Idle thought on (anti) fouling

[Twister_Ken]

The result of some cockpit time waiting for the tide was this question.

For most of us the average speed of water past our hulls over a season is probably point zero something of a knot, because weekends are not long enough, and holidays are miserly!

So the nasties that nibble the bottom of our boats have still water and plenty of time to get attached. Antifoulings are (presumably) formulated with that in mind. But for the eternal wanderer, always on the move, are antifoulings necessary (or are they different ones)? Do barnacles grow on you, or does slime stick, at 4 knots?

Plus, if you go from marina parking using an eroding antifouling, to a 30 or 40 day Atlantic crossing, will all the paint have eroded away by the time you reach the other side?

And in any case are mid-ocean nasties different from coastal ones and not so (or more) susceptible to antifouling toxins?

 

[jamesjermain]

Good questions Ken.

Nasties certainly do grow in the wide blue ocean - even barnacles and certainly weed. I suspect these pelagic beasties are different from our home grown ones but I don't know in what way.

The eroding type of antifouling will reduce faster but two generous coats on Sweet Lucy was still doing good service after a season which indluded a trip to the Azores and back as well as a couple of trips to the West Country - a couple of years ago.

My problem this year has been a general flaking off of antifouling - up to five years worth. I am wondering whether it may be because I have lifted her out of the water three times since March which may have lead to repeated drying and shrinking cycles.
It may also be down to pure mistreatment after several years of doing antifoulding trials with dozens of different products!

JJ

 

[Adrian_Morgan]

Probably.

 

[andrewhopkins]

wonder what the ferry companies use?

The redfunnel ferries stop for a very short time and run back an forth at good speed (especially the cats). Wonder how much growth they get and what they do about it.

actually, how do you lift one of those out of the water ? Dry dock once a season ?

 

[vyv_cox]

When we kept our various boats on a mooring on the Menai Straits there was a period of no more than an hour or so per day when the tide was slack. The nature of the tides here means that flow reverses quite quickly, up to three knots in each direction on springs and not a great lot less on neaps. Despite that, the Straits is on International's list of high fouling areas and I can confirm that no antifouling I used post-TBT was ever effective

 

[jamesjermain]

Re: wonder what the ferry companies use?

They use TBT which is, of course, banned for use on yachts. They probably scatter as much of that across the Channel in one trip as all the Solent yachts would do in a season.

JJ

 

[Guest]

Interesting that you haven't found an effective anti-fouling. We're using Micron Optima now for the second season and so far it's been absolutely excellent. No growth last year (May - January), and I don't believe there has been any so far this year - the bottom of the boat still looks like it's a nice blue colour. Nor have we had to scrub or haul out except to reapply it in the Spring.

Have you tried it? It's relatively expensive but does save hauling out/scrubbing fees, so may work out cheaper in the end.

 

[billmacfarlane]

I had a problem with anti fouling peeling off. The port side of the boar faced south on her mooring and it was this side that flaked off. The starboard side remained secure. Weird or what ?

 

[Guest]

Just a suggestion!

I must admit to never having tried it Bill, but why do you need to antifoul a Boar???

 

[longjohnsilver]

I have a mooring on the Exe and have similar conditions to those which Vyv describes and can confirm that the boat gets fouled just as much if not more than when I was in Exmouth docks (about 400 metres away). However not a great problem for me as I dive and regularly scrub off the hull - much cheaper and easier than hauling out. My boat is 32' and the whole hull takes me approx 30 minutes. It is so much easier to clean it in the water, if it is left till we haul out and try the same cleaning methods it takes hours!

 

[chippie]

A friend is planning to put tetracycline antibiotic in his antifouling paint after reading that some americans have had success with it.
He says he will get it from the local vets who should have some that is past its use by date.;~)

 

[Guest]

It does seem to be true that if you keep moving the you get less fouling.

After our Atlantic crossing we had big goose barnacles all over the hull. Because of the antifouling, all we could do was scrape them off and throw them away. What a waste, when you consider what an expensive delicacy they are in Spain!

 

[LadyInBed]

Decided not to A/F . . .

I beached my boat in April for a scrub after it had been used for a year and kept on the River Frome (Wareham) for a year. It had built up some slime over the hull which scrubbed off easily, and some weed around the waterline which was a B... to get off. I decided not to A/F the whole hull, I just did around the waterline. I beached her out again on the equinox spring in September and was pleased to see no difference from April, so this time I've Just used a foot band of 'Boot Top' and raised it about 3 inches above the waterline, to cope with the weed. The boat is staying in this winter as well, and I am saving a fortune in A/F as well as (hopefully) doing a bit for the environment!

 

[Mirelle]

No longer so

Merchant ships were allowed to use TBT for much longer than yachts, because their speeds meant that a much harder composition was used, and most of it, in theory, went into the deep oceans (where, mistakenly, it was thought to do less damage). However, that is all in the past because the horrid stuff is now COMPLETELY banned, and indeed most responsible owners had discontinued it some time ago.

Most merchant ships are built to dry dock once every five years, now.