Diver applied underwater paint?

[MicHughV]

I routinely dive on my boat when I'm out cruising and anchored somewhere.
I do this mostly to scrape the prop clean and inspect the zincs, but while I'm down there, also give the bottom of the keel a quick scrape, as well as give the rest of the hull a quick looksee.
This typically takes care of all my underwater maintenance in 15 minutes or so.

[Chris Cringle]

I had a wooden boat while cruising the tropical Pacific, far from haul out facilities when I struck a mass of floating, abandoned fishing gear which scraped some anti fouling paint from my rudder. I was worried about toredos getting into my rudder so I mixed some bottom paint into some underwater setting putty and applied it to the bare spots. It worked for several months.

[JPA Cate]

Originally Posted by Chris Cringle

I had a wooden boat while cruising the tropical Pacific, far from haul out facilities when I struck a mass of floating, abandoned fishing gear which scraped some anti fouling paint from my rudder. I was worried about toredos getting into my rudder so I mixed some bottom paint into some underwater setting putty and applied it to the bare spots. It worked for several months.

Brilliant! A good creative fix.

Thanks for the idea.

Ann

[Don C L]

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

[fstbttms]

Originally Posted by JPA Cate

Brilliant! A good creative fix.

Not really. Anti fouling paint works by allowing water to penetrate its matrix, thereby allowing its biocide to be released. By encasing it in a waterproof epoxy (or whatever), you eliminate its anti fouling properties.

[s/v Jedi]

In many parts of the old world they have tide grids that allow access under the keel in between the grid beams.

The underside of my keel is lead and nothing really likes it so I don’t put much effort into it.

[Franziska]

So, we'll see.

I will get enough of that diver applicable paint delivered, they even offer it as a free testing sample.
So, I'll report back unbiased (!) here in a few months how it holds up.

In the best case it works reasonably good by itself, if that is not the case but it will make cleaning easier its still good. In the worst case it's just another layer of paint at the keel soles which does not harm.

Essentially we really have nothing to loose in this case and might safe on the lifting operation.

Thanks everyone for their contributions.

[Franziska]

Originally Posted by s/v Jedi

In many parts of the old world they have tide grids that allow access under the keel in between the grid beams.



The underside of my keel is lead and nothing really likes it so I don’t put much effort into it.

Ours is a cat, so will be unlikely to fit on a grid.
No lead transporting either.

Still I have applied the antifouling to all other parts of the hull already in a few tide cycles while dried out on a sand beach, which is a huge plus.

[Franziska]

Originally Posted by fstbttms

Not really. Anti fouling paint works by allowing water to penetrate its matrix, thereby allowing its biocide to be released. By encasing it in a waterproof epoxy (or whatever), you eliminate its anti fouling properties.

But the Toredos mentioned will not get to the wood. Which is a big plus. So it's a clever solution after all.
Might not stop creatures from attaching, but prevents severe damage.

[fstbttms]

Originally Posted by Franziska

But the Toredos mentioned will not get to the wood. Which is a big plus. So it's a clever solution after all.
Might not stop creatures from attaching, but prevents severe damage.

There is no reason to add anti fouling paint to the epoxy. It’s the epoxy that protects the wood from toredos, not the paint. The paint plays no part in it.

[Franziska]

Originally Posted by fstbttms

There is no reason to add anti fouling paint to the epoxy. It’s the epoxy that protects the wood from toredos, not the paint. The paint plays no part in it.

I never said differently. He used the epoxy to seal up his rudder. Which, by the sound of it had exposed wood.

[fstbttms]

Originally Posted by Franziska

I never said differently. He used the epoxy to seal up his rudder. Which, by the sound of it had exposed wood.

The “clever” part of the solution was adding anti fouling paint to the epoxy. Not sure what isn’t clear about that.

[boatman61]

Originally Posted by fstbttms

The “clever” part of the solution was adding anti fouling paint to the epoxy. Not sure what isn’t clear about that.

Colour match..

[double u]

years ago a friend of ours swore that underwater "application" of AF is possible & he had done it before.
So down I went with a brush full of AF to coat the soles of the keels on our cat - & ended up with droplets of AF in my hair as they came off when I "brushed the AF on". It stuck well - but only to my hair.
was in 83, so maybe advances in paint technology since then (& maybe not)

[Franziska]

Originally Posted by double u

years ago a friend of ours swore that underwater "application" of AF is possible & he had done it before.
So down I went with a brush full of AF to coat the soles of the keels on our cat - & ended up with droplets of AF in my hair as they came off when I "brushed the AF on". It stuck well - but only to my hair.
was in 83, so maybe advances in paint technology since then (& maybe not)

The company I am in contact with does actually produce a paint, which is applied by divers as corrosion protection coating to underwater structures.
I found quite a number of these underwater applicable coatings from different brands. They seem to be not that uncommon.

It's the antifouling properties which they say have been added which are the novelty.