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antifouling quandry


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I neded your collective wisdom on my antifouling problem. I have 1/2 of a 4 litre can of grey Seahorse antifouling left. Apparently they're gonna stop making it soon and Burnsco don't stock it anymore. Question: What can I buy that can be used with what I already have? What sort of "used with" can I do? Mix it, paint over it, paint it over seahorse etc. Does anyone have a contact for buying it (whatever "it" happens to be) for less than the outrageous retail prices being asked?

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HeHe Wheels you're such a kidder! I use 6 litres at a time! Twice round the hull and a 3rd coat on the waterline and leading edges.

 

Benjamin Moore were most upset to hear that they are going to stop making it - it was news to them!

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Hehe, what you need is darn near the dreggs left in the 20ltr pale when they finish spraying on mine.

Anyway, pop around to Hempels. They have a very good soft anti-foul at a good price and I got a feelng (although could be wrong), that they have it in 5ltr not 4. So you might get away with one can instead of buying two and having to a half for the year. Any soft should go over another Soft just fine. They are all very similar, it's just the copper content and Biocide content that tends to make the difference and of course the price difference.

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for less than the outrageous retail prices being asked?

 

When the retailers sell a $300 tin of paint and make, going well, $20 on it I think you'll find it isn't the outrageous 'retail' price that is the problem.

 

You need to speak to a guru I think AA. Some anti-fouls don't go over other anti-fouls at all well.

 

Strange as it may seem I had a chat with STS (yes that STS) about paint issues inc anti-fouling and he was a mine of bloody good handy information. Maybe MS has a email for him?

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It's the hard foulings that become the difficult ones to match. Soft foulings, copper based eroding that is, have bascially the same resin binder. There are some exotic ones on the market, but are all commercial at the mo and damn expensive and can last up to 10yrs, but not available to the general public.

Soft foulings are very compatible with each other. They are not a "paint" as we know it. As long as the old surface has had a really good water blast so it is clean, a new coat of anything will go over what has been below.

Interestingly, for copper based foulings, there is actually no difference between much of the chemistry of soft, semisoft and hard. The difference is in the Resin Binder.

Hard being a binder that does not wear away and requires manual "polishing" to expose fresh copper and biocide. Because it's surface does no erode, it will slowly foul as the Copper/BC releases and becomes weaker till the next "polish".

Semi-softs are the erroding types that will foul when the boat is stationary for some time and when you get underway, will self clean. It is sometimes hard to know which an Erroding and Self-Polishing actually is. They are so similar and can actually be more a marketing term between companies.

Having said that,

Erroding types are ones that the surface is very soft and will wear even with the gentle tide running past and certainly will self clean once under way.

The main difference between these two soft type coatings is in where you boat is moored. In high tide speed areas, the tide adds up to being "Sea miles" and will wear away the really soft coatings quickly. You still want a wearing coating, but you need one just that slightly harder to reduce the fast wear. In a marina for instance, the tidal flow may be very slow and so a very soft coating is required.

The entire idea is that your coating should last the time between hauls. If you have too much left by the time of your next haul, then you are allowing too much of a build up over time and wasting money by not getting the total use of the coating. By having too much wear away, then you wast money by using excess fuel and slow sailing becasue you AF is no longer doing the job.

The Biocides are usually a Zinc based compound.

There are now some Teflon and Silicon based products available. But these are in a Hard only type so far. And commercial and very very epxensive. They do not have copper and rely on movement of the vessel to keep clean. And require a fairly fast hull. Suitable to shipping and higher speed craft. These types of surfaces as you can imagine, are difficult to recoat once they have had the product applied.

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I got stuck into ours a couple of months ago (originally intending to take it back far enough to switch to Micron 66, which I didn't quite have the grunt to do).

 

Anyway, if your boat has a history of only having a waterblast or quick scuff between antifouls, you may be surprised how much old paint you are hauling round the race track.

 

I reckon I took off four layers and there are at least three left (I can tell by the different colours). When you consider that each layer is probably at least one tin of antifoul, and I just put another two tins on top of that...it could be influential if you are, for example, trying to hold off a certain lizard-type creature in light airs.

 

I was introduced to this concept by someone on this site who is also full-time in the paint trade but I will let him step forward.

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Hehe, it could be increasing your waterline Length though :wink:

I think it is very easy for many yards to give a quick water blast. Especially the ones that are doing it as supposedly "Free" or part of the haulout cost. I like to blast myself and give a good hard clean. The heavier the old AF build up becomes, the more chance of uneven surfaces if a piece does fall away from the original undercoat. The second issue is that then at sometime, the yard can happily talk you into a Bum scrape and they are not cheap. So try and remove as much as you can each haul out. Hard AF's are a different story though. A proper removal and recoat is all part and parcel to obtaining that speed around the course.

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I used to just use wet and dry sandpaper to clean it for the last few times before a paint was due. Pull it out, give it a wipe and start painting.

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Cheers guys for the help. Seahorse is a semi ablative and although it has one of the lowest copper solid counts, it has been the best antifouling I have used so far. There is literally no AF build up as when the boat was last hauled, I took it back almost to the glass and put on 5 coats on interprotect and then the AF. It's back down to the interprotect in a few areas so it's due now and I've had my moneys worth so to speak. I generally don't like build up to occur so typically I'll sand it back without getting to the primer.

 

So Wheels, this Hempels stuff. Does it leave a nice smooth finish? Before you answer "it depends how you apply it" I guess that you need to know how I intend to apply it. Which is with smooth foam rollers. The ones that fall apart when used with AF paint but get around the boat once before doing so!

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Depends on what you call smooth. Softs and semis are both what is called "thixotropic". They have an almost "stipple" effect. Paint that you would use on tops sides is different. It has a flowing and self leveling agent added. AF's are very basic. They have the active ingredient/s held in suspension (after you stir it) by the thick Resin compound. The Solvent is there to enable you to get the coating from the tin to the Hull. After that it's job is done and you want it gone as quickly as possible. That is why some real nasty solvents are used, because the evaporation is the highest possible. They don't care about a Gloss finish, so solvent evaporation speed being the fastest is the required goal. You will note that Gloss finishes usually are the slowest at drying. Long list of reason, that's another discussion. The Solvent is there to hold the Binder molecules apart from one another. Once the Solvent is gone, the binder comes together and starts it's process of hardening.

How smooth will it be?? well yeah it does come down to application. But the Hemple range is no worse than any other on the market. Better?? can not say. Variables like Humidity and Temp play a big part in drying time also and drying time has a bearing on surface finish.

And in saying all that, i have achieved a better finish rolling than the guy gets with high pressure spray application. It's just too damn hard and slow for me to roll a hull that big now. However, i can truely say that Hemples is one hell of a good product, right up there quality goes, but I am only suggesting it because of the price to performance ratio.

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I think he means smooth as in a fast Reptiles bum type :thumbup: Which is vastly improved from it's 40 grit like finish but still needs a small tickle up.

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Use the existing 2l to paint your keel, bulb and rudder. Then use your new product of choice to paint the hull. That way you don't have to worry about mixing the two.

 

Also, when you buy your foam rollers, get oil based ones and they won't fall appart.

 

That reminds me, mine is due to be done as well.

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Cheers Wheels, I've read your email and I'm impressed! You know so much stuff! It's good to know people like you cos I'm more like the guy in the McDonalds ad. My head is full now so I can't remember any more than I already know without throwing something out first. But if I have to remember is "ask Wheels" then I'm set!

 

So what I have learned from you is that it works as well as anything else you're tried, it goes on as well as anything else you've tried, and it's priced competitively. Sounds like my kind of paint! And lets face it, what's the worst that can happen?... :wtf:

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Cheers again all the hints are good. Like the hint which means I won't have to mix paints which reduces risk. Good one CCG! Wheels I bet you nearly sh*t yourself when that happens. Hittin the bottom is nasty enough when its only a mud bank just off Devonport ( not that I'd know what that's like Honest!) But rocks at 7 knots just sounds downright scary! Your boat must be bloody solid!

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Cheers folks this has been excellent and all promulgated by a bit of incorrect information from a chandlery that said that manufacture of Seahorse was going to stop. That particular chandlery has stopped stocking it but Benjamin Moore assured me that they're going to continue to make it. But at $99 a can - that is a good price! That must have only just listed so thanks for spotting that TM! Now what colour...

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