T&T: Fw: Bottom Paint Additive Maybe?

[Larry N. Brown]

> Also, someone mentioned adding copper powder to bottom paint. Actually the
> active  ingredient is cuprous oxide, not just copper powder. Again, 
> messing
> with those guys' formulations can be iffy at best. You could always just
> sheath the boat with copper... that would work well but kinda impractical.
> If you were building a metal boat, you could use copper/nickel alloy, 
> which
> is expensive but intrinsically anti-fouling.
>
> Ok, it's 0148 and I'm up smoking a turkey for Thanksgiving... ya'll have a
> great turkey day!
>
>
> Keith

<SNIP>

When we had Cigano on the hard to do the bottom work a few years ago, we 
discovered a series of very badly done bottom paints. Yes, paints. Had to 
peel the bottom. Went back on with a barrier coat, well known here in 
southern Louisiana, used frequently on boat bottoms but originally 
formulated as a liner of reaction vessels in refineries.

At the time, the yard was employing a bottom painting technique which 
involved spraying the bottom with epoxy and then shooting the copper powder 
directly into it. I've seen two boats which have 3+ years on them and they 
look GOOD. Time it came around to do my boat, we used Copperpoxy, a paint I 
think that no longer is available in the US and Canada. It was essentially 
copper powder-- as opposed to cuprous oxide-- suspended epoxy. By suspended, 
I mean it was already in the paint can- took a lot of stirring to get it 
into suspension. Had to mix in a catalyst and a thinner. It sprays on with a 
high millage. The manufacturer's rep is talking 8-10 years. If I get 4-5, 
I'll be happy.

It doesn't resist all grass and barnacles but they don't stick. A year's 
growth all comes off with a pressure washer. I envision one Sunday afternoon 
a month in the tropics with bronze wool and my SCUBA gear to make the bottom 
look like a new penny.

Recently did the bottom of my dink in a similar fashion. Powdered copper 
mixed into epoxy and rolled on.

Here's a link that you might find informative:

http://www.epoxyproducts.com/copper4u.html

Regards,

Larry and Teri
M/V Cigano, 47' Prairie Sundeck Cruiser
Lying: Covington, LA - but not for long
N 30 26.7
W 90 07.1