What is the Best Anti fouling Paint

[Gallivanters]

JOTUN Bottom Paint!

I'm certainly no expert, but...

I applied two coats in Papua New Guinea in June, 1997. I hauled out two years later in Guam and didn't even have to pressure wash the bottom! It was hard as the devil to remove (for a barrier coat).

I then applied DEVOE paint before launching and I was disappointed to see it started to allow growth in three weeks!

Next haul-out was in Malaysia in Oct, 2000, where I re-applied JOTUN. We then sailed across the Indian Ocean, up the Red Sea, across the Med and across to the Caribbean. The boat stayed in the water until Oct, 2004 and the JOTUN was still working fine - not one barnicle & little growth - no scraping required - all the bottom needed was a good pressure wash and light sanding! I was able to purchase a 5 gal can of JOTUN in Puerto Rico and delivered to St Thomas for $425 total.

Few people in America have heard of JOTUN paint - but I will never use anything else as long as it's available.

Happy Painting!

Kirk

[hellosailor]

Kirk-
"The Norwegian paint manufacturer Jotun is one of the world's largest producers of TBT-based ship bottom paint." That's why it works so well. TBT based paints are also illegal in most of the EU and US because it is such a potent toxin, remaining in the water and killing off the bottom dwellers as well.

[JordanB]

GordMay
You say high dosage rates of H2O2 are required:
Dosage rates of 10%/volume (2-3 hours exposure time), or > 30% for contact
Does this mean that the 3% first aid kit peroxide doesn't disinfect cuts etc?

[GordMay]

Disclaimer: I’m not a medical, biological, nor chemical professional; but yes, I am implying that 3% peroxide isn’t a very effective disinfectant.

3% Hydrogen Peroxide is slightly effective against microorganisms such as bacteria, viruses, and less effective against fungi (slime). This low grade H2O2 is much less effective against more robust organisms, such as grass & barnacles, hence the stronger solutions I cited.

In industrial applications (cooling towers, etc) H2O2 is seldom used, due to the cost of maintaining the 30 - 50% reagent-grade solutions required to be effective against slime & bacteria, in closed systems, where physical dispersion and photolysis are not significant factors.

The ePaint website is not very informative - it doesn’t indicate the mechanism by which the H2O2 is formed, at what concentrations, nor specifically how it works against fouling organisms.

I don’t find unsubstantiated manufacturers claims particularly persuasive; hence, I must apply my very limited industrial experience, which leaves me initially skeptical of it’s efficacy. Further evidence or explanation would be appreciated, and might be persuasive.

HTH
Gord

[Intentional Drifter]

Just a hypothesis, here, but I'm guessing that when using a peroxide as an antifouling paint, one only needs to have a concentration sufficient to ward off the critters from settling themselves on the boat -- setting up an unpleasant environment so they'll take off, elsewhere. The concentration needed for that may be much less than what would be needed to actually kill the critter, especially given, as Gord points out, that it is an open system, I doubt that such a concentration could even be achieved without perhaps literally pouring the stuff into the water. Even then, it wouldn't last for long.

I agree, I'd like to hear more about it, and actually see some data. ePaint says that Practical Sailor did a test, but I haven't seen that and I don't seem to have that issue -- put that on the list for the library.

ID

[GordMay]

ID makes a reasonable supposition, that the H2O2 only has to create an “unfriendly” environment for attachment, not a “toxic” medium. I’m still uncertain that their product will do (even) that.
Perhaps ePaint should hire ID to help with writing ad’ copy.

[colemj]

The other possibility is that the local concentration is indeed high enough to kill. By that, I mean the microenvironment existing between the paint surface and the organism. Local environments can be very different, as witnessed by tooth decay, crevice corrosion, etc.

Mark

[hellosailor]

Gord, fwiw there was some talk about using peroxide on wounds some years ago and last time I heard, it was now being suggested NOT to use the regular 3% stuff for routine disinfecting because it was still strong enough to kill healthy tissue, which in turn left nice dead tissue where an infection could breed from the remaining critters. OTOH it was noted that for deep wounds which needed to be rinsed and then sealed, it was still a good choice because that "total kill" was needed to clean them out before sealing them up. Something to note (and check the current thoughts) for first-aid uses.

I'm not sure I'd believe in any peroxide-producing paint. The stuff just breaks down SO rapidly, I can't believe any paint could produce enough of it to last any real time. Somehow the paint is going to be so full of extra hydrigen atoms that it can "convert" the water next to it? For days and weeks and months on end? Just doesn't feel right. Feels actually exactly like the "magnetic fuel savers" that also were endorsed as being "In use on USN and USCG vessels milspec etc..." and it turns out those WERE approved by the military. But the approval spec was one that said "This device will not fall off the bulkhead of fall apart in normal use" literally, and had nothing to do with whether they DID anything beyond that. DoD was "required" to test them and issue the approval, and most folks never bothered to find out what it did or didn't mean.

[GordMay]

As hellosailor points out; Hydrogen Peroxide is no longer a recommended antiseptic*1 for use within wounds, although it is still used as an effective surface disinfectant*2.

*1 Antiseptics kill or inhibit the growth of microorganisms on the external surfaces of the body - they disinfect the skin.

*2 Disinfectants destroy vegatative microbes (bacteria, fungi) and viruses on surfaces, medical equipment and other man-made objects.

This would be a good topic for the “Medic” thread.

[hellosailor]

Very interesting, Gord. I never knew the two terms were defined (split) that way. That's what I get for skipping med school and going right into practice!<VBG>

[Ron_Fran]

We have pulled Questeria and are getting ready to paint the bottom. We have bought Trinidad SR (at $220 a gallon), but currently have an ablative paint. We a paying someone to sand it using 40 grit paper. She says that we will be okay if we have her apply two coats Seahawk 1277 barrier coat primer ($50 a gallon) after it is sanded. Does this sound reasonable, or should we exchange the Trinidad for a high quality ablative paint.

Thanks, Ron

[S/V Elusive]

Ron - Three years (plus a few months) ago, I sanded off the ablative paint that had been put on my boat a three years prior to that. I then directly applied 2 complete coats of the Trinidad SR, and one additional coat along the scum line and leading edges.

My diver says: Coverage is still "Excellent" and Effectiveness is "Excellent to Very Good".

My bottom is 1980's vintage fiberglass.

My suggestion is that after the 40, you use a 100 (or so) to fair it a bit, and, of course, fill any nicks and such. You didn't mention if you had experienced blistering and I'm assuming your hull is F/G.

Apply the SR directly.

good luck

[Alan Wheeler]

Never used it and now I see why. $220/gal, ouch!! It better damn good.
Here's the official info on it. http://www.pettitpaint.com/pet_cds/t...trinidadsr.pdf

[S/V Elusive]

At West Marine - it is (was?) $200/gal retail. I suspect that the $220 is the markup at the local boat yard? It can be purchased with a Port Supply Card at WM for about $160 USD a gallon.

[Alan Wheeler]

I think I just paid NZ$34/ltr US$21./ltr for AF3000. How many ltrs to your Gal???