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Thread: copper bottom

  1. #1
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    copper bottom?

    Has anybody ever used Copperpoxy? How did it work for you?

    Interested skippers will find google useful for research. The company website is particularly not useful and I heard a rumor that they had run into trouble. Copperpoxy is an epoxy coating (not a paint) that could be applied as a barrier coating to a prepared hull. Because it does not slough and is not ablative it is touted as environmentally friendly. I'm for that. It was not wallet friendly when I looked at it a few years ago. ($200/300 a gal ???)

    Guys on the forums rate it as Fair, generally. Some say it is a cold water bottom, no good for the tropics. It was good keeping hard growth off but soft growth and slime acted as if it wasn't there. Many thought the process and expense wasn.t worth it. Environmentally friendly skippers gave it better marks - the soft stuff brushing off easily.

    .................................................. ....................................

    Been working on 338's bottom. Have applied a white epoxy ungelcoat over the reworked hull, in the form of a potable water rated Novalac tank coating. When I learned how, the Third coat went on easy, cut with a little xylene. It took three coats to get a 100% barrier coat finish using a roller. Impossible to brush on.

    Over that been rolling on Paul Oman's (epoxyproducts,com) answer to the stuff above - but you have to experiment with it - using his clear Low V epoxy and copper powder. I've got three coats of that on. And I think I'll just continue for a while. Again, it took getting to the Third coat befor it went on like a dream. The copper goes on SMOOTH and tight and level. The key is ambient temperature and amount of powder.

    It gleams like a iridescent new penny and looks extreme. These coatings the way I apply them go on not too many mils thick. But rolling it on evidently is the only trick, we'll continue for awhile. Thin coats don't cover no sins. After six coats overall the factory incised waterline still shows. New WL 6" higher.
    Since these are all epoxy coatings (not paint) it's all barrier to me.

    So haul out COULD be nothing more than wet sanding and putting it back in the water.
    The more coats the better therefor, right? One forum reported that when you do put ablative over it, that regular bottom paint works longer and stronger.

    I bought the quantities in a package epoxyproducts offered, (may have doubled it) have probably enuf for Three coats on a 50' trawler. Copperpoxy advertises 60% copper (one guy called it "putty") - my personal extensively researched easy to apply formula works out at 25%.

    Even if it don't kill everything under the boat, we had the satisfaction of admiring Alberg's beautiful BEAUTIFUL sculpted Ariel bottom dressed to kill. SO NICE!!

    Anybody?
    Last edited by ebb; 10-04-2004 at 11:55 AM.

  2. #2
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    I think Copperpoxy would be more popular if it were any good.

    The only experience I have with Copperpoxy is helping someone to apply it to their boat. The stuff is real thick and gritty. You can't get a nice smooth bottom with it. Maybe if you sanded it down, which would be a waste of costly product.

    The method you're using with epoxy and copper powder sounds better.

    Around here, boats are hauled every year so hard growth is not a problem. The problem is slime buildup. The slime-blocker paints don't stop it. You just have to scrub the bottom once or twice a season.

    Its amazing how much faster the boat moves after you give it a scrub.

  3. #3
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    Lo there, C'pete,
    This same cold water company (based in Seattle!) sells a paint-on slime in a can too. Trouble is: slime grows on slime.
    I don't know if there is interest enough to create a consensus here just about how useful copper dust encapsulated in epoxy IS. There has to be some actual reported experience. There are no studies, which is what the company should have done. There are only forum posts, and we (me, anyway) have to add a lot of salt to what people say. It's probably the same salt you have to add to what a company says about their product.

    My first coat ended up with wooley bits all over the surface. I seived the copper powder and found no copper wool. Next time when I pulled the metal-mixer out of the epoxy, There were these wooley strings. I had been peeling the sides of the plastic bucket while really concentrating on how well I was combining the two parts. Henceforth I ran the mixed Low V through a medium mesh painter's strainer. Mixed the powder in with a paddle.

    You sometimes hear about straining paint 'even if it doesn't need it.' The result is smooth, flawless, and fabulous. Certaianly in the copper of 338.

    Dry sanding copper coating is pretty futile because the grit immediately gets pockmarked with product. Hell, I wasn't going to get messy with water and emory cloth! In the beginning I took breaks to flick these tics out of the grit. most were loose. That got old, thumbnails wore down, so ended up sacrificing a number of 80 grit disks folded over and used by hand. Tedious, the plastic bits were all over the bottom! The best reward was that the next coat disappeared these pimples well. Holding at three coats, the problem never happened. So watch those metal mixers in plastic buckets.

    The copper goes on flawlessly (so far) And I'm going to apply each new coat over dry without sanding prep. It's all going to come off someday anyway.
    The question is: how many coats? Twenty, thirty?? Same satisfaction every time!
    Last edited by ebb; 10-04-2004 at 06:10 PM.

  4. #4
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    Talking My solution for the bottom slime

    This works fine. I haul the boat once a year here in the temperate zone's personal Hell, rife with floating crap and hull-sucking mullet. All it takes is a 152.00 bill. Though I will be floating a much larger bill for the yard birds to slap a can of Trinidad on the hull later this year.
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  5. #5
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    George,
    Perhaps this whole negative trend of painting the bottom with poison could be reversed by slathering whirled sushi on, Tokyo instead of Trinidad, something the 'hull suckers' would graze clean like locusts.

  6. #6
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    Thumbs up 338 copper bottom update

    It is eight coats by now: three of white ungelcoat and five of copper powder mixed into clear epoxy coating - the tape line is getting a distinct edge, the bottom is building up. I'm also increasing the powder a little each time. Doing one side at a time under 60 degrees, very easy.

    Wiping new coating (couple days old) with an alcohol moistened rag gets a copper telltale, not much, but definite, there is exposed copper in the epoxy coating.

    ----------------------------------------------------------------

    But, for whom will try this more friendly bottom: I missed one day, a warmer day, so it had time and heat to cure harder, when I took the 80 grit to it, a closed grit belt material, I easily sanded out the standup bits and got dust instead of copper build-up on the abrasive. Cloth backed abrasive is usually tough stuff. I separate a small piece from the belt, folde it in half, and lightly scratch the surface knocking the tops off the bits. So to say, this stuff is sandable DRY. Sanded the whole side with a single piece.

    When 338 goes in, I'll give it one last scratching and keep a log on what happens in the briney.
    Last edited by ebb; 10-08-2004 at 03:26 PM.

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