copper coat antifouling

[bck73]

Hi There

I'm planning this season of copper coating the hull Im assuming plenty on the forum here have done this. I see in a lot of photos that people do the hull but not the keel. Is this normal! I know my B34 has a cast keel and does rust when out of water so I assume if I want to do the keel it would be a case of shot blasting back to bare metal and take it from there or do I just leave the keel and do the hull only has anybody any advice!

Mike
S/V Artemis

[FSMike]

I haven't used copper coat but I'm curious - where's Buckie?

[bck73]

North east coast of Scotland about 60miles of aberdeen

[osirissail]

Copper clad or cooper coating is a tricky and intensive process if you want it to work. I have seen "professionals" screw up the application and seen private owners who take the time and effort to do it correctly, have many years of successful service. So it is not an easy - paint it on - type process like bottom paint. You need to study carefully how to apply and burnish the copper prior to putting the boat back into the water.

[Wotname]

Originally Posted by bck73

Hi There

I'm planning this season of copper coating the hull Im assuming plenty on the forum here have done this. I see in a lot of photos that people do the hull but not the keel. Is this normal! I know my B34 has a cast keel and does rust when out of water so I assume if I want to do the keel it would be a case of shot blasting back to bare metal and take it from there or do I just leave the keel and do the hull only has anybody any advice!

Mike
S/V Artemis

Yes, do the keel. I suggest preparing the keel back to bare metal by method of choice, then coating with a high build epoxy primer (say Interprotect) and then the copper coat. CC sticks to Interprotect very well.

And yes, CC needs to applied carefully but it is quite doable if you attend to the details

[bck73]

Hi There

I've spoken to copper coat direct. they tell me as long and the hull is scrapped back to the gel coat and then a light sanding with wet&dry paper wached with fresh water and the temp over 20° it will be ok see attached
Application of Coppercoat

I'm just asking about the keel as I see plenty photo's with yachts leaving the keel undone.

rgds
mike

[Greggegner]

I had a Copper Epoxy bottom when we moved to Charleston SC from the Great Lakes. Had to add bottom paint to cut the growth down. It was a good barrier coat but would not keep growth off.

[bck73]

Hi thats Interesting all the forum I've read here in the UK swear by it. I see one yacht owner has had it on 17 years without a problem. Can I ask do you buff it with a scotch pad every year!

[Greggegner]

Different boat now, back on the Great Lakes. On the river in Charleston it was just not doing the job, maybe that would have helped

[bck73]

I know 1 person who has it and each season he dons the wet suit jumps into the north sea and scrubs the hull with scotch pad (green pad) whilst at anchor. he says it's only a light green slim thats on the hull each season so thats good..

[Greggegner]

Very warm in Charleston...a line left in the water for two days had more growth than you could imagine. We are talking HOT.

[FSMike]

From everything I've read it seems to work much better in cold water as opposed to warmer climes.
Thanks for the Buckie location.

[bck73]

Ok guys sorry I just assumed it worked in all climate's my mistake and yep north sea is cold..

[HappyGuy]

I own a Sparkman and Stevens 24 that I imported from NZ when I came back to South East Queensland to live.
I have recently completed a major restoration of this vessel and launched at the end of September 2013 about halfway between Brisbane and the Gold Coast
Years ago when I had the boat in Auckland I purchased a test pack of a copper/epoxy antifouling product that was being promoted at the Auckland Boat Show one year.
I did a patch about 100mm x 60mm on each side of the rudder with the product to test it out.
At the time I was using a commonly available copper-based hard antifouling paint on the rest of the hull.
I found that over a period of about 4 years the test panels worked as well as the normal antifoul at preventing barnacles. Yes I got slime on the whole underwater hull area and used to put the boat on a grid and scrub her off myself every 3 months or so.
Since a copper/epoxy antifoul is far more environmentaly friendly than normal antifoul I made the decision to go this way when I re-did the antifoul.
Since the product I had used was no longer on the market I did some research on the Internet to find a comparable product.
CopperCoat looked a likely product. There were testimonials that said the product worked very well and others that said it was a dismal failure.
I figured then that it was worth the gamble to give it a try since the earlier test panel had worked well on the rudder.
I stripped off the old antifoul with a biological paint stripper, sanded the hull and applied 2 coats of West System epoxy.
I sanded again and then applied 4 coats of Coppercoat in one day as per instructions.
Along the leading edge and bottom of the keel and on the rudder I glued shim copper as an experiment to see how it performed since the old sailing ships had copper sheet nailed to their bottoms for antifouling..
I hauled the boat after 4 ½ months of sitting idle on the mooring unused. A couple of small patches of the CopperCoat had got rubbed off on the trip to the marina to launch and I wanted to fix them as well as to see how things were performing.
There was a thin layer of slime on the bottom which came off very easily with the low-pressure waterblaster. Took all of about 5 minutes to wash the bottom clean.
There were no barnacles on the hull except where the CopperCoat had been rubbed off.
There was however a considerable growth of large barnacles on the propeller shaft, top of rudder shaft, bottom rudder shaft bearing and the rope cutter – all unprotected stainless steel.
One of the haulout guys said if it was his boat he wouldn’t have bothered to haul and blast with the amount of slime build up.
There was less slime than I used to get in 3 months in Auckland with conventional antifoul paint.
Average sea temp for February in Auckland is 21.2 deg C - and Brisbane’s average is 26.2 deg C.
I know 4 ½ months is not a very long test, but I am pretty pleased with performance so far, better than the conventional hard antifoul I was using in NZ.

[robwilk37]

i remember having this idea about 20 years ago. seemed pretty straight-forward... as much copper powder as you could suspend in epoxy and roll it on, burnish to expose the metal, simple. even did some test pieces on frp hung under the dock in san diego. a little slime after 2 years but thats it. no reason you cant mix it up yourself, copper powder is an easy get on line. id think a little cabosil to control the sag on the vertical surfaces would be needed.
in reading all the tech info on copper coats web site, i notice an assay report for total tin. does anyone know if this is residual or part of their "added biocide" ?