Doctoring bottom paint... any feedback?

[Bob Cleek]

Ah, welcome back, Chemist. You were missed...

Here's the question. Out here in Sunny California, the land of fruits and nuts, they've made laws that require leaving out all the really deadly stuff that used to be in bottom paint... you know, the stuff that made it work. Now, you get paint with copper in it, and that's about it. There's any number of schemes to doctor up bottom paint to give it more killing power. The copper has some effect on fauna, I'm sure, but it does little to deter flora. Some swear by cayenne pepper, but that seems kind of wierd to me. I'd think it would decompose in short order in the water, being a plant material. I've played with adding Di-Al, which is tributyl tin in a mineral spirit base, sold for adding to house paint to retard mildew. What have others tried and did it make a difference? (How might you tell... pretty subjective test protocol, but...)

The question for Chemist is (purely hypothetical), assuming your basic oil based decent quality copper bottom paint, 1) what did they used to put in it that made it work better than now, 2) can you still get that stuff and mix it in yourself, and 3) what can you put in bottom paint, if anything, that really, on a scientific basis, retards marine growth?

Since this is a purely hypothetical discussion, those who have opted for iron ballast keels so as to avoid exposing their barnacles to the horrible enviornmental effects of lead need not chime in to warn us of the tragic impact of bottom paint on the ecosystem.

[David]

Bob,

I wish you'd shut the heck up about the Di-Al -- they'll ban it if the news gets out. Something that I definitely don't do ('cause it's illegal) is paint my outboard motor underwater section (I leave it in the water) with simple oil based primer that has two bottles of Di-Al dumped in and mixed. This makes enough for many seasons and costs about $6.00 (paint is left-over). The legal alternative which everyone definitely should do is either buy from Waste Marine, for $30.00, the crappy spray cans of Sn-based antifouling that is legally sold for outboard motors because Cu-leads to corosion of the Al housing that outboards are made of or pay (about $100.00) to a licenced marina to paint your outboard for you with, yes, (bis)-tributyl tin based antifouling paint. Of course, since all three methods leave the same Sn-based residues in the water that cause animals of the phylum Mollusca to grow penises ('tis true) the environmental impact (assuming you don't discard the waste paint in the ocean) is identical. This kind of lawlessness seems almost acceptable. By the way, if I were to mis-use Di-Al in this diabolical way, I have a strong feeling, a vision really, that it works fine especially if given a second coat mid season.

David.

[Ed Nye]

Hey folks, we been through this before, take a look:

http://media5.hypernet.com/cgi-bin/UBB/ultimatebb.cgi?ubb=get_topic&f=1&t=002023&p=

Ed

[Alan D. Hyde]

Felix Riesenberg's classic "Standard Seamanship for the Merchant Service" has lots of nice old paint recipes at the back.

Most contain carbonate of lead or red lead, and some (I think) also contain mercury in small amounts, as well as some other poisons.

What the law permits? I have no idea. BUT, Bob, this is a book that (if you don't already have it) you might enjoy getting. Lots of practical wisdom circa 1922 or thereabouts...

Alan

[ 06-20-2002, 10:30 AM: Message edited by: Alan D. Hyde ]

[Bob Cleek]

Okay, okay... David... not another word about *****! Your "suspicions" confirm my own. So far, that's the only thing I've been sufficiently "suspicious" about. Just checking to see if others had the same suspicion.

Thanks for the tip, Alan. I'll have to keep an eye peeled for that book. I suspect that a lot of those old paint recipes are really all the commercial paint companies are still using today. It's not like any of us are going to make our own paint, but if you know how it's done, you can tweak the commercial stuff a bit with some confidence.

[Pelican]

Folks can say what they want but I am a believer in pepper. When I acquired DOLORES CATHERINE we did her botom with some commercial bottom paint that was so old the can was rusting apart. It was supposed to be red but a test patch showed it was going to be "pink" :eek: . I added a gallon of Pettit in blue and changed the color enough to tolerate. With the gallon added it brought the old paint back up to about 4 1/2 gallons. To this we added 24 oz of cayenne and mixed well with a paddle in a drill.
She sat in the water, Alabama Gulf Coast, from Aug 2000 until I pulled her in April '02. There were no barnacles on the hull. The rudder and rudder shoe had not been painted with this but with only straight Pettit bottom paint. They were encrusted with barnacles.

I redid the bottom paint while I had her out only this time I used about 2 lbs of ground habernero (sp?) in five gallons. When I was mixing it my eyes watered and my nose started to run. I got a bit on my forearm and didn't get it off right away - it dried and blistered me. Anything that can eat into that stuff deserves the meal. :D

Oh, as a test I did the rudder and rudder shoe with Pettit and mixed in cayenne. Just want to see the difference when I pull her again.

[wolfietuk]

Just consider these laws to be the full employment act for boatbuilders and painters. Maybe you can add an extra rail or lift and a couple of employees. Wow dont you just love your government.

Rick

P.S. I picked up a couple copies of the Federalist papers at Barns and Noble. They were on the discount rack, I guess no one was interested. 9.99 for a big hardbound book. A good gift for those going off to college.

[Cedarhill Boatworks]

If adding the pepper to the bottom paint does indeed invoke these strong reactions in humans, runny nose, burnt skin etc., how do you propose to clean the bottom when it comes time to repaint? I am not questioning the validity of the claims, I just want to know what happens in the yard when you start grinding this stuff off and it becomes airborne dust?

[Hughman]

Pelican wrote:

some commercial bottom paint that was so old

Pelican.....It was the "old..commercial" mixture that might be so effective. I'd like to know the results of the pepper in the plain paint. Cedarhill makes a good point, too. I have, lets say, less than fond memories of bottom paint removal. Where did you get 2# of ground Habanero pepper? What did it cost? And who got the job of grinding it up? Did they live? (I have a profound respect for habanero pepper...) :eek:
David, It's my understanding that the commercial and military vessels use TbT in the same effective formula that is prohibited to recreational vessels. I imaging that the total painted area on commercial/military/foreign vessels far exceeds that of recreational vessels.

[Alan D. Hyde]

Bob, I went back to my original post and spelled Riesenberg's name right, and put the word "Standard" in front of the title, which makes it right. Van Nostrand was the publisher, and it was 1922.

Most people here would enjoy reading it.

Lots of practical knowledge from an "Unlimited Master" in sail and steam...

Alan

[Art Read]

Met a guy once who was halfway through his circumnavigation aboard his homebuilt, ferro-cement sixty foot schooner. He had "contacts" in the navy who'd "aquired" for him a barrel of that black bottom paint you see on all military vessels lately. He didn't know just what was in it, but it scared the hell out of him. Seven years later and even slime wouldn't stick to the stuff. He also noticed sealife dropping off the pilings if he stayed at one slip very long. Not sure I'd ever want to grind that stuff off... Wonder if that's part of the reason it costs so much to scrap Navy ships?

[Cedarhill Boatworks]

Anyone whos been in the NAV will tell you that all of the paint and coatings they use are so far over the top where toxicity is concerned. Even the plain old grey that we slapped on everything that wasn't polished was scary stuff.
The question is do you really want to have it on your boat? And do you really want to ever have to grind it off?
Thats where the pepper idea makes me a little nervous. If you use it, and it works as well as the testimonials say, do you warn everybody in the yard before you start sanding away? And if not, and the guy three boats down starts going into shock because of the dust that you are creating how much of an alpha hotel are you going to feel like? I always werar a real rspirator with good cartridges when I'm sanding. That doesn't protect the other people around me who may be doing nothing more dangerous than painting or polishing or whatever else. seems less than fair to introduce another nasty element to the already fairly toxic atmosphere in the average boatyard, especially one that no one else is prepared for.

[John B]

Might be a case for using it in an ablative type where you can waterblast off rather than sand.

[thechemist]

Ed pulled up a good thread about stuff and things. I would add to this discussion that capsaicins [the class of chemicals in peppers] have shown up here-and-there in the patent literature as having deterrent properties for marine life. There were other threads [likely found by searching for the word CAYENNE in one or another of the forum categories] that discussed cayenne pepper, a readily available pre-powdered commodity easily incorporated into antifouling paints.

Some two to eight ounces per gallon should do.

There is no reason one could not add a few ounces of bis-tributyl tin oxide, also. It is good for preventing mildew and for all we know, preventing underwater mildew might make the antifouling paint last longer.

[Dave Hadfield]

Di-Al? Where do you buy that? Is that trade name?

[Pelican]

When it comes time to repaint I'll do what I did last time. Pressure wash and paint over what is there.

[mariner2k]

I checked into a product that is sold in marine stores. Starbrite puts it out, and it is added to bottom paint. The active ingredient is tetracycline (spelling?). From what i,ve been told tetracycline can be bought at livestock,farm supply stores. I have no idea if it works but of course Sttarbrite makes the claim.
Anyone ever here of this?
kevin

[JimD]

Tetracycline?? The only tetracycline I know of is a powerful antibiotic, probably used in live stock feed, used to be (maybe still is) prescribed in careful doses to humans. I took it for acne decades ago as a teenager. Oh well, the pimples went away...

[tjs]

If someone had time I bet you could search the web and find the specs for the paint the military uses. It might answer a lot of questions about the ingrediants.

[Concordia..41]

Go to the Bahamas and buy tin. Interlux ships it out of this country by the container full. The French started all this when they were killing their snails. Found out it was there sewers that killed the snails. The EPA jumped in and outlawed tin except for military vessels and aluminum boats. Other countries went back to tin, we never will.

You can also by freon R-12 in the old 1 pound can for $2.00. National in New Jersey manufactures it. We have to pay $28.00 to $32.00 per pound and have to have it installed. The last 30# bottle I bought cost $780.00 and that was two years ago.

Another thing is the new LP gas valve that will keep the tank from being over filled and exploding. I noticed down at the boatyard they still use the old valve on the 250# tank that they still fill every month. I guess a #20 is more dangerous than a 250# tank or was it time to take a Congressman on a vacation so you could sell all new LP tanks to the millions of grill owners? The local gas company will install the valve in my 10# tank on the boat for $48.50 but they have to re-certify the old and that is $20.00. New tank is only $56.00.

Dave

Sun over the foreyard

[ 06-22-2002, 05:01 AM: Message edited by: Concordia..41 ]