Diver applied underwater paint?

[Franziska]

Hi,

we recently applied new antifouling while beached.
The soles of the keels where naturally not accessible though.
Hauling just for treating these areas is not viable.

I'm wondering if anyone knows of a paint which can be applied underwater which has some antifouling properties.
Pretty sure something like this exists as there are structures out there which can not be hauled and need to stay reasonably clean.
I found some diver applied coatings and wrote to their manufacturers, but those I found had no antifouling properties as far as I can see.

Of course I will give the areas to be treated a thorough underwater clean before application.
Base substrate is epoxy with a bit of old antifouling on it.

Thanks for suggestions and suitable suppliers. We are currently in Portugal.

[Chotu]

Very interesting topic. Definitely following to see the answers. Hopefully you don’t get crucified like I did when I talked about drying out to just scrape off some growth.

As I am finally getting away from the equator far enough, I’m starting to see some good spots to do this. So I will be very interested to see if there is something for that bottom that no one can reach.

[Fore and Aft]

Franziska I thought most cats just used ordinary antifoul and applied it while sailing like this! If you look closely you can see the crew mixing the paint and one guys holding a roller with an extension handle.
Cheers

[Franziska]

Originally Posted by Chotu

Very interesting topic. Definitely following to see the answers. Hopefully you don’t get crucified like I did when I talked about drying out to just scrape off some growth.

As I am finally getting away from the equator far enough, I’m starting to see some good spots to do this. So I will be very interested to see if there is something for that bottom that no one can reach.

To late to crucify me , underwater is done.

I was dried out on a beach, but as I had put antifouling on last year and had not scraped it since then there was only mild growth on it which I removed while barely afloat.
No Barnacles, but then that is less of a surprise because the European Atlantic coast has cold water in winter and cool water in summer.

Still, as we are heading to the Med next I wanted to apply some additional coats because there is notoriously bad fouling in the Mediterranean.

Regarding the paint in this thread, I am talking to a company which is about to market something suitable. When I have their material in my hands I'll post more details.

[Franziska]

Originally Posted by Fore and Aft

Franziska I thought most cats just used ordinary antifoul and applied it while sailing like this! If you look closely you can see the crew mixing the paint and one guys holding a roller with an extension handle.
Cheers

Yes, way to go. Love it!

But as far as I remember they had a little mishap a short while later. Still a cool boat. Unfortunately my trusty cat will never be that fast. But we have a second hand kite now, so we'll see

[neilpride]

With tie and suit.

[Franziska]

Originally Posted by Franziska

Yes, way to go. Love it!

But as far as I remember they had a little mishap a short while later. Still a cool boat. Unfortunately my trusty cat will never be that fast. But we have a second hand kite now, so we'll see

https://m.youtube.com/watch?v=3YQCXeWhA-8

Just when that last piece of paint got finished. They could have used normal antifouling then..

[Chotu]

Originally Posted by Franziska

Just when that last piece of paint got finished. They could have used normal antifouling then..

This is the preferred way that we like to do bottom paint on performance Catamarans Ha ha ha.

You just capsize as you would normally do, then you take a minute to take out the paint brushes and rollers.

Saves a lot of time. You don’t have to wait for the tide or look for places that dry out.

[MicHughV]

The key to keeping the bottom of your keel clean from barnacles is to run the boat aground from time to time.
Be sure to have some good speed on the boat before attempring this.

[Franziska]

Originally Posted by MicHughV

The key to keeping the bottom of your keel clean from barnacles is to run the boat aground from time to time.
Be sure to have some good speed on the boat before attempring this.

Lol I was on&off a beach the last two weeks. Unfortunately it did not take everything off. Admitingly I was not beach at speed

[Viking Sailor]

Have you considered placing 4 wooden blocks under the keels. Thus, raising the boat high enough to clean and paint most of the bottom in one pass. Then on a following tide reposition the blocks to do what you didn't get done the first time.

[Franziska]

Originally Posted by Viking Sailor

Have you considered placing 4 wooden blocks under the keels. Thus, raising the boat high enough to clean and paint most of the bottom in one pass. Then on a following tide reposition the blocks to do what you didn't get done the first time.

I have, but getting the blocks and disposing off them later is a challenge without vehicle.
The have to carry over 4 metric tons and need to be large enough not to sink in.
I still could not paint our pivoting centerboard that way either.
I did think about digging a hole for it, but, that fills up with water and would need to be quite deep.

Talking to a paint company currently...

[rslifkin]

Originally Posted by Viking Sailor

Have you considered placing 4 wooden blocks under the keels. Thus, raising the boat high enough to clean and paint most of the bottom in one pass. Then on a following tide reposition the blocks to do what you didn't get done the first time.

That's what I was thinking. Given enough tide range, have the boat settle onto something so you can access more of the bottom.

[neilpride]

Opción A,B and C.


I have never seen an antifouling paint applied underwater, let us know when you hear back.

The other possibility is if your antifouling on the keels is ok, is to dive and clean from time to time.

[Franziska]

Originally Posted by neilpride

Opción A,B and C.





I have never seen an antifouling paint applied underwater, let us know when you hear back.



The other possibility is if your antifouling on the keels is ok, is to dive and clean from time to time.

Thanks, I'm aware of these more or less standart options, but they all involve reasonably big pockets, which is not viable for the small areas remaining untreated.

If we get this material delivered I will see how it performs.
There are actually a number of epoxy paints on the market which can and are diver applied.
Mind you primarily for corrosion protection. The one I am looking into mentioned specifically growth reduction.

Will see, if it doesn't work we just dive from to time, not such a big deal. Still I feel the coating suggested is worth a try.