Do barnacles prefer white antifoul?

I vaguely recall looking at the copper content of various paints to discover, as has been mentioned earlier, that white AF contains less copper than darker (or any other coloured) paint. This might only be evident with some paints (as some paints may have less copper anyway and thus white is easier to make with the same copper content). Its the copper the determines, and whatever biocides that are added, the AF properties - so I would check copper content. I note that Zinc is sometimes added - in Australia zinc is not considered an active ingredient (but can be white). So take care when looking at the formulation.

So far none of the experts have made any mention that any of these organisms have eyes and if white is more prone to fouling (in the same location) I'd look at chemistry first - its an easy option :)

Jonathan
 
lpdsn said:
Thanks for that informative post.

I wonder whether there would be any avenues that could be explored to use these chemical means to drive them off or to cause them to attach to some sacrificial item hung over the side, which could then be cunningly removed just when they think they're safe. I'm sure the paint manufacturers have already thought of this so I'm just curious about people's thoughts really.
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Commercial vessels may use an antifouling coating that doesn't allow the larvae of fouling organisms to become attached; "foul release coatings" is what to look for. They aren't used on leisure boats for two reasons - first, they don't work unless the boat is travelling through the water faster than a critical speed (about 8 knots or greater), and second, that they don't work if the boat is stationary for any length of time (they don't deter settlement, they make it impossible for the beasties to hang on, but once they are settled, they adhere pretty strongly - look up "byssus" to get an idea of the strength and adhesion of materials beasties use to adhere with). So they don't work for a sailing boat that usually travels at less than 8 knots, or any boat that spends most of it's time stationary (as ours do!). Commercial vessels, of course, spend most of their time moving at speeds well over 8 knots. Another reason they aren't more widely used is that they are reputed to be EXTREMELY difficult and costly to apply!

There is work going on to develop coatings that deter the settlement of larvae using chemical signals, but a) I don't know how near this is to commercial deployment and b) I can't say more because I am bound by confidentiality agreements. However, once again I suspect that this will have little impact on the leisure scene, as it only deters settlement; once a beastie has settled (even if it doesn't like it!), it will stay settled, and as Tim O says, they then secrete other chemical signals that encourage others to settle nearby! A constantly moving commercial vessel would see far more benefit than a sedentary leisure vessel. The other problem is that fouling organisms cover a vast range, from algae to crustaceans, with lots of other things as well. What deters a crustacean might well be fertilizer for algae!
 
When I first needed to antifoul my boat I chose the Hempel paint that was recommended as working locally. In the Chandlery I told the owner that I wanted to change the colour so that I could see where I had painted, and suggested using white. He said I should not do that and put two tins, one white and one either black or dark blue, on the floor and asked me to pick them up. The white one was noticeably lighter. He told me that the white antifoul contained less copper and would not last as long.
 
Interesting stuff!! Nelson's column...bloody hell...next time one of my non-sailing chums calls me "Barnacle Bill" I'll just give a knowing wink...

I've always used black a/f, and was told it was better for the simple reason that it's going to be darker under a black boat than a white one, so weed will grow more slowly. Kinda makes sense...
 
We use red as if we are ever upside down - it will stand out in the seas, or so a SAR helicopter pilot told me having searched for 2 inverted cats on an offshore race.

:)

Jonathan
 
AntarcticPilot said:
Commercial vessels may use an antifouling coating that doesn't allow the larvae of fouling organisms to become attached; "foul release coatings" is what to look for. They aren't used on leisure boats for two reasons - first, they don't work unless the boat is travelling through the water faster than a critical speed (about 8 knots or greater), and second, that they don't work if the boat is stationary for any length of time (they don't deter settlement, they make it impossible for the beasties to hang on, but once they are settled, they adhere pretty strongly - look up "byssus" to get an idea of the strength and adhesion of materials beasties use to adhere with). So they don't work for a sailing boat that usually travels at less than 8 knots, or any boat that spends most of it's time stationary (as ours do!). Commercial vessels, of course, spend most of their time moving at speeds well over 8 knots.
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Interesting, a shipping co. once explained to me that the demurrage charge associated with an idled ship reflect just the process you describe.

The future fuel costs of say a Handysize 30,000 DWT, or a Handymax 50,000 DWT ship are non-trivial, and dry-docking and a/f application costs eyewateringly (ok terrible pun!) expensive.

Edit: apols MissFitz for drifting this to vessels somewhat different to a Sonata!
 
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MissFitz said:
I've been advised by a very knowledgeable local racer to use black or dark blue antifoul rather than white because barnacles prefer white. Can anyone vouch for this? (My boat has bright orange topsides which would go better with a white hull - but it has also been annoyingly prone to barnacles this year, so I'm keen to discourage the little critters.)
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While we have learned a lot about barnacles and other undesirables, this thread has only approached the question of colour in terms of black and white. Whatever the merits or demerits of White, Black a/f seems to stay dark, but Dark Blue, when immersed for a time, generally fades to shade of Mediterranean Blue not unlike the chalk paints that are currently fashionable in interior decor. I thing this would look very well with bright orange topsides.
 
Norman_E said:
When I first needed to antifoul my boat I chose the Hempel paint that was recommended as working locally. In the Chandlery I told the owner that I wanted to change the colour so that I could see where I had painted, and suggested using white. He said I should not do that and put two tins, one white and one either black or dark blue, on the floor and asked me to pick them up. The white one was noticeably lighter. He told me that the white antifoul contained less copper and would not last as long.
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It's an interesting theory, but data sheets suggest otherwise! For International Micron Extra, the ingredients lists for black and white versions are identical, and the specific gravity of the white is actually a bit higher (1.95 vs 1.9).
 
pvb said:
It's an interesting theory, but data sheets suggest otherwise! For International Micron Extra, the ingredients lists for black and white versions are identical, and the specific gravity of the white is actually a bit higher (1.95 vs 1.9).
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The A/F in question was Hempel, and there was a definite difference in weight between the two full tins. I cannot now remember which Hempel version it was as I have had Coppercoat applied since, but the charter companies in Marmaris nearly all used the same one in black or dark blue because it worked OK locally and was readily available.
 
William_H said:
Thanks Tim O for the detail on barnacles. I thought I got barnacles on my hull but perhaps what I get are limpets. They are conical shells that are very firmly attached to the antifouling and yes when I smash them off they take the paint with them.
I got some yesterday while swimming under the boat and being less than a week old could be removed with a finger insulated with rag. However mostly even after 2 weeks I need a metal scraper to remove them.
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If you remove barnacles while swimming, wear earplugs. I had one of the little critters get into my ear and start eating my eardrum. Very painful, and I had a devil of a time getting it out of there. Ended up squirting WD40 via the red plastic tube into me ear - it's unpalatable to them.
 
dom said:
Edit: apols MissFitz for drifting this to vessels somewhat different to a Sonata!
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Please don't apologise, this thread has been great, had no idea that a simple question about barnacles could give rise to such a fascinating debate :)
 
Spirit (of Glenans) said:
While we have learned a lot about barnacles and other undesirables, this thread has only approached the question of colour in terms of black and white. Whatever the merits or demerits of White, Black a/f seems to stay dark, but Dark Blue, when immersed for a time, generally fades to shade of Mediterranean Blue not unlike the chalk paints that are currently fashionable in interior decor. I thing this would look very well with bright orange topsides.
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Not a bad idea at all. And dark blue antifoul would also have the advantage of going with the increasingly large patches of gelcoat showing through where the previous owner's rubbish paint job is rubbing off!
 
I think one of the problems with white antifoul is that the only white Cu containing pigment available is copper thiocyanate. All the other copper compounds are strongly coloured, a popular one for a/f being the red copper (I) oxide. So that gives the paint manufacturer less freedom in formulating white a/f.

However, I did talk with a Blakes rep (before it became Hempel) and he said that all the colours were as effective as each other. This was after I found that the white A/F used by the previous owner was not very effective in the relatively bad-for-fouling Chichester Harbour. I then used a darker colour in subsequent years, and I am sure it was more effective.

So I am sticking with the darker colours.
 
Last year's paint was dark grey, and fouling was noticeably worse on the side that saw the sun (river pontoon) and so I wondered if a lighter colour might not get quite as warm and so stay cleaner.

I've bought white, and am thoroughly disheartened to read that the fertiliser I seem to have used last year is now replaced by crustacean's nectar.
 
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