level that it now needs stripping off. The copper rich gelcoat is still intact beneath the layers of various eroding antifoulings.

Does anybody have a craft with copper in its gelcoat and if so what is their opinion of it ? Does it work ? Does it need abrading annually ?

Whichever process of stripping off the antifouling is used it would roughen up the gel coat which might enable the original intention of putting copper into the gelcoat to work. It’s worth trying for a season, but does anybody have first hand knowledge of this method of antifouling a hull ?

It can't work for long, so is useless. Coppercoat erodes to release fresh copper. Once the outer layer of copper gelcoat has corroded, that's it it's spent. You could I suppose agressively sand to expose copper, but as this is the gelcoat there is something of a flaw in that plan........
It was tried as you say, there was a trade name for it which I forget. It was a flop.

 

[geoffatstanpit]

It was called Crystic Copperclad. It was an option on Parker yachts and my Parker 21 had it. It was 10 years old when I bought her and it worked quite well for a few years but eventually I had to put ordinary antifoul on in the middle where the barnacles live. At 17 years I had to do the whole lot up to the boot top. I tried abrading it to show new copper but that would have been much more work than cleaning off and putting another coat of AF.

 

[charles_reed]

Does anybody remember that in the late 80’s and early 90’s it was suggested that mixing copper powder into the gelcoat when moulding a hull would have the same effect as one of the copper rich epoxy coatings which still seem to be popular.

The original owner of my Prout catamaran specified copper in the gelcoat when he placed his order in 1990. It seems as if he was not impressed with the results as when I bought her in 2007 she was coated with traditional eroding antifoul. This antifouling has now built up to such a level that it now needs stripping off. The copper rich gelcoat is still intact beneath the layers of various eroding antifoulings.

Does anybody have a craft with copper in its gelcoat and if so what is their opinion of it ? Does it work ? Does it need abrading annually ?

Whichever process of stripping off the antifouling is used it would roughen up the gel coat which might enable the original intention of putting copper into the gelcoat to work. It’s worth trying for a season, but does anybody have first hand knowledge of this method of antifouling a hull ?

Yes I have it - ir was made by Scott Bader and called Crystic Copperclad. It seemed to do its job quite well, providing you rubbed down the whole surface about every 3 months - leave it longer the growth was such that a reasonably easy, if tedious job became a major challenge involving scrapers, wire-brushes and the like.
After 3 seasons I decided that, though more costly, it was far less labour intensive to use a self-eroding stannous antifoul.
I've since put 6 coats of Gelshield over the crystic copperclad, which was at its edges producing little blisters which were faux osmosis blisters.
I am assured that the modern epoxy-based copper systems are a totally different approach apparently having some self-eroding properties, but I haven't bothered to test that in practice.