DIY Copper antifoul

[Razorfish]

I am about to get my boat out for a spot of maintenance before the winter sets in. I coated the hull with Coppercoat 3 years ago and it has worked very well. Unfortunately there are some areas that need touching up from scraping the keel on the marina sill (we really wanted to get to the pub).

At £90 for a litre I wondered about making up my own version. A quick search on the web revealed that I can buy a litre of epoxy for £20-£25 and 500g of copper powder for under £10.

Has anyone tried making their own?

Is there any practical reason that this wouldn't work??

Thanks chaps!

 

[RichardTaylor]

Whilst I understand what you are trying to do, if it doesnt work then you will end up using a proven method next year.

The was a saying in the metal finishing industry "you havent got time to do the job once, but you have time to do it three times" in this case change time for time and money, as possibly in a years time you will be lifting the boat, preparing the surface again then painting with a proven copper-epoxy paint at the higher cost. Only you can decide.

 

[chewi]

I am about to get my boat out for a spot of maintenance before the winter sets in. I coated the hull with Coppercoat 3 years ago and it has worked very well. Unfortunately there are some areas that need touching up from scraping the keel on the marina sill (we really wanted to get to the pub).

At £90 for a litre I wondered about making up my own version. A quick search on the web revealed that I can buy a litre of epoxy for £20-£25 and 500g of copper powder for under £10.

Has anyone tried making their own?

Is there any practical reason that this wouldn't work??

Thanks chaps!

Reaing their brochures yesterday, they point out that others have had too coarse a grain of copper and other technical flaws that folded their businesses, and they place a lot of emphasis on following their instructions.

Their aqueous resin exposes the copper, not encapsulates it as your epoxy would.

They also do a smaller 0.5kg pack for repairs that treats 2 sq. m.

Your experiment would seem to have a high risk of failure & little to gain. You acknowledge the real thing works well, so spare yourself the cost and effort of scraping your failure off and replacing it. Spend the time in the pub instead.

Alternatively go for a cheaper lookalike and see if it matches up, then tell us all about it.


No connection, not even a customer, Just doing a risk assessment for you.
good luck.

 

[grafozz]

copper coating

I have been doing this for many years , contact East Coast Fibreglass Supplies , they have the copper powder and mix with epoxy resin at a ratio of 1x kg :2x litres of resin .
Then roller it on , mine lasted well for 8 years , after which I just scratch etched the existing copper and washed it well then re- applied my own mix 4x coats .
I found that 1 x mix would do 1 hull side before it cured .
Make sure you continuosly mix up the solution while being applied , as the powder being heavy , sinks to the bottom of the mixing pot . I use ice cream cartons so the short roller fits inside .
Th great side effet in this is that you have just epoxied your hull so put a good barrier on to prevent osmosis !
The worst job is removing the old a/f but it is very worthwhile . another point is to be very careful as you get down to the original hull gelcoat , dont damage it .
then lightly abrade the gelcoat before applying the copper to key the surface .
I recommend you get a team together for the a/ f stripping work , its slow going .

 

[Elessar]

Is there any practical reason that this wouldn't work??

Ordinary epoxy will not erode so once the outer layer of copper is spent it will cease to work.
Major epoxy manufacturers have tried to do it and failed.
So there must be more to it than meets the eye.

 

[electrosys]

I'm beginning to suspect that some people on here may have a vested interest in dismissing the idea of DIY copper anti-fouling ...

---------------------------------------------------------
From the CopperCoat website:

Coppercoat is the combination of a specially developed two-pack epoxy resin and 99% pure copper. Each litre of Coppercoat contains 2kg of ultra fine copper powder, the maximum allowed by law. [?]
On immersion, sea water attacks the exposed pure copper powder, causing the formation of cuprous oxide. This highly effective anti-fouling agent deters growth until the surface degrades further to become cupric hydrochloride. This final copper form is highly unstable, and is washed away [the copper oxide - not the epoxy resin] by the movement of the yacht, thereby removing any accumulating silt or slime. This automatically reveals a fresh copper-rich surface whereby the process recommences.

With the resin carrier insulating each copper sphere, the final coating is inert and non-conductive. A current can not pass through Coppercoat [...]

The inherent waterproofing qualities of the epoxy ensure that a treatment of Coppercoat will help prevent osmosis [...]

[...] after several years, the surface may benefit from being lightly abraded with a fine grade of “wet and dry” paper or a burnishing pad to expose fresh copper.

Classified as non-leaching, this highly effective coating is considerably kinder to the environment than conventional self-eroding anti-fouls.
---------------------------------------------------------


So - you can't have it both ways - either the 'special' [? - you might want to check their MSDS data sheets ...] epoxy resin allows leaching or it doesn't. If it allows water to penetrate past the top layer, then it cannot be considered as 'inert and non-conductive'. Good marketing spiel, with just a touch of the Paul Daniels.

And as for 'the others' producing an inferior product - remember the words of Mandy Rice-Davies ?

 

[Tranona]

Whatever the ins and outs of the formulation, you cannot ignore the past history of this type of product where a number of firms have tried to market their product, with variable outcomes - mostly failures with the possible exception of Copper Coat which is still in business and seeming to expand. If it was easy to produce an effective product there would be more than one brand on the market - I know there is a new entrant but they are likely to find it hard going against the background.

 

[Razorfish]

Yes they would, wouldn't they?

Well I think that given I have a hull treated with coppercoat and only a few patched that require attention, I will test a DIY approach and see what happens.

I will report back with results!

Thanks for all the comments.

 

[Poignard]

Perhaps someone can explain to me how it is that epoxy is good at keeping water out of your gelcoat whilst allowing water to get at the copper.

 

[penfold]

Perhaps someone can explain to me how it is that epoxy is good at keeping water out of your gelcoat whilst allowing water to get at the copper.

It's one of life's little mysteries isn't it? I think the point is that on the macro scale the thick layer of copper/epoxy is impermeable but the outside is burnished to expose the copper to the water.

 

[Poignard]

It's one of life's little mysteries isn't it?
I think the point is that on the macro scale the thick layer of copper/epoxy is impermeable but the outside is burnished to expose the copper to the water.

Seems reasonable - thanks.

 

[Razorfish]

Communication from Coopercoat

An update for those who are interested, I thought forumites would be interested in the technical information contained within....

A message from Coppercoat through the forum message facility:

"I am pleased to hear that your Coppercoat is working well. You may not be aware that we supply a half-litre kit (sufficient for just under 2 m2) and this is what most people buy for touch-up and repair purposes. This kit usually costs £xxxx plus £x.xx for delivery, plus Vat, giving a final total of £xx - but I could do this for you for a level £xx.

The advantage to this route is that you know that it works. And is legal and safe. It is actually illegal to make and use your own home-made marine pollutant pesticide, as such products need to be authorized by the HSE - not that anyone would know that you had done it (unless of course you go telling people on the Internet - Oooops!).

On a technical point, 500 gms of copper is not nearly enough for a litre of epoxy - we add 2000 gms of high purity spherical copper to each 1 litre of water-miscible low-solids epoxy. Use the wrong resin or the wrong copper or the wrong ratios and it simply doesn't work - as the would-be manufactureres of copy-cat Coppercoat have found out to their cost.

Its just a thought, and I wanted to make sure that you realised that you could have the real thing for your repair for far less than £90."

To be fair, ignoring the cost, Coppercoat does work well. But this forum being the haunt of true PBOers its still tempting to have a go isn't it?

 

[chewi]

I'm beginning to suspect that some people on here may have a vested interest in dismissing the idea of DIY copper anti-fouling ...

I have no "vested interest" at all.


My point was that the experiment wasn't worth the few quid he might save, nor the effort he'd have to expend to undo his experiment if it failed, and it had an odds on chance of doing just that.

Experiment by all means for experiment sake, we learn that way, but I think the OP might regret it financially and in use of his time.

Admittedly Coppercoat exploit that well, but they might be right, and that might be why they are still in business.

Its the OPs decision, his time, his money, his risk, so I wish him well whatever he chooses.

 

[Twister_Ken]

I have no "vested interest" at all.


My point was that the experiment wasn't worth the few quid he might save, nor the effort he'd have to expend to undo his experiment if it failed, and it had an odds on chance of doing just that.

Experiment by all means for experiment sake, we learn that way, but I think the OP might regret it financially and in use of his time.

Admittedly Coppercoat exploit that well, but they might be right, and that might be why they are still in business.

Its the OPs decision, his time, his money, his risk, so I wish him well whatever he chooses.

In true PBO fashion, maybe the OP should find a piece of GRP, slap some DIY copper on it, and hang it over the side for 6 months, before deciding which way to go!

 

[chewi]

In true PBO fashion, maybe the OP should find a piece of GRP, slap some DIY copper on it, and hang it over the side for 6 months, before deciding which way to go!

and he can tell us the results....top idea!

 

[Monique]

Razorfish,

Thank you for the lateral thinking....

I asked a metallurgist friend of mine for his expertise. I will post his thoughts when I get them.

He sails with me and knows all about barnies.... maybe we are onto something here!!!

 

[nimbusgb]

and he can tell us the results....top idea!

I have a test panel on which I did exactly that. It's been dangling off the end of a Brighton Marina pontoon for about 8 months now. Coppercoat ( genuine ) one side, home made the other. Very similar results. Must try to get an updated photo this week.

The old thread about this is here http://www.ybw.com/forums/showthread.php?t=263637&highlight=copper.

 

[Razorfish]

I have a test panel on which I did exactly that. It's been dangling off the end of a Brighton Marina pontoon for about 8 months now. Coppercoat ( genuine ) one side, home made the other. Very similar results. Must try to get an updated photo this week.

The old thread about this is here http://www.ybw.com/forums/showthread.php?t=263637&highlight=copper.

Pah, and I thought that I'd come up with the idea myself - nothing new under the sun! Good info in your post thanks.

I lifted the boat out today and the real coppercoat looks good with just a layer of slime that jet washed off very quickly. I am impressed by its tenacity (coppercoat not slime) as I got stuck on a marina sill last year and even after all that rubbing and grinding the coppercoat is still there - not as bad as I feared.

Hopefully I can apply my DIY version to a couple of areas tomorrow as the weather is looking good.

Cheers!

 

[pappaecho]

When I asked this question I was told that the epoxy is water soluble slightly, which is why it only last 10 years, nd why new copper becomes exposed with time.

Still waiting for mine to work, the bottom is covered in weed

 

[nimbusgb]

In the parallel thread to this one someone with ties to aquarius coatings states that the reason 'the others' failed in their attempts was because their epoxy was too impermeable to water.

I don't think the epoxy erodes so much as water gets in to it and the copper corrodes. When it does that the low strength epoxy allows the copper to become exposed.

So if the epoxy is, by inference, slightly permeable to water it can't be waterproof.