What is the best anti-fouling
I too asked the same question back in 2000 after anti fouling our large catamaran
every other year for 10 years.
After a review in Practical Boat Owner we successfully used Blake’s Tiger Cruiser as being cost effective in north European waters.
However after a retarded helper hired by the boatyard deeply penetrated gelcoat
we had to sandblast and do a full epoxy treatment with six coats of GelShield 200 after a winter’s dryout.
We decided to look into a 10-year coating and were attracted to Copperbot. Wessex Resins UK makes the product and at the time in 2003 had users with 16 years use without recoating. They were also agents for West Epoxy we used for fillers and bondings in preparation of hull.
Copperbot has now been renamed Coppercoat.
It comes as a two tin epoxy and a packet of ultrafine pure copper powder. The epoxy is quite unlike any other we have used. It is creamy in colour and one can even add a small amount of freshwater to dilute the mix. We rolled it on.
Coppercoat give detailed instructions on preparation, applying, mixing etc. Since they do not make West epoxy they would give no guarantee it would adhere to West epoxy. Equally they could think of no reason why it would not.
Having read accounts by other satisfied users we were prepared to take the risk. It could not be worse than having some incompetent damage the hull again or having my aged self and wife re-do it ourselves with traditional anti-fouling
It is a water-soluble epoxy which slowly dissolves leaving fresh copper powder exposed. For this reason it is important to stir the copper into suspension every time when putting it into the roller tray for application. It is also important not to mix too large a quantity at a time. We found it possible in weather
above 17 degrees C to apply two coats in a day The calculations given by Coppercoat for estimating the area for 5 coats gave us in practice 6 coats.
Also because the copper is in powder form there is no metallic conductivity possible. Therefore other metals such as prop, prop shaft, rudder
mounts or saildrive
legs are electrically isolated from Coppercoat. That is why it can be used on metal hulls.
We were so stressed before the launch we did not rub it down as advised. Now it has been five years on a drying mooring
in salt water
and cruised during the summers. There is absolutely no weed anywhere on the hull except for the un coated black painted stainless steel
propellers. They had green algae There was a hand print size patch of tiny barnacles
on the bottom of one rudder
skeg this year but that was easily removed one low neap tide. For five years use it is simply astounding. There is plenty of life around the boat. After cleaning
my wife and I collected a delicious meal of cockles and mussels around the boat.
We had a lot of interest in our boatyard since 2003. I noticed that almost every other boat when hauled out has put on Coppercoat since we did ours.
As far as my wife and I are concerned Coppercoat is a resounding success.
I agree with our colleague in Amstelveen. We know from personal experience it lasts for at least 5 years without visible sign of wear. I hope I last as well.