maybe a stupid question - how many L antifoul for a fin keel 9.5m boat?

Cactus Sailing

Cactus Sailing

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just trying to budget vs the boat yard doing it, i know its not a pretty job but basically;

Anti-foul 5L + DIY overall and PPE inc decent face mask and tape etc is £140 + prob a days work

Boat yard want £316 for 1 coat

The hull is in good condition the keel is not perfectly smooth but im no racer so was just going to go over it, or should i be filling this and making it perfectly smooth, (we're talking 1-2mm differences here and there where the primer differs after getting rid of some rust), so im tempted to just DIY it following advice on how to apply from PBO article, seems straight forward and saves me £176? and 5L will get me 2 coats easy i would have thought?

i've just never done it before and dont want to overbuy / underbuy antifoul, if its more complicated than im thinking then do shout.
 
It's an easy DIY job. Best to start by washing the hull with a running hose and a nylon pan scourer, this will get rid of any loose antifoul, bits of fouling, etc. Apply blue masking tape round the waterline. Don't worry too much about the smoothness of the keel. Two coats by brush should use about 5 litres of antifoul. The effectiveness of the stuff depends on how much you put on - applying by brush gives a decent film thickness. Do a third coat around the waterline and on the leading edges. I use International Micron and it lasts two years continuously in the water, but it is £120 for a 2.5 litre tin, so considerably more expensive than the stuff you've priced up. My view of the economics is that using Micron is expensive, but gives me 2 full years in the water, so saves money on liftouts as well as reducing the time I spend antifouling.

Your boat yard will most likely apply by roller, and they'll use very little antifoul for one coat!
 
pvb said:
Your boat yard will most likely apply by roller, and they'll use very little antifoul for one coat!
Click to expand...

this is my findings from the yard which did the anti-fouling last year, its pretty much non-existent in places now, its the hempal cruiser - currently on offer , and what the yard put on last year IIRC (international cruiser is also scarce atm, micron is available but maybe ill stretch to that next year as its £120 a tin), any reason for blue masking tape? i was going to use frog-tape, most likely i will apply by roller to be honest for a flatter finish but will stick plenty of coats on, may as well use the 5L as long as its not overkill even if that means going over 3 times with the roller and 4 on the leading edges?

the only other thing is where the blocks touch the hull, i assume i give these bits a quick paint while in the slings?
 
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We use 3 litres every year applied by roller, hull only (not the keel), 10.6 metres. 5 litres will be comfortably enough.

Blue masking tape can be left on overnight and gives a better edge. Conventional stuff really needs to be taken off the same day but that is rarely a problem, two coats per day easy to achieve.
 
Do you have to lift the boat every year? If not, going for a 2-year cycle does save money, which is why I do it (apart from the fact that it halves the time spent antifouling!).

I always use blue masking tape as it usually comes off cleanly, even after a few days of sunshine exposure.
 
My 9m fin uses about 1.25l per coat and gets one coat a year (one tin "should do me 2 seasons) but we get very little fouling in the mud. If I was somewhere a bit more blue I would probably use the whole tin.
 
IMHO better one thin coat of the best available antifouling with a second thin coat 6" down from the waterline, and on leading edges of keel and rudder, than two full coats of cheap stuff. I use 2.5 litres of Shogun or Micron every year for a 10+ metre boat, in water March to Oct/Nov. Comes out pretty clean despite a high fouling area. One year I did one side with Shogun and the other with Micron, no difference on haulout, and Shogun is cheaper. I want to be out each winter, so the "put lots on for 2 years" is pointless.

Use as much as you like each year, but you'll regret it in a few years time when it has to come off as it's getting really thick and crusty...…

PS. To clean off a builders pole sander for drywall work with mesh abrasive and a hose taped to the pole is SO much easier and cleaner for the user than hand scrubbing.
 
Just done our 9.5m, used 2.5 litres with a drop left over in the tin, used small roller rather than brush
 
Frog tape, be careful it is designed for water based paint the advise is to wet the tape to seal it and avoid paint creep. I usually use the cheapo stuff and remove it immediately after painting and put more tape on if I do another coat

David MH
 
Thanks all, I asume if I have spare left over it won’t last in the tin until next year? I suppose Unopened it will be fine? (Just in case 5l is excessive as maybe 2.5l is enough)

I’ll take the tape off straight away I think, the boat on the hard next to me has masking tape welded to his Hull now and doesn’t look like he is having much fun to be honest!
 
We use cheap tape, Josephine puts it on as I get started. We aim for 2 coats by roller and aim to complete the 2 coats within one day and take the tape of at the end of the day. We doing not 'stretch' the paint out - more paint means longer life. We too get 2 years - we are in the water 365.

We have been using Jotun Quantum Extra or Hempel Globic - both are commercial AF, are difficult to buy in Europe and not cheap - but better than Micron, by a long way - at least here (Sydney, Oz) - I know - I tried them all, side by side.

If your anodes need replaced annually and you need to slip to replace or your prop needs an annual refreshing of AF then you may as well refresh the AF at the same time. If your anodes and prop can last longer then aiming for 2 years would be the ideal. We have tried lots of prop treatmernt and the best so far is Velox. Velox does not last as well as our chosen AF and we do need to wipe down, maybe, every 8 months.

Most modern AF, for hull or prop, depends on movement - if you leave your vessel unmoved for a couple of months, and maybe less in summer, then expect it to develop fouling (which can then only be removed by wiping down, sometimes aggressively,) no matter how much you pay for the paint nor the coating thickness.

I have noted in the past that many quote amazing results in Europe - but omit to mention they store on the hard for 6 months - no reference to anyone answering this thread - just be careful of claims from those who do not mention how they use their yacht.

Personally neither of us minds AFing - it takes a day every 2 years. We get to check all the hull fittings, we check the anodes (and usually replace). Its really not that hard and certainly requires little thought - you could train monkeys to do it (and certainly does not merit the costs that yards impose). And the transformation in looks, increase in hull speed subsequently and the knowledge it has, all, been done properly - makes it all worthwhile.

Jonathan
 
The amount and type of antifouling required depends on the severity of fouling in your area, the time in the water, and whether the boat is used, or sitting idle. We don't know your relevant circumstances. In my own case, the boat is used extensively, but only for six months in the "summer", then laid up ashore. Accordingly, we roll on a single coat of a copper-rich antifouling, and have no growth at all. Every winter it is rubbed down with a pole-mounted pad using abrasive gauze used with plenty of water. That has meant that after 12 years, there is no build up of old tired flaky antifouling.
Ah, yes, the original question, for our full bodied 36ft ketch, 2 litres is all we use.
 
NormanS said:
The amount and type of antifouling required depends on the severity of fouling in your area, the time in the water, and whether the boat is used, or sitting idle. We don't know your relevant circumstances. In my own case, the boat is used extensively, but only for six months in the "summer", then laid up ashore. Accordingly, we roll on a single coat of a copper-rich antifouling, and have no growth at all. Every winter it is rubbed down with a pole-mounted pad using abrasive gauze used with plenty of water. That has meant that after 12 years, there is no build up of old tired flaky antifouling.
Ah, yes, the original question, for our full bodied 36ft ketch, 2 litres is all we use.
Click to expand...

Yes, I should have included that the light 9 metre gets two generously rollered coats with a cupful left over from 2.5l. Still doesn't work though....
 
I don’t know how so many people can make their antifoul stretch so far.
Like the OP, our boat is a 9.5m LOA with a fin keel. It takes two 2.5 or 3L tins of Cruiser Uno to cover with one coat applied by a roller and any left-over paint is barely enough for a second coat above the saildrive, and at the water-line.
Once on, it has lasted 18 to 22months between applications, possibly it would go longer as it is still working when lifted out. My previous motor boat used one 3L tin of Uno for a 21 foot semi-displacement hull.
 
All antifouled now :)

ended up using approx 4.5L for 2 coats plus a 3rd on leading edges and water line, looks great now, not sure how i could have made it stretch further tbh, we will use the rest for the pad areas which are currently covered on the lift in.

the 1st coat we put on was over some primer patches so it was obvious when the roller wasn't covering it sufficiently, glad we did it ourselves though was very straight forward.
 
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