Adding copper dust to bottom paint

[Steve Bean]

The statement, "Copper... doesn't corrode," is not true in all circumstances.

[thinwater]

Originally Posted by a64pilot

I used to think copper pipe in a house was permeant.
Until I had to replumb our house with Pex. The copper lasted about 30 years, was installed in mid 70’s and replaced early 2,000’s.
Our water came from limestone aquifer and as such was very basic, which I thought wouldn’t be as bad as acidic water, guess I was wrong.

This also depends on the grade of copper installed; heavy (S) or light(L). The heavy grade will typically last 100 years or more, but most installers use S because it is cheaper. Finally, there are more factors than pH.

[nwdiver]

Ahh.........copper was used in potable water systems to replace lead, this was before plastics were born.......lead was very bad and iron was hard to work and short lived....

[Westsailor32]

Originally Posted by lateral

You are better off putting cuprous oxide in .That is Cu2O not CuO.
It is reddy brown not black.

Anyone know what the amount of Cu2O to add per gallon that would help/increase effectiveness? At $30-40/lb that stuff ain't cheap.

[DIJ]

Originally Posted by hellosailor

Clive-
Coppercoat claims to have sold about 1000 applications per year after some 30-40 years of being on the market. That's a sneeze, not a market. We tried one of those products many years ago and after the stellar performance in the second year (not) became one of the many FORMER copper epoxy product users, who found it mainly fails.
If it usually worked--there'd be way more than 1000 applications per year by now. For whatever reason, it usually does not.

Have had Coppercoat on my boat for 14 years - only now are some small areas fouling - for 12 years the hull came out clean for its annual lift-out maintenance. It’s time now to redo.
At an initial cost of £950 (it’s a 36 footer) it has been extremely cost effective.

[hellosailor]

West-
"Anyone know what the amount of Cu2O to add per gallon that would help/increase effectiveness? At $30-40/lb that stuff ain't cheap."
The proper amount to add would be zero, if the [paint company has already done their job of properly formulating the paint. If you figure, very roughly, a gallon of bottom paint is $200 and contains 40% "solids", half of which might be the copper compounds? One gallon, four quarts, eight pints...so there's not quite two pints of copper compound in there. Maybe 2-4 pounds? Which is also why the stuff with high copper content has ludicrous prices.

DIJ-
I didn't say it can't, won't, or doesn't ever work. Just that the growth in their market share over the past forty years has been nothing, and a big reason for that has been the number of people who say that one way or another, it just didn't work for them. You are in a tiny minority, it has apparently worked for you. But if you raved about how well it worked, and told two other boaters why your bottom was so clean every year, and they each told two boaters every year....there'd be a hell of a lot more coppercoat on boats than there is now. After that many years, a superior product gets market share, just by word of mouth. Maybe it only works in certain waters, certain temperature, ph, species of crud, speed of currents. Those factors affect all bottom coatings. Even the folks at Interlux will tell you "Use this one in fresh water, that one in salt" and regionally, different brands are more or less effective. Coppercoat? Seems like no one has bothered to go around and take notes as to where it really may do some good, or not. Glad it has worked for you.

[Ringmaster]

Coppercoat gives you a bottom surface with the texture of concrete. If you want to go slow do your bottom with it. Also sanding it is just like sanding concrete.

[arcticmonkey]

bottom paint... hmm... knew an old university prof here in bc who was environmentalist before it was popular... he used as many coats of latex paint as he could get on before tide change.. sloughed off as well as bottom paint and a whole lot cheaper... made sense to me... I used it on my boat for years without a whole lot of trouble... you should be hauling out yearly anyway

[sailorboy1]

Originally Posted by hd002e

My boat is in an area where there are no regulations about bottom paint and there is a lot of barnacles growth. I was wondering if it would be helpful to purchase copper dust from a chemical supplier and mix that in with the bottom paint for anti-fouling. Would it be affective?

I’m not going read page 2&3 of the paint battle so excuse me if got back to point.

It wouldn’t be helpful. If it were the bottom paint people would it plus the higher copper bottom paints would win the practical sailor tests, but they don’t

What’s more likely to happen is the expensive bottom paint you paid for and worked hard to apply is going to fall off.

[Blue Crab]

Originally Posted by arcticmonkey

bottom paint... hmm... knew an old university prof here in bc who was environmentalist before it was popular... he used as many coats of latex paint as he could get on before tide change.. sloughed off as well as bottom paint and a whole lot cheaper... made sense to me... I used it on my boat for years without a whole lot of trouble... you should be hauling out yearly anyway

That's a whale of a tale cappy.

[Bill_Giles]

We had our Bavaria 36 done with Coppercoat about 3 years ago and no growth. In the UK it is pretty popular and seems to last well say 10 or more years. The copper used is pure metallic metal powder and the holder is a self abrading epoxy. So that the copper is exposed corrodes away to expose the epoxy which in turn etc etc. You can DIY it.

[skipgundlach]

This isn't really a discussion of CopperCote but since it seems to be a hot diversion, I noted, when we considered what to do, that nearly all of the success stories were in very northern waters.

As noted many pages ago, we went with $85/gallon (in 5G buckets) Sherwin Williams paint, which was tested in Biscayne Bay, a fecund environment near MIA for those not knowing it...

So far we're over 5 years on the first 'job' (2 coats plus more on the waterline and leading edges), and starting to show the second 'job' (different color). If the second color behaves even similarly, we'll be close to the 10 years bandied about by CopperCote for a grand total in material of under $900.

My memory may be failing me, because I remember the $85, but I also think/thought I recalled the 5G buckets being 325 or so. But I showed the 900 based on 10G@85...

I kinda like that number, and note that despite the age, our bottom cleans easily when at rest, and when moved a lot (such as our recent trip back from the Bahamas, about 130 miles in 3 days), STAYS clean. In between scrapes where we've sat in the awful-growth area of the ICW next to Vero Beach (of which the residue comes off readily) all that's needed is a scrub with a brush - which I do by intentionally grounding it on a falling tide, and going over the side with lots of weight and a hookah on my compressor.

YMMV, of course, but the guy who turned me onto this stuff has similar experience despite his using the 'fast' formulation (presumed harder, it's for boats normally over 10 knots and rarely at rest; mine is the under 10 knots, and often at rest formulation).

I don't dispute the CC advocates. But I can tell you for sure that the SW product is amazing and very affordable.

[OceanSeaSpray]

The OP's problem was barnacles. Three and a half years ago, I homebrewed a twin transducer ultrasonic system. This solved the barnacle/hard growth problem on my aluminium hull, they can't live and develop on it any more.
When it comes to weed and other soft fouling, the antifouling still has its role to play by a long way, but this is easy to clean. The hard growth is what makes a mess and damages the surface, so while not magic, it has been quite successful.

[lateral]

Originally Posted by Bill_Giles

We had our Bavaria 36 done with Coppercoat about 3 years ago and no growth. In the UK it is pretty popular and seems to last well say 10 or more years. The copper used is pure metallic metal powder and the holder is a self abrading epoxy. So that the copper is exposed corrodes away to expose the epoxy which in turn etc etc. You can DIY it.

Sounds right. Ewen said somewhere that the wb epoxy was 45% water. No wonder it slowly ablates. I find that figure hard to get my head around.
I used 100% solids with no blow off solvent so my Current Cu content was down by at least a third. Ever tried thinning paint 45%?
I doubt you would achieve 3kg /l and it be appliable. I should have used 3 and hit it with 15%solvent. Full ppe equip required then.
I'm going back to m66 until they perfect foul release. As fb said don't hold your breath.

[DIJ]

Originally Posted by hellosailor

West-
"Anyone know what the amount of Cu2O to add per gallon that would help/increase effectiveness? At $30-40/lb that stuff ain't cheap."
The proper amount to add would be zero, if the [paint company has already done their job of properly formulating the paint. If you figure, very roughly, a gallon of bottom paint is $200 and contains 40% "solids", half of which might be the copper compounds? One gallon, four quarts, eight pints...so there's not quite two pints of copper compound in there. Maybe 2-4 pounds? Which is also why the stuff with high copper content has ludicrous prices.

DIJ-
I didn't say it can't, won't, or doesn't ever work. Just that the growth in their market share over the past forty years has been nothing, and a big reason for that has been the number of people who say that one way or another, it just didn't work for them. You are in a tiny minority, it has apparently worked for you. But if you raved about how well it worked, and told two other boaters why your bottom was so clean every year, and they each told two boaters every year....there'd be a hell of a lot more coppercoat on boats than there is now. After that many years, a superior product gets market share, just by word of mouth. Maybe it only works in certain waters, certain temperature, ph, species of crud, speed of currents. Those factors affect all bottom coatings. Even the folks at Interlux will tell you "Use this one in fresh water, that one in salt" and regionally, different brands are more or less effective. Coppercoat? Seems like no one has bothered to go around and take notes as to where it really may do some good, or not. Glad it has worked for you.

I didn’t suggest you made any absolutes regarding performance but perhaps you might consider the higher initial cost contributes to the take up rate - also those locally I know who have been less impressed are those who haven’t lightly abraded it once a year - those who do that seem to be happier with it. I accept that local issues may be relevant to its performance .