All I know is hearsay. It works in cooler waters, better the further north you are. No good in the tropics. Said to keep barnacles off in SFBay, but weed will form. Depends if the basin you're in flushes well. too. Brand name Copperpoxy (www.copperpoxy.com), said to have 60% copper powder in a two-part epoxy putty like material. It is rediculously expensive ($300 gal, no kidding). Make your own with 'Low Vis' epoxy and copper powder ($14 a #) at 1/4 to 1/3 the price from epoxyproducts.com. The site and the owner are user friendly and flog highend and safer material. The website is worth your time and a lot of fun.
I put three coats of potable water white epoxy on my mottled bottom, if later we get down to pure white, that's the 'gelcoat'. I thought it a great product and used it also in the belly tank under the cabinsole. A 100% solids material.
Now when it came to the 5 coats (I think) of made copper/epoxy I started with less powder and added more each time, up to 35% I believe. (Well the first coat was too thick and sticky and tore the rollers apart depositing sponge bits over the entire surface, easy to sand off but not recommended.) Low Vis goes off quicker than what I'm used to, but it worked out fine doing one side at a time. The effect it had is quite astonishing, after the second coat it was like a dog fight for the crowd it gathered in the marina. Shows how bored people can get!
Adding the copper makes the epoxy thicker, I just worked with what I liked to roll on without tipping and fast, FAST. The powder and the epoxy are the same weight, so there is no separation or settling out after mixing. After eight coats ( just kept going till the powder ran out, saved enuf for the rudder and those bare spots under the keel when the blocks were moved.), I don't think it's built up a 1/16th of an inch. But I always tried to add a little more on the stem and under the keel. And it is ALL barrier coat anyway. Did lite quick sanding between coats: scratching. If I put another coat on the next day I felt I didn't need to sand. Sanding knocks off pieces of the roller that get pulled off. This is what you adjust in your mixing to avoid - by the last two coats I'ld got it down!
I guess I'll see what happens at my first haulout. Supposed to hose it off and drop it back in. Maybe a diver can brush the growth off in the water. Cheaper? Do it by self? ScotchBrite pad scrub? Do know there is a fine barrier coat on 338's bottom. Copper/epoxy said to enhance ablative longevity and strength when you must paint. Will avoid sanding. But it would be fantastic not to have to ablative anymore!
Both epoxys mentioned here are 100% solids, no solvents. But I do keep a quart can of xynol handy. Tablespoons of the solvent will loosen up stuff too sticky or heavy, and may give a couple more minutes of working time. Mixed 24 oz per side, but don't quote me, it left some in the liner pan which just got hard and left in the pan for the next time.
[Notice in the upper left portion of the copper photo (Pg 11 - #156) a faint incised line caught by the light. That's the original scribe line in the gel coat showing thru, left there on purpose. That shows you can't hide no sins after eight coats. The white coats are very thin.]
Reply With Quote