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leuk

Silicon antifouling

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Oi

 

First post here, so before everything else: hello! Nice to be here. Hope you're well, reader.

 

Does anyone have an experience with silicon based antifouling, such as the one Hempel is selling? I'm planning to use that on a 12m aluminum hull, and so far I heard and read various reports, ranging from plain bad to exquisite. Is it really difficult to use? How is it holding up? Is it solid? Is it worth it?

 

Thanks!

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Aquacote had a silicone antifoul product, and they went bust. Should tell you what you need to know about the current state of the technology

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For it to work it requires high use and high speed something all silicon manufactures either ignore or grossly understate. Avoid like the plague.

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(Pet) pedantic rant: silicones are a group of polymers which contain the element silicon (plus oxygen to make the repeating unit). Silicon's main use is as the most widely used semiconductor.

Rant over.

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Thanks for the replies, all. Yes, I've read that it was the combined action of both silicone's coat and speed that prevented critters from making friend with the hull. 5kph seems to be accepted as a minimum. 

I just thought that it looked nice on paper: no biocide, solid, and a bit of performance enhancement overall. Has any of you had an actual experience with it, or is it just common sense?

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Personal experience on a 25 knot fast ferry that my company owned in Australia

- works very well with a boat that is in constant use. After 1+ year in use we hauled it, pressure washed light slime, and it was like new.

- because it was so smooth most of the time we saved a lot of fuel

- works very badly if boat sits for 2 or 3 weeks at a time

- we were using an International product (Interlsleed 780?) and 7 knots was a bare minimum requirement. I'd be slightly sceptical about 5 knots unless it is in writing without any disclaimers

- VERY difficult & costly to apply (2 under tie coats, very tight specs on air temp/humidity/drying time before overcoating). Basically the stuff doesn't want to stick on. It's like putting teflon on a frying pan. Well not really but it is tricky

- a bit of a pain but not impossible to repair if mechanically damaged by floating debris. You can't just get a brush and slap on more where it was peeled off. You have to cut away a square beyond damaged material, redo the primer/tie coat business and the topcoat.

- Lots of big ship owners (cruise ships/tankers/container ships) are using it because they do get a big fuel savings which is about 1/2 - 1/3 of their operating costs. 5% of that is significant if you are a typical cruise ship burning 40,000 TONS of fuel a year, a few % of that counts!

[ there is no such thing as 5 kph (knots per hour).  Knots = nautical miles/hour. Hours are built in ]

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+1

Looked into it for a wet sailed Etchells.

Pros 

It would last 5 years and growth would fall off with a wipe

 

Cons

Bloody expensive, nearly $2k Australian for a boat with 22ft waterline, plus prep cost!

Easily damaged and hard to put on

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Thanks for the insight, that's really helpful. So maybe not a good idea in my case, then. Too bad. I'm soft hearten, and could not bear the idea of hurting tiny things (micro organisms, gas budget...). The hull being in aluminum also made it look like a neat solution. I'll switch to a more conventional AF and maybe give it a try later.

2 hours ago, Zonker said:

[ there is no such thing as 5 kph (knots per hour).  Knots = nautical miles/hour. Hours are built in ]

I meant kilograms per heliosphere of course, which is a way to measure ...ummm ...stuff... erm

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Propspeed is a silicone-based antifoul, a bit of a pain to apply but no worse than some varnishes. 

( A DIY version isn't too hard to make - mix a methylated silicone sealant (one sold for water immersion) with epoxy thinner till you get a paint-like consistency and apply over an etch-primed surface.)

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6 hours ago, Zonker said:

[ there is no such thing as 5 kph (knots per hour).  Knots = nautical miles/hour. Hours are built in ]

Knots specify velocity, knots per hour specify acceleration, which is really only a consideration on foilers.

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Anyone use Eelsnot? I used it for the last two R2AK's and thought it worked fairly well. It's not fun to apply, but it's not very expensive and seemed to keep stuff from growing too fast and seemed to make it easier to clean the bottom, which I did every 2 or 3 weeks. The question is, does it make the boat faster as claimed? I don't know, but it does seem to fill in the micro pores and scratches in the bottom of my boat.

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On 11/24/2018 at 5:20 AM, Zonker said:

we were using an International product (Interlsleed 780?) and 7 knots was a bare minimum requirement. I'd be slightly sceptical about 5 knots unless it is in writing without any disclaimers

Zonk I reakon it's double figures and nearly constant use. Manufacturers selling it to the moored sailboat market (with speed/usuage a fraction of that) and some cases as a green alternative to biocide products should be made to drink the stuff.

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It's certainly greener but yeah, probably not full glorious green. The brand I was looking at (Hempel) is indeed claiming that there is no biocide, not that it's green. They are also rather honest regarding its use on sailboats, saying it's working fine as long as you clean the hull on regular basis, that you don't get the hull out of water for more than a month (it would then need to be re-applied), and that you don't plan to collide with anything hard and sharp -while claiming it's resistant and solid, go figure. So, pretty much what you guys (and gals?) are saying, only in a more marketing friendly fashion.

 

Seems like a good deal of troubles for results that may not worth it. Especially since I'd like to focus on getting comfortable with the boat in the first place. If there was a performance enhancement, I would not be able to appreciate it.

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