Copper Chloride in dinghy bottom paint?

[Jim Cate]

As a year round moored out live aboard, my hard dinghy may spend weeks at a time tied along side, but when I sail, I haul it up on the nets. I've been looking for a hard coating that would prevent growth but would not rub off on the nets. The nets are a great place for a nap on a sunny day, so I don't want them covered in toxic paint!
T

Perhaps this is a good match for the much reviled CopperCote (epoxy+Cu powder). MIght be worth a try.

Jim

[SV Bacchus]

I worry about the sealife that lives in the surf zone if he is going to be scraping toxic paint on beaches all over the Yucatan.

Is that a valid concern? I don't know enough about the longevity of the formulas he is discussing. Planning on using beach sand as sandpaper doesn't sound like a good idea.

[thinwater]

a. If you want to test stuff, paint fiberglass sheets in squares and hang them somewhere.


b. Who wants to bet the paint companies have tried have not every common copper compound? Please.


c. The solubility argument is... obvious.


But these things come up from time to time. Try it, side-by-side with a control, and post pictures.

[Bob Pullen]

Originally Posted by S/V Illusion

Copper oxide is water soluble as is copper chloride. It will work great.... for maybe 5 minutes.

beg to differ
encased in 2-part epoxy, several layers
think it over

[fstbttms]

Another issue regarding “renewing” the biocide by dragging the boat over sand is that not nearly all the painted surface will ever come into contact with the sand. Meaning these areas will never have any epoxy coating abraded to reveal fresh biocide. Not that the occasional dragging up the beach is going to do that anyway.

To those of you advocating adding tin or arsenic to the coating- Again, since there is no effective delivery method, it will likely be ineffective. But if by chance it were effective, intentionally introducing these highly toxic ingredients into the marine environment is a dick move.

[S/V Illusion]

Originally Posted by Bob Pullen

beg to differ
encased in 2-part epoxy, several layers
think it over

If it is "encased" or otherwise bound up in epoxy, it would be just as useless being unavailable as a biocide or an anti-fouling so either way, free or "encased", it would be ineffective at anything except decreasing your wallet size.

As you say think that over.

[fstbttms]

Originally Posted by S/V Illusion

If it is "encased" or otherwise bound up in epoxy, it would be just as useless being unavailable as a biocide or an anti-fouling...

Bwhahahaha! Of course it will be ineffective. But how could you be so rude as to point that out?

[thinwater]

Antifouling is subtle. Consistent release of something just toxic enough is darn tricky. It's not really a garage experiment. If only it were that simple...



The copper pipe in my left hand has a zinc anode. The copper pipe in my right hand is bare.




The pipe on the right has a zinc anode, the pipe on the left has an aluminum anode.

[Rough Magic]

Has anyone tried copper powder in acrylic water based paint? Ought to leach?

[AndyEss]

Tin based bottom paints, while no longer allowed in the US, are still used in other parts of the world and are for sale in the Caribbean (The Caribbean's Leading Chandlery - Budget Marine). Arsenic was a key component in wood treatment (CCA) that was phased out for residential construction in the US starting in 2003, but industrial and marine uses of CCA treated wood were extended. No requirement was made to remove existing CCA treated wood in the US. Other countries still allow CCA wood treatment. All the green treated wood you see is CCA (chrome copper arsenic).
I seriously doubt that a dinghy bottom experiment will "introduce" any new toxic chemicals anywhere as large scale industrial and even recreational use is ongoing.

[fstbttms]

Originally Posted by AndyEss

Tin based bottom paints, while no longer allowed in the US, are still used in other parts of the world and are for sale in the Caribbean...

The very great majority of seafaring nations (even China, for ***ks sake) have banned tributyl tin anti fouling paints, despite your attempt to rationalize their use. Only a few tiny Carribean countries still allow it because it brings in transient cruiser dollars, no doubt. It's use cannot be justified however.

Originally Posted by AndyEss

I seriously doubt that a dinghy bottom experiment will "introduce" any new toxic chemicals anywhere as large scale industrial and even recreational use is ongoing.

Pouring a bottle of motor oil overboard or flicking your cigarette butt out the car window isn't going to do any serious environmental damage either but that doesn't mean it isn't a crappy thing to do. Sailors should be part of the answer, not the problem.