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...
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 shit"!
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