epoxy and copper powder on your propellor

[groundhog]

Anybody ever try this?
You could prime the bronze prop or maybe one coat of pure epoxy, then the copper loaded epoxy.

You can get copper powder on ebay pretty cheap.
groundhog

[sailingdog]

Don't put copper anti-fouling on a BRONZE prop. It will dezincify the prop and make it worthless...

[k1vsk]

It sounds from your plan to coat the prop first with epoxy that you are aware of the theory regarding mixed metals.

Making an emulsion of epoxy and copper powder, as you describe, will more than likely do noting except coat the prop with epoxy. The copper would be bound up in the epoxy making it effectively inert. You could put TBT in the epoxy with the same intent and it would similarly do no good.

One suggestion - Pettit Zinc Coat Barnacle Barrier paint

[sailingdog]

Actually, fine copper powder mixed into epoxy makes a fairly decent anti-fouling layer... provided you use enough copper powder per volume of epoxy.

Originally Posted by k1vsk

It sounds from your plan to coat the prop first with epoxy that you are aware of the theory regarding mixed metals.

Making an emulsion of epoxy and copper powder, as you describe, will more than likely do noting except coat the prop with epoxy. The copper would be bound up in the epoxy making it effectively inert. You could put TBT in the epoxy with the same intent and it would similarly do no good.

One suggestion - Pettit Zinc Coat Barnacle Barrier paint

[k1vsk]

Originally Posted by sailingdog

Actually, fine copper powder mixed into epoxy makes a fairly decent anti-fouling layer... provided you use enough copper powder per volume of epoxy.

I'd be interested in seeing any reference indicating this is true as standard epoxy is not soluble in or permeable to water making the hypothesis dubious at best. Same principle as typical barrier coat

[hellosailor]

At best, you'd be making your own "copperpoxy" type product, and there's a lot of debate over how well that works. AFAIK even the companies that make these products say they are not for use on props though--that should be a hint.

[groundhog]

Well, I work with a silver epoxy product that is so loaded with silver, that it is highly conductive.

It get's weaker as a glue though, as metal content is increased.

The thing would be to have enough CU in soulution to do the antifouling, but still be strong enough to stay on the prop when rotating.

[sailingdog]

I'd recommend you look at CopperCoat, which is a UK-based antifouling paint that is just that.... very fine powdered copper in an epoxy base.

Originally Posted by k1vsk

I'd be interested in seeing any reference indicating this is true as standard epoxy is not soluble in or permeable to water making the hypothesis dubious at best. Same principle as typical barrier coat

[Fstbttms]

Originally Posted by sailingdog

I'd recommend you look at CopperCoat, which is a UK-based antifouling paint that is just that.... very fine powdered copper in an epoxy base.

Somehow, I don't think that copper-loaded epoxies (CopperCoat, Copperpoxy etc.) are as easy to duplicate as simply dumping some powdered copper into a tub of West System.

And FWIW, in my neck of the woods, copper-loaded epoxies (which are not paints, BTW) don't work for sh*t.

[Maine Sail]

Originally Posted by k1vsk

I'd be interested in seeing any reference indicating this is true as standard epoxy is not soluble in or permeable to water making the hypothesis dubious at best. Same principle as typical barrier coat

Epoxy with enough of any filler is and can become permeable. This is why wood flour or Microballoons are not generally recommended fillers for below waterline applications.

I just had my bottom stripped faired and barrier coated. When we had it down to bare gelcoat I noticed microballoons around the strut used as a filler/fairing compound.

When I put my meter on it it read nearly 6 times the moisture content of the surrounding polyester gelcoat (and no this was not Bondo it was epoxy & microballoons). We went ahead and removed all the microballoon filling and fairing done by the PO and re-did it with an epoxy mix consisting of milled fiber and cabosil.

The filler can contrubute a lot to moisture absorbtion despite it being mixed in with epoxy..

As others have said it is not a wise idea to coat a prop with copper as many of them are made from manganese bronze. Manganse bronze, depending upon grade, can have as much as 40% zinc content..