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Old 18-05-2012, 06:53   #1
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Copper loaded gelcoat products

I was asked a question about this in another thread, about a specific product, but thought I'd pass on my experience here as well...

Roy,
I haven't used this "particular" product, but...

When we were still in the building process, we used a product similar to this in keeping with our environmentally aware beliefs, and in hopes of a LONG service life. Like several of our environmental "experiments", this one didn't pan out.

There were many such products available at the time (Perhaps 6 or 7), being tried by different companies. They were ALL basically copper powder in pure epoxy resin, with minor differences.

A number of our multihull building friends tried different brands around that time too. NovaCote, EpcoTec, Copper Clad, WEST System's powder, etc... We choose CopperPoxy, which had changed hands, right after we bought the first batch. The new company immediately switched the copper powder to a copper flake. This turned out to be a disaster! Read on...

We put on about 18 or 20 mills, (This was more than needed), then sanded about half of it off to get it perfectly flat and level, then polished another 2 off with 220 grit. We had a gelcoat smooth copper coat, about 8 mills thick, that looked JUST like a new penny! I figured that IF this solved the problem for 15 years, it was worth the months of work and the considerable expense.

After launching our bare hull, (first 2 years in the water), we were living in the high growth waters of Beaufort SC. At first I only had to scrape the hull every few weeks, but VERY soon it was EVERY week. Each time, the barnacles would be about the size of a large pea, and the infestation was worse near the underwater metal. (Shaft, prop, strut, rudder hdw, and copper grounding plate. Everywhere, they were REALLY stuck!

This was when I realized that copper "sheet" isn't really a deterrent, and in reality, ships used it mostly for boring worms... The copper plate had the most growth! (Copper works in bottom paint, because of the sloughing off of the paint, the breakaway nature of the very surface layer, and/or constantly presenting new copper to the barnacles).

I had bonded these metal parts internally, (as in ABYC), and later, upon Stan Honey's advise, separated the copper grounding plate from the others, as well as from the boats AC & DC systems. This helped.

It turns out that small currents, from different metals, attracts barnacles like mad! I was an ABYC member at the time, so took my books & the "Galvanic compatibility" apparatus, to check for a problem with my chosen metals. There was none. They were close enough on the galvanic scale.

The growth was all over the boat, but FAR worse near these metal part areas. (only about 30 or 40% of the main hull).

This area was a disaster. It attracted barnacles like mad, and NOWHERE could they be wiped or scrubbed off. They attached in a way totally different than on bottom paint, which actually gives up a microscopically thin piece of itself, when you remove well attached barnacles. The CopperPoxy did NOT, so the critters, (grape size in 10 days), had to be chopped off with a stiff, sharp, blade. It was a nightmare!

Between the scuba tank fills, and this weekly chore, it ate up a day of the week, for our entire first 2 years. (The second year was in Titusville FL, which was a bit better, but similar).

I am a good diver, and was VERY fit, but even with multiple tanks of air, any attempts to wet sand a new surface, underwater, was a waste of time. I only got about 1' done!
You just can't press hard enough.

By this time, I had gotten feedback from my boatbuilder friends in various parts of FL, and ALL had come to the same conclusion. "It is a flawed concept", and NONE of them work! They ALL painted over the stuff with bottom paint, saying: "What a relief to be rid of that useless ****"!

It was my turn, so I went across the Gulf of Mexico to the Pensacola Shipyard, for my first haul. After VERY thorough prep, I put on 3 coats of Trinidad, and launched. Then, 2 weeks later, when I dove on the boat, I was shocked that in that 40% of the main hull "problem area", ALL of the paint had peeled off.

Thinking it was perhaps from rain, when in the yard, we just did these areas over, with an epoxy barrier coat in places, and set out for Central America.

When we came back, 7 months later, it had happened again. Then I realized what was going on. Because of their copper FLAKES, vs powder, my chosen brand of copper loaded gelcoat, (under the barrier coated bottom paint), was ever so slightly electrically conductive! SO... unlike the other brands, which were also "nada" as an antifouling, MY brand could NOT even be coated over, near the underwater metal, with ANYTHING. In these isolated areas... It had to be ground off, with 36 grit, then a new barrier coat was put on this repair before bottom paint.

TWO hauls latter, the repair area was made larger, then larger still, until I was WELL beyond the underwater metal.

It has now been over 10 more years, and bottom paint sticks fine. 80% of the boat's bottom paint still has CopperNadda under it, with no ill effects. It DOES make a good hard barrier coat. The problem area, became "NO problem", after removing it entirely, barrier coating the hull, and bottom paint.

ALL of these companies selling wishful thinking "snake oil", have gone belly up, (Most of them in just a few years). Only MY brand was a problem painting over later, (due to the flakes), so for most, painting over it was an easy enough solution.

For a full time in the water "cruising boat", this is a flawed concept. None of them stood the test of time from '85 to '95, and I doubt that this new brand will either. I wouldn't touch it with a 10' pole!!!

For small trailerable daysailed, or beachable boats, and dinghies, it would make a good HARD and tough bottom for dragging the boat on, and if wiped well weekly, and re-polished once a month or so, might offer a bit of antifouling in low growth areas. I liked it on my Kledgacell dinghy just fine.

BUYER BEWARE!

M.
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Old 18-05-2012, 06:56   #2
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Re: Copper loaded gelcoat products

And a few more...
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Old 18-05-2012, 07:09   #3
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Re: Copper loaded gelcoat products

I think one thing to remember here is that conventional bottom paints do NOT have "copper" in them, they have cuprous oxide, which is to copper as rust is to steel. It is much more toxic, and much more able to transmit itself from a surface into an organism to poison it. So copperpoxy et al is a truly foolish idea, as is putting copper powder or flakes in a conventional bottom paint as some do. It's just not the same thing at all. The cuprous is constantly leaching from the surface and poisoning the hell out of everything around it, while copper is pretty much totally inert.
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Old 18-05-2012, 07:55   #4
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Re: Copper loaded gelcoat products

Quote:
Originally Posted by minaret View Post
The cuprous is constantly leaching from the surface and poisoning the hell out of everything around it...
Your description of how traditional anti fouling paints work is accurate, if not a little lurid. Any boat owner in California will tell you that cuprous oxide dosen't "poison the hell" out of anything. It is effective at retarding fouling growth (especially hard growth), not eliminating it.
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Old 18-05-2012, 07:59   #5
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Re: Copper loaded gelcoat products

Thanks Great article.!
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Old 19-05-2012, 10:04   #6
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Re: Copper loaded gelcoat products

AFAIK CopperPoxy is designed as a bottom paint, not a gelcoat. Very different things.

I've seen one of those products work very well one season, fail totally the next. Needless to say it was back to bottom paint after that.
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Old 19-05-2012, 10:25   #7
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Re: Copper loaded gelcoat products

Quote:
Originally Posted by hellosailor View Post
AFAIK CopperPoxy is designed as a bottom paint, not a gelcoat. Very different things.
Copperpoxy is not a "paint". It's a copper-loaded epoxy. Very different things.
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Old 19-05-2012, 10:30   #8
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Re: Copper loaded gelcoat products

I know that epoxy isn't paint, even paint isn't paint. The folks who make it prefer to call it a "coating" because that justifies the $300/gallon prices.

But Copperpoxy *is* sold as/for a bottom "coating" aka bottom paint. gelcoat is the stuff the cures in the absence of air (as epoxy will) but is used when you lay up inside a female plug to build the boat, typically. Typically, gelcoat is not applied afterwards on a completed hull. Coatings, aka "paint", are.

Now I suppose the folks at International are going to come and reposses my "coatings" because I called it "paint".<G>
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Old 19-05-2012, 13:16   #9
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Re: Copper loaded gelcoat products

All anti fouling prints are hull coatings but not all hull coatings are anti fouling paint.
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Old 19-05-2012, 17:58   #10
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Re: Copper loaded gelcoat products

Quote:
Originally Posted by hellosailor View Post
I know that epoxy isn't paint, even paint isn't paint. The folks who make it prefer to call it a "coating" because that justifies the $300/gallon prices.

But Copperpoxy *is* sold as/for a bottom "coating" aka bottom paint. gelcoat is the stuff the cures in the absence of air (as epoxy will) but is used when you lay up inside a female plug to build the boat, typically. Typically, gelcoat is not applied afterwards on a completed hull. Coatings, aka "paint", are.

Now I suppose the folks at International are going to come and reposses my "coatings" because I called it "paint".<G>


No, they never called it "gel coat", nor a bottom paint. It could,however, be used in a mold, (like gel coat), in the total absence of air, if one was set up for it. It was a 2 part epoxy resin... I used gelcoat as the closest word to describe it. Our Searunner trimaran is self built and glassed with epoxy resin, then 4 top coats of epoxy over that. It is not gel coat either, but serves the same purpose of providing the surface a tough outer skin. Our epoxy has the advantage of being a 100% solids, water "vapor" barrier, where as a true "gel coated" polyester FRP boat is not. This is why they can get blisters, and our epoxy glassed hull can not.

Our epoxy glassed hull, however, MUST be protected from the Sun's UV rays, so we keep LP paints on her for that, (above the WL).

CopperPoxy, and all of the other brands that were "once" available, were not at all bottom paints, as they were just epoxy resin, that sets up hard from a 2 part chemical reaction. This resin, was just like what our boat is built with, except it was then mixed with copper, in powder or flake form.

It made an opaque, HARD, gel coat like bottom, except MUCH harder, and was only as smooth as I described, because I faired and sanded it to that condition. It rolled on very rough like "orange peel".

SO... after about 200 hours of work, It looked just like copper colored gel coat, was actually much harder, and was permanently bonded to the hull, just like gel coat.

What all of these products share, is the flawed concept that the copper powder that was buried in the resin, OUT of contact with the water, was providing any antifouling properties. Only a small portion was on the surface.

The notion that a light sanding renewed the surface, was also flawed, as it would take a LOT of mills in the first place, frequent hauls, and SERIOUS sanding.

Then there is the point that was previously made about Copper, and Cuperous Oxide, being very different. One repels barnacles, and the other doesn't... At least not much!

Sorry if my use of the word "Gel Coat" was an over simplification.

M.
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