Adding copper powder to antifouling

[Bowdrie]

My next boat, (in my dreams,) will be 70/30 CuNi.
Yeah, some life forms will stick to it, but can be easily pressure washed or brushed off, and no more application of bottom paint.

https://www.copper.org/applications/...boat_hull.html

[RaymondR]

"One of my DIY schemes was to build a machine which I could feed surplus stranded electrical cable into to turn it into powder and then sprinkle it onto release agent coated 18" wide paper strips to get an even coating. One would then epoxy coat the hull and apply and roll the paper strips onto the wet epoxy and leave it to dry. After the epoxy hardened one would then hose the paper and release agent off leaving an even coating of copper on the hull. I had a multi chine steel boat then so the paper strips would have fit well onto the single curvature."

I forgot to add that one of the advantages I perceived with this scheme was that the resulting surface emulated the low drag skin of sharks and that I expected to get another knot out of the boat.

[s/v Jedi]

Originally Posted by RaymondR

"One of my DIY schemes was to build a machine which I could feed surplus stranded electrical cable into to turn it into powder and then sprinkle it onto release agent coated 18" wide paper strips to get an even coating. One would then epoxy coat the hull and apply and roll the paper strips onto the wet epoxy and leave it to dry. After the epoxy hardened one would then hose the paper and release agent off leaving an even coating of copper on the hull. I had a multi chine steel boat then so the paper strips would have fit well onto the single curvature."

I forgot to add that one of the advantages I perceived with this scheme was that the resulting surface emulated the low drag skin of sharks and that I expected to get another knot out of the boat.

I love the idea, but a possible failure to hose off the paper after cure makes for interesting visuals

[oceane]

Hi all,
does anyone have background & knowledge on using/adding super hydrophobic silica to an epoxy base, for example Cabot TS-720!???

i'm testing it on my epoxy dinghy bottom for a few months now, with boric acid , TS-720 and graphite powder, ...not perfect, shells/mussels won't stick but seaweed do grow if dinghy not moving for a few weeks, but easy to remove with light scrub!!!!...maybe copper would be a better biocide than boricacid, but haven't try combining copper and superhydrophobic silica yet!!!

all feedback on superhydrophobic silica welcomed....

[I14]

You won't see much or any advantage over using standard fumed silica like Cabosil M5. TS720 being hydrophobic enables you to get more into your mix before the viscosity goes too high so improving the surface hardness a little. Being 'super hydrophobic' doesn't help much, standard unmodified fumed sillica has been used as a viscosity control agent for resin systems below the waterline for all time pretty well. Have you had prior experience of using boric acid as a biocide? Being an acid it will react with the amine Part B of the epoxy mix but, since it seems you have got it to work, not significantly but the boric would be best stored in the Part A if you wanted to keep it for any time.

[s/v Jedi]

I’m entertaining crazy ideas like putting Biobor JF in a paint like Kilz Mold & Mildew water based primer. Maybe add cuprous oxide to it.

[I14]

Doesn't sound that crazy, from Wiki 'Concentrates of borate-based treatments can be used to prevent slime, mycelium, and algae growth, even in marine environments'. I think it would be more effective than boric acid straight as the form of the boron compound seems to be a factor with efficacy. Note Biobor JF is banned in EU?

[myketch42]

I was referencing the initial sanding to expose the copper grannules

[s/v Jedi]

Originally Posted by I14

Doesn't sound that crazy, from Wiki 'Concentrates of borate-based treatments can be used to prevent slime, mycelium, and algae growth, even in marine environments'. I think it would be more effective than boric acid straight as the form of the boron compound seems to be a factor with efficacy. Note Biobor JF is banned in EU?

I think the Biobor JF will do fine as the biocide… but the Kilz primer is a complete wildcard, based on a hunch that it might work after I used it to spray a room with it. I plan to do some test patches over the new coats of ABC3 that I luckily still have.

[thinwater]

Originally Posted by goboatingnow

Cause poisoning the water to go sailing isnt sustainable .

CA and WA EPA have studied this and disagree. They settled on a leaching rate. Done.

[thinwater]

Originally Posted by s/v Jedi

I think the Biobor JF will do fine as the biocide… but the Kilz primer is a complete wildcard, based on a hunch that it might work after I used it to spray a room with it. I plan to do some test patches over the new coats of ABC3 that I luckily still have.

No, it will not. It is not very toxic to marine invertebrates (check the SDS). The active ingredient is boron, which is already present in seawater in significant amounts, so they're kinda used to it. It is optimized for fungus and bacteria, and is not even full spectrum for microbes. It will also most likely leach out in a very short period.

[I14]

Originally Posted by s/v Jedi

I think the Biobor JF will do fine as the biocide… but the Kilz primer is a complete wildcard, based on a hunch that it might work after I used it to spray a room with it. I plan to do some test patches over the new coats of ABC3 that I luckily still have.

Might not last long underwater

[s/v Jedi]

Originally Posted by thinwater

No, it will not. It is not very toxic to marine invertebrates (check the SDS). The active ingredient is boron, which is already present in seawater in significant amounts, so they're kinda used to it. It is optimized for fungus and bacteria, and is not even full spectrum for microbes. It will also most likely leach out in a very short period.

I would add it for the soft growth, for which is should work good. The rate of leaching out is determined by the base paint, not by the biocide, why would you claim that?

Anyway, there will be some test patches of ABC3 with Biobor added. We’ll find out.

[s/v Jedi]

Originally Posted by I14

Might not last long underwater

That’s what I am afraid of. So much possibilities to test while I have too much to do already.

Alternatively I’ll use a cheap copper based ablative paint and use it as an additive. I am looking at the price of cuprous oxide and it may be cheaper to just buy that paint at $200 per gallon.

[I14]

Sorry to be a killjoy but it's probably not compatible with a solvent based ablative. I have made a 2K waterbased hard cuprous oxide A/F that did well on my raft but have never tried to commercialise it. It uses a water micible isocyanate as the Part B