We're about to repaint the bottom of our 50' boat with an ablative
paint that, as far as we can tell, doesn't contain any biocide other
than the copper content (which is pretty low, about 25%). We'd buy a
better paint, but that's all we can get where our boat is, in Turkey.

Are there biocides that can be added to bottom paint to keep the slime
off? The ones used in commercial paints don't seem to be available by
themselves. We've heard of people using tetracycline and even chili
peppers, but don't know if there's any real data to support those, and
besides, don't have a clue how much to use. Any ideas?

"Akka" wrote in message
oups.com...
We're about to repaint the bottom of our 50' boat with an ablative
paint that, as far as we can tell, doesn't contain any biocide other
than the copper content (which is pretty low, about 25%). We'd buy a
better paint, but that's all we can get where our boat is, in Turkey.

Are there biocides that can be added to bottom paint to keep the slime
off? The ones used in commercial paints don't seem to be available by
themselves. We've heard of people using tetracycline and even chili
peppers, but don't know if there's any real data to support those, and
besides, don't have a clue how much to use. Any ideas?

I have a friend that adds a pound of Cayene pepper to each gallon of
cheap (Red Hand) bottom paint. Lasts 2 years with no problem. Don't
know how it would work without the pepper.

Doug

Check your local paint store for "mildew additive" or something like that.
It's the same tri-butyl tin that used to be in boat paints. You can also add
Starbrite's compound X (tetracycline) and Cayenne pepper. I've added both to
my old dinghy paint formulations and they do work. I think I used about 1/2
oz cayenne per quart of paint. Mix it up in whatever carrier the paint uses
first (water or solvent).

--


Keith
__
Black holes suck!
"Akka" wrote in message
oups.com...
We're about to repaint the bottom of our 50' boat with an ablative
paint that, as far as we can tell, doesn't contain any biocide other
than the copper content (which is pretty low, about 25%). We'd buy a
better paint, but that's all we can get where our boat is, in Turkey.

Are there biocides that can be added to bottom paint to keep the slime
off? The ones used in commercial paints don't seem to be available by
themselves. We've heard of people using tetracycline and even chili
peppers, but don't know if there's any real data to support those, and
besides, don't have a clue how much to use. Any ideas?

In my yard where the endless refit of Flying Pig is slowly progressing, I
encountered a wood-boat cruiser; he'd built it himself.

He made up his own bottom paint each time he hauled. One part paint, one
part ground copper dust by volume, and about half that of cayenne pepper,
which yielded about two parts liquid volume. He routinely got at least 3
years from it, and his bottom was sparkling when it came out, so his
standards of "getting" 3 years apparently is a great deal higher than mine
would be.

FWIW and YMMV but it worked for him

L8R

Skip and Lydia, refitting as fast as we can

--
Morgan 461 #2
SV Flying Pig
http://tinyurl.com/384p2

"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail
away from the safe harbor. Catch the trade winds in your sails. Explore.
Dream. Discover." - Mark Twain
"Akka" wrote in message
oups.com...
We're about to repaint the bottom of our 50' boat with an ablative
paint that, as far as we can tell, doesn't contain any biocide other
than the copper content (which is pretty low, about 25%). We'd buy a
better paint, but that's all we can get where our boat is, in Turkey.

Are there biocides that can be added to bottom paint to keep the slime
off? The ones used in commercial paints don't seem to be available by
themselves. We've heard of people using tetracycline and even chili
peppers, but don't know if there's any real data to support those, and
besides, don't have a clue how much to use. Any ideas?

Thanks for all the input. We discovered one additive that might be even
more effective than cayanne pepper. It's called Omadine, produced by
Arch Chemicals. There are some test results available on the web, and
they look pretty good. However, in the end we didn't follow any of the
great advice we got here, because we found a tin-based self-polishing
paing here in Turkey. And we bet tin is best.