Antifoul

[wheels 543]

Arrr, right, that clears it a bit.

So first off, you have a reasonably fast hull. Don't worry about the average of 8kt, look at what you can actually achieve. Certainly at 19kts, any soft fouling will not stand up for long. But if 19kts is rare, then the softer types may still be your best bet. 10 to 12kts is OK, 15kts is upper range IMO.

Simplifying the coatings, for standard copper based anti-fouls, you have three types. Soft, medium and hard. Also called Erroding/self polishing, Ablative and hard.

Apart from the first few months, ALL antifouls foul up. You will never get anything that stays perfectly clean. No matter where the boat is. The type of fouling may vary, but you will always get something.

Soft and mediums are designed to clean when the boat moves. Hards need to be physically scrubbed. The Hards are designed for speed and racing boats use it not so much because of the speed they do, but that they can sand and polish the hull to a fast finish. But the hull needs to be cleaned every few months and some fanatics do it before every race.

Apart from the physical make up of the coating, There are two main operative components in Anti-foul. Copper and Biocide. The soft coatings are desinged to have a surface that is wearing away and exposing fresh amounts of both those additives. So for them to perform, you actually need a good thick coating to start with. On high turbulance areas, like leading edges etc, you need even thicker.

Yes it is expensive stuff and as a result, people tend to try and make it go as far as they can. But you always need to have a thought in your mind, "Apply it like you didn't pay for it". Rolling it on, you need a minimum of two coats. Preferably three. Spraying via high pressure airless can allow a heavy coating, but that is still only if applied heavy. Many don't do that. I get my hul sprayed and then I go over the high wearing area's with the roller and lay it on thick. Ofcourse, the thicker you apply, the longer it takes to dry properly and most people try applying and getting the boat back in the water far too quickly.

ALWAYS follow the instructions

Coppercoat.

Hmmm, well personally, I am not a fan. You have to regularly scrub the Hull and sand it every year. So why???? If I was spending that kind of money, I would be dissapointed. The only advantage I can see is being able to polish it to a nice shine and it is a nice colour. To give you an idea of how effective it is, I have hung pure copper sheet in the water and it still fouls up.

So.....if initial cost is not so much a problem and the result is that you could get a long time out of the anti-foul, I suggest you go talk to the Hempel guys about their Hempasil X3.

x3 is a Silicone-based fouling release coating that creates a smooth non-stick surface on the hull so fouling organisms can’t attach. A completely biocide-free product so does not leach any harmful chemicals into the marine environment. It is also a high solids paint which means it does not have a lot of solvent in it.

You need a bit of speed to allow the hull to clean, but it just falls off and a broom will clean it easily. You will get 10yrs from it.

[Guest]

Meg,I put two gallons ( one should give two coats) on with a roller, trouble is in the river silt is a problem so after a month or two I had to wipe her bum every two to three weeks (okay so i left it a little longer when the water got cold)

Trouble with ablative is when you wipe you loose a bit of antifoul and she sat on the bottom a few times according to JT.

 

Ultra or hard antifoul will best for beaching but all antifoul will slime up and if you don't wipe the bum the gremlins get a foot hold. Just buy the boy a wet suit and stand on the shore and issue instructions.

 

Sorry i sold you that pack off problems best I can do for you is take the whole lot back

 

If you can stop her sitting on the bottom I like Micron 66.

[wheels 543]

To clarify a little, Silt has no direct issue with the anti-foul. But the Silt can be full of nutrient which helps to speed up growth. The first thing to grow is algae. That is what we call slime. This acts as a barrier to the anti-foul and the life that then see's the algae as a lovely bed to grow in.

You will get different types of growth in different environments ofcourse. Fresh water coming down can be both an enemy and a friend. One thing that does tend to happen in these esturies and rivers is that a lot of nutrient washes off the land and that does help to cause the growth of sheelfish to be more rapid. But it also tends to knock back the plant life. Big flushes of fresh water will also stop shellfish growth, but you need to be in a fresh water river for that. Dirty water gets heated faster and so becomes somewhat warmer.

Dark anti-foul also gets dirty faster. Black is the worst because it absorbs so much heat. So the light blue is probably the best choice in colour.

When we give the bottom a brush to get rid of the slime, that coating that washes off would have washed off normally when underway anyway. That is how it works. The old depeleted layer comes away takeing the growth with it and exposing new toxins to reduce new growth.

An important point to understand is that NO COMPANY has a perfect anti-foul, as in some kind of coating that completely stops all growth, because of the current legal regulations of what poisons we are allowed to have leatch into of water. Those poisons are going to become more and more regulated, as we are seeing and so the future is going to be in completely different methods of keeping the bottom clean. Hence the developments in the slippery coatings like silicons and Teflons etc. Still, that has limitations also.

[Atom Ant 0]

I haven't read anything for a while but wasn't there some success with water based a/f's in the US of A?

 

Wheels, I am a bit confused as I remember going to an antifouling night (ok it was probably over 10 years ago) and the paint co guy - might have been Altex but not sure - said black a/f was the best as it had a higher copper content. The lighter the colour the less copper it had to enable having the lighter colour. I'm not trying to do a he's right so you must be wrong thing here, but I guess it gets confusing for punters when we read or hear completely contradictory things and have no clue what to make of it.

 

Having said that, and having had grey, white & black a/f of the same brand over the years, I couldn't tell you one was more or less effective than the other, but certainly growth showed up faster on the white, due to the colour difference between the paint and the snot that was forming on it. The benefit of white of course is that in due course you get a nice green water line mark due to the exposed copper.

 

I'll be putting on War Paint next time - because I won it in the last twilight series I raced the Ant in. I will be interested to see how it goes as I have never used it before but I understand I can expect similar performance to Sea Horse.

[wheels 543]

The lighter the colour the less copper it had to enable having the lighter colour.

Well no he is not quite right. Although I was about to say you can not get white in a copper based anti-foul till you just said you had it. I have no clue how they could produce it though. It is not copper as such that goes into the coating, but Copper oxide, which is greeny/blue'ish in colour as you would probably know. So hence the strange range of colours that tend to be available. The greeny/blue'ish colour dirties up the actual paint colour . White used to always be in the non copper based coatings. Like the ones for Ally Hulls and Boot toppings.

[rigger 47]

took less than 1min to find a white antifoul containg copper in the form Cuprous Thiocyanate

 

http://www.pettitpaint.com/fileshare/pr ... 116106.pdf

[Megwyn 2]

Cuprous Thiocyanate

 

 

Sounds like deadly stuff. Would that even be legal in NZ?

[rigger 47]

have a read http://www.epa.govt.nz/search-databases ... cision.pdf

 

copper thiocyanate

- CAS Number = 1111-67-7

- HSNO Approval code = HSR003115

[Megwyn 2]

There is some pretty nasty stuff that they have approved there on that list.

 

Like the sound of that Hempasil Wheels - will need to follow that up and see if it is available to us plebs as it says for professional use only. Keeping her out of the water for a few days will be the trick, but possibly manageable.

 

Thanks everyone.

M

[Steve Pope 243]

There is a product called Econea that is now being used by various paint companies, it is a new generation antifoulant. There was a comparison test done by a yachting mag over the last 2 or 3 years using it, interestingly a waterbased sample was clearly better that the same product using an oil based carrier. Some manufacturers are topping it up with a zinc additive to make it even better. Costly though!! The developer is a firm called Jannsen. (google)

[wheels 543]

Yeah it's been around for a couple of years now. I am not sure what they are alluding to with the name. It is far from non toxic. The full chemical name is 2-(p-chlorophenyl)-3-cyano-4-bromo-5-trifluoromethyl pyrrole (say that 5 x fast) and it is hardly cheap. Although apparently they don't have to use much to be effective.

 

Rigger, the cuprous thiocyanate is not actually so bad. In fact there is a chance you come into contact with it every day. It is used in some toothpastes to stop plaque growth on your teeth.

[Megwyn 2]

cyanide in very small doses messes with the Krebs cycle as it blocks the electron cascade. Essentially this means that the power generator of the cells is shut down.

 

We do have millions, but it does not take much cyanide to slow the whole thing down considerably.

 

Probably how it stops gremlins growing on the hull . . .

[rigger 47]

Rigger, the cuprous thiocyanate is not actually so bad. In fact there is a chance you come into contact with it every day. It is used in some toothpastes to stop plaque growth on your teeth.

 

Never said how bad / good it was, just posted the link for Megwyn

[Guest]

Megwyn - cyanides and thiocyanates are two completely different things.

 

Cyanides most commonly refer to salts of the anion CN−, many cyanides are highly toxic especially hydrogen cyanide, and affect cellular respiration and can be fatal.

 

Thiocyanate is the anion SCN−, and compounds containing the functional group SCN are called thiocyanates. This is what is being discussed in the antifoul. Although some are toxic, none do what you say. Symptoms of thiocyanate toxicity are tinnitus, altered mental status changes, nausea, and abdominal pain.

 

Cheers

[Steve Pope 243]

interesting option, may be available through one of the big boys, Altex perhaps ??

[Megwyn 2]

Megwyn - cyanides and thiocyanates are two completely different things.

 

Cyanides most commonly refer to salts of the anion CN−, many cyanides are highly toxic especially hydrogen cyanide, and affect cellular respiration and can be fatal.

 

Thiocyanate is the anion SCN−, and compounds containing the functional group SCN are called thiocyanates. This is what is being discussed in the antifoul. Although some are toxic, none do what you say. Symptoms of thiocyanate toxicity are tinnitus, altered mental status changes, nausea, and abdominal pain.

 

Cheers

 

 

Thanks for that anttay - I was about to prepare the tin hat again

Although altered mental status changes can be a bit of a worry . . .

[Guest]

 

 

Thanks for that anttay - I was about to prepare the tin hat again

Although altered mental status changes can be a bit of a worry . . .

 

My mental status alters with a few beers……..

[wheels 543]

Megwyn, I fogot to say, if you are in a fast moving tidle area, you may need a medium hard coating or you will find it wears away too fast.

[Guest]

Does anyone know if Petit Trinidad, soft ablating type,is any good in NZ waters?

[wheels 543]

Yes it is. Providing it is applied correctly and is best suited to your needs. But then, all of them are close to one another. Petite is supposed to have the highest copper content of all the anti-fouls.