single
New member
Roughly how many litres will i need for a 31ft long keel grp yacht, draws 4ft.Also is primer essential?
How much antifoul?
- Thread starter single
- Start date
Cloven
Active member
5l does 2 coats on my 32ft boat. Primer if using a different make of antifoul or not sure of previous coating.
sailorman
Well-known member
5l of Jotun does 2 coats on my 37`
what ever is left will get used nxt time
Primer not req unless as a barrier coat
what ever is left will get used nxt time
Primer not req unless as a barrier coat
single
New member
5 ltrs it is then and primer.Not cheap!
ghostlymoron
Well-known member
There's a quantity calculator on the International website. But 2.5l per coat for a 30+ footer sounds about right.
laika
Well-known member
If you know what was on before, there's an overcoating compatibility guide on the International site somewhere (and probably worth looking for similar if using another manufacturer's paint). The International guide covers compatibility with other manufacturers' antifoul, not just their own.
Here we go:
http://www.yachtpaint.com/LiteratureCentre/antifouling_compatibility_chart_aus_eng.pdf
Here we go:
http://www.yachtpaint.com/LiteratureCentre/antifouling_compatibility_chart_aus_eng.pdf
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Halo
Well-known member
Do you need 2 coats?
The tin says so but I have only put one coat on (Hempel Tiger Extra) for the last 3 years and each year the coating gets slightly thicker and so far I have had no barnies - just a bit of slime.
One tin costs a lot less than 2 !! (yes I am a tight Yorkshireman with short arms and deep pockets)
I would talk to others in your area to see what thier experience is before investing in 2 tins
The tin says so but I have only put one coat on (Hempel Tiger Extra) for the last 3 years and each year the coating gets slightly thicker and so far I have had no barnies - just a bit of slime.
One tin costs a lot less than 2 !! (yes I am a tight Yorkshireman with short arms and deep pockets)
I would talk to others in your area to see what thier experience is before investing in 2 tins
raven
Well-known member
The "default" barrier coat seems to be International Primocon which I find quite expensive for my taste at about £20 for 750ml.
This season I have bought Flag Multipurpose Metallic Primer http://www.toolstation.com/shop/Painting+Decorating/Antifouling+Paint/d150/sd3261 - at £28 for 2.5 litres and similar content to Primocon it looks like a good deal.
This season I have bought Flag Multipurpose Metallic Primer http://www.toolstation.com/shop/Painting+Decorating/Antifouling+Paint/d150/sd3261 - at £28 for 2.5 litres and similar content to Primocon it looks like a good deal.
Sandy
Well-known member
28 foot bildge keel
2.5l one coat of the cheapest stuff I can get.
2.5l one coat of the cheapest stuff I can get.
smth448
Member
I would make sure you use all the AF if you have 5l. I used to put two coats on by roller and the coating turned out to be too thin. When I complained to the manufacturer when my boat had to be scrubbed every week they said that I hadn;t put enough on. I managed to get two coats out of one 2.5l tin. So if you put the stuff on with a roller and you still have loads left, go round again. If you use a brush it should go on thicker so you would only need 2 coats.
It makes sense, the thicker the paint film, the more biocide you have, so the longer it lasts.
I sail in a high fouling area so we need loads of the stuff. I also try to be careful with the mid season scrubs now as the pressure washer takes off the paint even wth a hard AF.
It makes sense, the thicker the paint film, the more biocide you have, so the longer it lasts.
I sail in a high fouling area so we need loads of the stuff. I also try to be careful with the mid season scrubs now as the pressure washer takes off the paint even wth a hard AF.
Spi D
...
tidclacy
Active member
raven
Well-known member
Wow!
Thanks for that tidclacy.
Too late this season, but will definitely bookmark for future use.
Thanks for that tidclacy.
Too late this season, but will definitely bookmark for future use.
FishyInverness
New member
The reason most manufacturers state 2 coats are required is because of the difference in height between the high and low points on the surface to be painted - these are usually greater than a single coat of antifoul, so the first coat would "sink" into the valleys, leaving the peaks uncovered. Algae then attach to the unprotected peaks, and weed then builds on the algae, and animal growth starts to colonise on the weed - at this point the growths can start to form a bridge over the peaks and create full colonies, effectively over-riding the antifoul effect.
Halo
Well-known member
Thanks for that - very interesting.
In my case there are layers of antifoul below the new coat so I expect that is why I get away with 1 coat.
If I were painting on a barrier coat or new boat then I would put 2 coats on plus more on the leading and training edges as suggested by the manufacturers
FishyInverness
New member
No problem, sadly I can't take credit for that explanation - I was given it by one of the technical experts at our paint supplier, but I keep useful snippets like that to hand!
I suspect your theory on having previous coats still in place would explain why you can get away with 1 coat too..and also might explain some of the claimsyou sometimes hear that "this antifoul didn't work, i'm covered in weed"...
single
New member
Looks good. Whats wrong with commercial a/f for yachts such as SeaQuantum Ultra on their website.No price listed, so maybe thats why?
Just_sayin'
Well-known member
We have tried alternate years of one coat, then two coats and noticed absolutely no difference. Once there is fouling that's it. The antifouling stops working.
We do however go round the waterline three or four times as the sunny side of our boat soon grows a weedy fringe and even rubbing that off lightly takes a cloud of paint with it.
We do however go round the waterline three or four times as the sunny side of our boat soon grows a weedy fringe and even rubbing that off lightly takes a cloud of paint with it.
sailorman
Well-known member
my wl is clean after 12 months with Jotun the hull has slime as she hasnt moved for 5 weeks