Silicone antifouling

[Stemar]

Originally Posted by Stemar
Given the proven (in)effectiveness of currently available antifouls, I've often wondered about the possibilities of silicone wax on the hull itself. Has anyone tried it?

Theoretically, it should make the hull slippery enough that fouling can't get a grip and anything that manages to attach itself shouldn't be able to hang on under way, even at the low speeds of a ragtop



You're on the right track, but I imagine in the future it will be along the lines of laser etched superhydrophobic surfaces.
It's interesting, start a thread on the subject?

So here it is. Any thoughts anyone?

 

[pvb]

Hempel's Silic One has been around for about 5 years, long enough to give some feedback on its effectiveness. From what I've read, it needs frequent runs at a speed of 8+knots to keep the hull clean, so it's best suited to mobos and racing yachts, rather than the average cruising boat.

 

[Neeves]

One of the down sides is that if you try it and for whatever reason you don't like it - its a devil to remove to produce a clean surface allowing you to return to conventional AF. Another issue is the coating is soft and not abrasion resistant. Slings might damage the coating - or you simply hit a bit of wood as you sail - any nicks in the coating allow fouling to develop (this is one of the problems with Prop Speed).

Most of the major AF companies have a silicone treatment for commercial vessels (which have mixed success) and Intenational did conduct trials, on a racing yacht (I think in Holland), there has been no fanfare and I assume the trials did not meet expectation - or we would have heard more.

BUT - its (AF) a significant issue for commercial vessels - I'd expect there to be developments and my anecdotal comments may already be dated.

Jonathan

 

[Stemar]

Hempel's Silic One has been around for about 5 years, long enough to give some feedback on its effectiveness. From what I've read, it needs frequent runs at a speed of 8+knots to keep the hull clean, so it's best suited to mobos and racing yachts, rather than the average cruising boat.

OK, probably not ideal for a Snapdragon 24 then. On my handicap, I reckon that if I get round before the 2230 cutoff, I've probably won the Round the Island

 

[zoidberg]

I reckon if you can get your 24-footer up to a hull 'speed of 8+ knots' it'll need to clean your nappie as well as your Snappie....

 

[SvenH]

My prime worry is that after applying silicone you will never, ever be able to apply any other paint.

As far as I know silicone can not be removed completely, no matter what technique you use.

 

[johnalison]

My prime worry is that after applying silicone you will never, ever be able to apply any other paint.

As far as I know silicone can not be removed completely, no matter what technique you use.

I don't know how true that is; I have heard of people successfully painting after removing silicone polish. In the case of SilicOne, it is applied over three undercoats consisting of an undercoat and a tie coat, so the only problem would be removing the undercoat. I have used it on my prop this year. The results are not very promising, but I won't know until I lift out because the bottom is pretty foul anyway.

 

[Stemar]

I reckon if you can get your 24-footer up to a hull 'speed of 8+ knots' it'll need to clean your nappie as well as your Snappie....

Actually, with 28hp under the bonnet (long story) I can do 7 knots, but I lay a wake like a tsunami and burn fuel like it's going out of style, so I only do it as an Italian tuneup once or twice a year because the engine isn't usually worked hard enough to stay healthy.

I saw 11 knots on the GPS once, coming in through Hurst with a big spring tide pushing me.

 

[CAPTAIN FANTASTIC]

..... so I only do it as an Italian tuneup once or twice a year because the engine isn't usually worked hard enough to stay healthy.

I know that this thread is about antifouling but I am questioning this "Italian tuneup", especially for a diesel engine; there is no need. I am also aware that there are people who think otherwise.

In regard to silicone based antifouling, I would like to see how it develops in future because everything else seems to have less and less effect.

 

[Stemar]

I know that this thread is about antifouling but I am questioning this "Italian tuneup", especially for a diesel engine; there is no need. I am also aware that there are people who think otherwise.

In regard to silicone based antifouling, I would like to see how it develops in future because everything else seems to have less and less effect.

The reason my engine needs it once in a while is because it's a 28Hp engine in a 24ft sailing boat. The original engine was 8HP, but it died and the 28HP was offered to me for free; if I'd been buying, I'd have been looking for 16-18HP.

Under normal circumstances, it doesn't get worked hard enough, so it gets smoky. A flat out blast for a few minutes lays a smokescreen worthy of a destroyer on the Murmansk run at first, then it clears and and it's smoke free again.

 

[Spirit (of Glenans)]

I know that this thread is about antifouling but I am questioning this "Italian tuneup", especially for a diesel engine; there is no need. I am also aware that there are people who think otherwise.

In regard to silicone based antifouling, I would like to see how it develops in future because everything else seems to have less and less effect.

Certainly seems to work for my old Santa Fe (pre- Adblue etc) that I use for work; driving gently to improve the M.P.G. eventually causes it to become quite sluggish for the first mile or so when cold, The cure is to take it out on the motorway and go for about five miles as fast as I dare, in third gear!

 

[Trundlebug]

Yep

Italian tune-up is definitely a worthy thing in the right circumstances as described above.

The fact is, diesel engines need to work, preferably hard.
If they are worked hard as part of normal use (eg in trawlers, commercial boats, planing MB's at sea etc) no Italian tune-up is necessary because they get it as part of normal use.

But in applications where a diesel engine, or even a petrol is usually very lightly loaded, and / or on short trips, they slowly coke up and you can really tell.
So a good hard slog for long enough to get them properly hot and loaded hard will clear them out nicely; they run smoother, cleaner and more efficiently.

Tis a fact, well known by many including Ferrari garages, and it costs nothing other than the temporary increase in fuel consumption.
But it does engines the world of good to work hard.

(With apologies to the OP for the thread drift)

 

[vyv_cox]

I know that this thread is about antifouling but I am questioning this "Italian tuneup", especially for a diesel engine; there is no need. I am also aware that there are people who think otherwise.

Yanmar disagree with you. They specifically recommend it. I disagree also, as I use it on occasion. I was first advised to do it by a boatyard, who regularly motored boats hard for half an hour or so, to the delight of (absent) owners who were more than happy to pay £100 for the clear benefit in engine performance.

 

[Hot Property]

Back to the thread....

I have applied Silic One to my 7 m sports boat and will be reporting on its effectiveness (or not) as I pull the boat out in the spring. The sides of the boat do become a bit slimy but a rag washes everything off. I have been impressed with it so far and next time I will paint the bottom of the outboard bracket as its like a forest currently.... It won't suit everyone but for boats that can do 20+ knots as a minimum I think it will find a growing customer base as traditional AF becomes more expensive to apply (professional application only) and less effective when it is used. Stay tuned..

 

[tudorsailor]

Yanmar disagree with you. They specifically recommend it. I disagree also, as I use it on occasion. I was first advised to do it by a boatyard, who regularly motored boats hard for half an hour or so, to the delight of (absent) owners who were more than happy to pay £100 for the clear benefit in engine performance.

How often and for how long do you run the engine hard? How long is long enough? Ought I to see the engine temperature rise to indicate I am running hard enough? I have a Yanmar 4JH3-HTE

Thanks

TS

 

[vyv_cox]

How often and for how long do you run the engine hard? How long is long enough? Ought I to see the engine temperature rise to indicate I am running hard enough? I have a Yanmar 4JH3-HTE

Thanks

TS

This is an extract from the Yanmar operating manual:
'Operation, section 3. Paragraphs 7 and 8.

(7) When operating the engine at low speed for long periods of time race the engine once every 2 hours.

With the clutch in neutral accelerate from the low speed position to the high speed position and repeat this process about 5 times. This is done to clean out carbon from the cylinders and the fuel injection valve. Neglecting to race the engine will result in poor exhaust colour and reduce engine performance.

(8) If possible, periodically operate the engine at near maximum rpm while underway. This will generate higher exhaust temperatures, which will help clean out hard carbon deposits, maintaining engine performance and prolonging the life of the engine.'

I have never carried out instruction (7) because I do not operate the engine for long periods at low revs. Instruction (8) is the classic Italian tune-up. The boatyard who advised the method used to motor hard to the end of Holyhead breakwater and back, about 2 miles ~ 20 minutes. That's about the time I usually take. On first running at maximum revs the engine smokes but this clears after 5 - 10 minutes. Does make a noticeable difference to engine smooth operation but takes a bit of nerve the first time.

 

[CJU]

Many years ago there was an article in PBO about thin copper tiles that you stuck on the hull as a way of copper coating it. I have never seen any reference to it since, does anyone know if it was a failure or did it just not sell well enough at the time to make it viable to carry on manufacturing.

 

[vyv_cox]

Many years ago there was an article in PBO about thin copper tiles that you stuck on the hull as a way of copper coating it. I have never seen any reference to it since, does anyone know if it was a failure or did it just not sell well enough at the time to make it viable to carry on manufacturing.

They didn't work. Dick Durham's Contessa 32 was treated with them. I recall his article, written just after lift-out, quite well. His boat was heavily fouled, particularly at the edges of the tiles. He said that another boat lifted at the time had been antifouled with emulsion paint and had less fouling than his.

 

[CJU]

Thanks. That would be why I never saw it mentioned again. I often thought it would be an ideal solution, sort of like CC but without the epoxy binding.

 

[Stemar]

If you're really feeling extravagant, someone built a yacht out of cupronickel. She is or was called Pretty Penny, but the only reference that came up in a quick google was this.

It also talks about a boat built of CN but having aluminium bulkheads, and another with steel framing. Not sure I fancy that, I reckon the steel and ally could fizz away quite nicely