Antifouling application

Hi All ,
I d like to ask you about the usage and application of anti-fouling paint.
We are about to launch our 62 feet motoryacht and this is time to apply the a.f. paint.But I am hesitating about the number of primer layers and a.f paint layers on the hull.I am planning to apply one layer of primer and 1 a.f paint.Would it be enough to use this much,or do I have to increase the a.f layer for the paint not to get peeled off when launched? Thanks

 

Hello Tumer,

not that I would know how to answer your question,
on my 30 foot marine ply boat, when restoring, I scraped everything flakey off (old antifoul unlike yours that sounds brand new), sanded, and primed two to three coats of international yacht primer (the grey stuff) on any raw or close to raw wood- then I applied a first coat of (ablative international coppercoat) antifoul on all of the high wear areas, the Bow, the chine, the waterline, the ruddder, etc, etc, and then two more coats on top of the whole thing (overkill I think). This was to 'set it right' for at least a year in the water.

For those that are equiped to do so, to better answer your question, you might want to provide a little more info.
What material is the hull, and has it had any treatment or paint?
what antifoul are you going to use, brand, and is it hard or ablative?
what primer?
Where, what and how will the boat be used, and when will it be hauled out and repainted next?
etc,

Good luck.
Hans.

 

Thanks Hans, my boat is made of GRP and it is brand new.We are a little bit hurrying to launch it since the Istanbul Boat show is approaching and we will exhibit it.According to the things that you said, I have to use more layers of both primer and antifouling.Does that really matter which brand it is ?It is not something common , a local brand I am using.

 

Hello Tumer,
I just told you what I did to my boat as an example.
I really have no idea what you should do on yours.
I am suprised someone else hasn't stepped in.

as far as getting advice here from the people who are equipped to give it (not me) I think that providing the brand, but more specifically the type of antifouling (hard or ablative) is quite important for you to get the right advice.
But also esential is the other questions, where, what and how will the boat be used, and very importantly, when will it be hauled out and repainted next.
If you are going to pull it out straight after the boat show (or relatively soon after), then possibly (but again I hesitate to give advice) one layer of antifoul might be ok, as you can give it another at this time.
As far as priming goes, I would give it a really good coat, as untill the day you strip it right back to the GRP, this is your only chance.

I am sortof assuming that because you have a 64 ft motorboat you know a bit about this already, but maybe, is this your first???

There are many different types of antifouling paint. On a boat this size, and price, you really need to do some serious research on what type of antifouling you want rather than just go with 'a common local brand'. This stuff could be good, but maybe not. Once you go one way, with one type or brand, often it will exclude you from changing to some of the others untill you strip all the old stuff off. On your boat, a very big and expensive job.

Good luck.
Maybe get yourself some local on the ground advice.
Maybe someone will step in and advise here.

Hans.

 

I used to work for International Paints. Sunseeker, Sealine, Princess were my customers.

What speed does boat expect to do? How many miles between lifting? Where you moored?

All key questions. Ask locals in marina. They will have favorites from experience - though even in one marina you can see wildly differing results (due to tidal flow, sunlight etc)

Even 'hard' antifouling polishes/sloughs off. If you zip at 50knots, it ain't same as 18. Likewise if you motor every week as opposed to 1x per month.

Make sure you degrease/dewax the gel before you do anything. Easiest/safest prep is sand gel with 150grit. 1 coat of primer is normally enough. It's just for key.

Not all af'are same - contrary to some beliefs. If you are selling boat, I'd put on known brand. The customer will have to overcoat. You don't want it all falling off in 2nd year and your local supplier blaming what was used on top.

You can easy apply 1coat for show then recoat - if you can afford time and money of this. Otherwise, I'd strongly recommend 2 coats for 1st application. If it did polish through back to primer, it is nightmare to get it prepped back and the primer will foul real bad, real quick -not best advert really.

Speak with all the suppliers. Most have help desks - I know International Turkey does. They'll spec out volumes for you. (good point to remind you - don't underapply. The thickness dictates performance. Spreading 5lt over 62foot will save you money on paint and lose you money on loss of speed/more fuel/divers. Apply it at recommended dft. If you've material over, you're not lucky, you've just put it on too thin. If you really want to skimp, apply 2 coats of high wear areas and leave the bottom with single coat)

 

Professional Boatbuilder has a good article in the latest issue online. http://www.proboat-digital.com/proboat/20070203/
Gary

 

The article was interesting. When I was International, we knew of this stuff/technology.

Not sure how well it works on the undersides ie where there is no sunlight to kick off peroxide generation(it suggests it also has another non-copper biocide, but copper is best at stopping animals as opposed to plants).

For Europe , it needs to be approved for environmental impact. You'll have to see if it available.

The real boys ie container/ferries = ships that motor for money still like stuff that kills and that means copper in the main. (or TBT if you are lucky enough to ignore IMO regulations (like USA for a while)).

Off topic slightly - it's best for environment/boat to lift it out of water at end of every day/trip. I saw some great sheds in Switzerland to do just this even for big boats (up to 18m if I remember). They just got lifted about 30cm out of water and sat in sling. The shed was even covered so your topsides didn't get faded! I'm sure it mustn't work out that much dearer in long run and you have no osmosis issues, no fouling - less fuel consumption.