Adding copper powder to antifouling

[Uncle Bob]

Originally Posted by CaptainRivet

The secret of coppercoat is simple.
The copper powder is mixed into water based resin used to seal concret floors in industrial buildings. It is not epoxy, it is water based epoxy that also doesn't create an absolute water tide barrier as expoxy primer/paint does. So if you don't put some layer of epoxy primer for hull protection before coppercoat application, you can even get osmosis underneath the coppercoat. i sadly know a sunbeam where it was applied to a new boat directly on the gelcoat and that sunbeam has osmosis now after 6 years.
Coppercoat tells you, you need that so coppercoat sticks to the hull. that is bs, it will do because the water based epoxy is made to stick over nearly everything except of oil contaminted surface...water and oil is not a good combo..(its to seal industrial concret floors, what do you think is all on commercial concrete floor before they seal it, definitly not just dust....thats why the application manual states no aceton, as this is oil based)
Because the resin is water based it disolves in water very very slowly and expose another fine layer of copper, approx 1/2 layer thick per year. Its basically the function of a self polishing soft antifouling but at a much much slower, finer and longlasting rate.
The magic is finding the right ratio between copper and resin, so a very thin microlayer of resin disolves over the right amount of time the coper is active. If it takes too long for the resin to disolver the coper layer is worn out and barnicales start to grow before the next "fresh active" copper layer can be exposed and makes the whole antifouling inoperativ. If too much copper is in the mixture the resin cannot encapsulate enough copper so in the beginning its very strong but too much copper gets worn in the first layer that next layer cannot operate properly as too much resin disolved at once and barnicales start to grow. Too less copper and its not enough "poison" that growth is prevented. Then how many layers can you apply, what thickness is minimum and what maximum. Add then regulation....
I know exactly what is in the original coppercoat, which exact resin is used and why max. 7 coats should be applied.
The reason coppercoat need to be activated is not because the copper oxidises out of the water (it does the same in water, its H20 so there is O=oxigin), the reason is that the waterbased expoy builds up a very thin but very hard top layer outside of the water that prevents the waterbased expoxy from disolving further. So you basically not reactivating the copper, you sand away the top layer from the waterbased epoxy that doesn't let it disolve further and at the same time sand a bit away oxide of the top layer (but the oxide is actually that what is the poison, not the copper itself).

ANd if you have to reactivate the coppercoat even your boat is the whole time in water means you are in too hot water and/or didn't mix this layer of coppercoat well enough and there is too much resin and too less copper in that layer...application failure.
The reason coppercoat works better in cold then warm water is also mostly the waterbased resin which easier disolves at lower temps then at higher temps and copper reacts faster as cold water contains more oxigen then warm water.

A little tip, if your boat is in hot water environment, put 100-200g more copper powder per 1l resin/1l activator then coppercoat supplies. They cannot do that because 2kg is the max allowed per regulation in a lot of countries but in warm water (25 degrees) the 200g per 2kg more emits the same amount then 2kg in cold water (18 degrees) as the resin disolves slower and therefor emits less copper.


So in higher temp environment it helps when you from time to time go over the hull in water with a black scotchbride to take away a microlayer of resin to expose more copper.
If you have coppercoat resin falling off on some spots you most likely didn't clean it properly or eg with aceton as the water based expoxy won't stick on an oil contamineted base as aceton contains oil. you must use high concentrated indutrial alcohol.

And here was me thinking that water was H2O, not realising that reduced temperature increased the oxygen level of water. Silly me.

[thinwater]

Originally Posted by Uncle Bob

And here was me thinking that water was H2O, not realising that reduced temperature increased the oxygen level of water. Silly me.

I can't tell if you are joking.

[Uncle Bob]

Originally Posted by thinwater

I can't tell if you are joking.

A riveting tongue in cheek reply to our good captains assertions re his "facts" about the oxygen content of water at different temperatures.

[RaymondR]

Originally Posted by s/v Jedi

7 months?! Do you realize that we went 5 years with antifouling before they banned everything that worked and only needed to brush off now and then after the first 3 years?

Yep, my first sail boat had Hempels TBT as it's first antifoul and when we lifted it three months short of five years the water blast bloke stalked off in disgust muttering "F?????g TBT" as there wasn't a job in it for him.

[goboatingnow]

Tbt is banned for good reasons. I personally think all underwater biocides should be banned on leisure vessels

[Wotname]

Originally Posted by fstbttms

Umm...

Why the 'funny' look?

Plenty of water based epoxy coatings used in a wide range of industrial applications.

[I14]

That wasn't his point. Although the post being referred to no doubt reflected valid observations to the writer, the chemistry and conclusions were wrong in various spots. Having formulated a number of WB epoxy coatings, they are to all intents and purposes no less water resistant than their water free cousins. They were originally used a lot for the coating of concrete walls inside buildings often below the ground level to hold back the hydrostatic head of water, combined with a reinforcement of the relatively weak outer layer of the concrete, coming through the concrete which they did well. It may be possible to formulate in some water sensitivity in the case of a binder for a copper containing coating by incoporating some water solubles in the matrix, like rosin for example, but the base polymer consists of a standard epoxy with a surfactant modified amine cross-linker to enhance water miscibility. The surfactants migrate out of the film and what's left, if formulated at proper reactivity ratios (termed stoichiometry), is as water resistant as any other epoxy. I don't wish to belittle other observations within the post as I'm sure they are earnestly felt.

[Pete7]

Originally Posted by goboatingnow

Tbt is banned for good reasons. I personally think all underwater biocides should be banned on leisure vessels

And replaced with what?

[Rustic Charm]

Originally Posted by ItDepends

You just do NOT know what you are talking about. TBT paint is legal in the eastern Caribbean.

And I don't care if you use it or not. So what you KNOW is true is NOT.

Also legal in Australia and New Zealand

[Rustic Charm]

Originally Posted by s/v Jedi

TBT? I guess over 25 meter boats isn’t many of sailboats for cruisers….

Tbt is a ‘restricted’ product in Australia and New Zealand. Prohibited on recreational vessels under 25m in australia. The government of the day not willing to save the environment at the expense of shipping.

No, not many of our sail boat fraternity would this affect. But I was just addressing those who keep saying it’s a prohibited product when it’s still being used.

[goboatingnow]

Originally Posted by Pete7

And replaced with what?

Non biocides

[goboatingnow]

Originally Posted by goboatingnow

Non biocides

Cause poisoning the water to go sailing isnt sustainable .

[fstbttms]

Originally Posted by Wotname

Why the 'funny' look?

Plenty of water based epoxy coatings used in a wide range of industrial applications.

That's not what I inferred but maybe you understood "It's not epoxy but it's epoxy" better than I did

[fstbttms]

Originally Posted by goboatingnow

I personally think all underwater biocides should be banned on leisure vessels

Well, that's a noble position to take but until an effective and affordable non-toxic anti fouling solution is found, it is of course, an unrealistic one.

[s/v Jedi]

A thread ruled by ignorance and the art of twisting the obvious until it appears like the opposite. There must be politician wannabees here.

Yes, water based epoxies exist. Yes, antifouling actually improves our environment by reducing pollution caused by fouling by half. No, there is no secret magic involved in making antifouling paint. Yes, TBT was banned in 2008. No, not all countries comply (fully).

It seems in situations like these it’s best to completely ignore posts that are based on nothing more than personal opinion. If you want to add weight to your posts, add citations, not shouting it louder.