Can I spread putty under-water ?

[Dave-Fethiye]

After recently purchasing a 12m wooden boat which was on dry land, I have done some repairs and have just put it in the sea.

Th boat had been under the sun all summer ( I am in Turkey and its HOT ) so before putting it in I soaked the inside using a hose pipe for a couple of days so that the wood would expand and close up the gaps.

After putting in the sea the boat has been taking in water from the stern for two days without any sign of further closing up so yesterday I decided to find out where the problem was. I swam under the boat and watched air bubbles get sucked into the joint between the tramson and the keel.

I then scraped out the joint and jammed cotton string into the gap ( they call it caulking ) using the same technique that I used when replacing some planks but this time with mask and flippers on !

To finish the job I need to cover the cotton with putty and paint it. Will the putty stick if I spread it underwater (sea water) ?
Also can I paint antifouling underwater ?

David.

[senormechanico]

Although I've never had to use it, there is a product called Splash Zone underwater epoxy. There are probably others.

Sorry, I've never heard of underwater applicable bottom paint.

Steve B.

[Tropic Cat]

3M brand 4200 or 5200 cures better underwater than it does in air. Both are one part polyurethane products. The 4200 is sold as a caulk and the 5200 as a permanent adhesive. I just used the 4200 caulk to seal a through hull hole for a new zinc while the boat was in the water and taking on water from that hole. It sealed and cured perfectly

They are both readily available, cheap and they work

[Roy M]

I concur on Splash Zone epoxy putty by Z-Spar. It comes in two shallow cans, one ingredient is yellowish, the other blackish. Open both the can's lids, dip your hands in water (seawater is fine), then dip your hand into one can, scooping out a golfball sized portion, dip the other hand into the other can and extract about the same size glob. It's not exact, and doesn't have to be, it's VERY user-friendly. Mush the two parts together, continuing to wet your hands to keep the goop from sticking badly to your fingers, until you get a uniform color mass, kind of an olive drab, about the consistency of Play-Dough. Smoosh the stuff into cracks, or roll it into spaghetti, or simply pile it on top of things, on top or underwater, pressing it onto the substrate until it sticks well. Continue caressing, fondling and cavorting with the mix until it molds into the desired shape. It takes a couple hours to harden, so come back to it from time to time to remold or remind it of its future form. After it cures hard it can be filed, sanded, epoxied, or painted (though I wouldn't hold out any hope for underwater painting).

I use the stuff for creating fairings around transducers, I cover my rudder hardware and shaft strut with it to make streamlined shapes that are easy to clean underwater. I use it for cosmetic and structural fills, and carry it as one of my stalwarts in the damage repair kit. I especially like it for setting stantion bases and pulpits because the bases almost never match the deck camber. Simply place a ball of the mix under the base, temporarily bolt the base down, and with water, smooth the excess into a sculpted form that looks like it was planned that way. Later, sand and paint the base, then seal it as you would the deck itself.

If you have leftovers, play with it. You can make some fun stuff on your boat such as drip lips on topside throughhulls, great fillets, or even a sculpted figurehead (one of my future fantasies).

Just remember, when you're done, clean those fingernails diligently or you will not get invited to too many parties. It's something about reaching for the snacks with hands that look like they've been in some nasty stuff.

The note on the polyurethane sealants is possibly even better for your application, since it flexes. Spash Zone is very hard when cured and wouldn't be a successful in a planked, aging hull.

[Alan Wheeler]

Follow the advice above for sealants. But I doubt you are going to get Anti-foul on under water. Your best bet would be to find a beach you can dry out between tides on and do the job that way. Even applyign the putty or sealnat or what ever would be easier to do than with a snorkel.

[Tropic Cat]

I haven't heard of any paint that you can apply underwater. Is one actually made?

[Dave-Fethiye]

Thanks for the advice.

I will go and have a look for 3M brand 4200. I guess that being a polyurethane product it will flex with the wood. I do have some 2 part epoxy putty but as it cures hard, nI did think it would keep water tight.

What about normal glazing type putty - linseed oil putty - that they put on wooden boats after caulking with cotton ? What that cure if put on under water ?

Alan - we don't have any tide around this part of the Agean. Anyway its quite interesting working underwater, I tied my hammer and caulking tool and scissors to floatation bouys (coke bottles) with long string because the shore dives down very deep and I can not see the bottom. Of course I wouldn't want to do it often but for a small jobs it quite fun !

[fstbttms]

Originally Posted by senormechanico

Sorry, I've never heard of underwater applicable bottom paint.

Originally Posted by rickm505

I haven't heard of any paint that you can apply underwater. Is one actually made?

You can find the underwater-applicable anti fouling paint in any good chandlery, right next to the screen doors for submarines.

[Dave-Fethiye]

I just read somewhere that
a product called "Life Caulk" would be good - but I might not be able to get it here (Turkey)

As a 2nd choice "Interlux" hopefully I'll at least find that one.

Is normal linseed oil putty out of the question ?
I did the cotton caulking today - the water intake is down to a "seep" now.
Maybe I should just try the putty and find out ?

Any thoughts/ advice ?

[Tropic Cat]

Dave

Life caulk is a polysulfied. It will cure underwater but it will take two - three weeks to cure. 3M's 4200 will cure in 24-48 hours depending on how thick it is and you are correct, it will flex. I'd start with that..

I am impressed that you could swing a caulking mallet with any accuracy under water. It is an art on dry land, so congratulations on your success. The 4200 will work, but is not ideal as seam caulking. I would be very tempted to careen the boat for a day, and take a good look at that seam, as well as checking your keel bolts. You could coat the whole thing with Splash Zone, and it would never leak (if you could afford that much Splash Zone), but it still would not fix the problem. Only cover it up.
As for traditional seam compound, it will not dry under water. It can be hard to work with, but for a traditional boat, it is well worth the effort IMHO.
Either way, good luck.
On a side note, if you have not yet heard of it, I would highly recommend Farley Mowat's book "The Boat That Wouldn't Float".

[Dave-Fethiye]

And what about linseed oil putty - "normal" marine type putty
or glazing putty ? Anyone know if it cures underwater ?

[edboat]

One of the companies I rep for has an underwater epoxy. It was developed to repair cooling tunnels at power plants without shutting down the plant. I have used it and it works very well. There are a number of underwater epoxies on the market.

[Dave-Fethiye]

I bought a polyester putty with hardner today and used that.
It had the tendency to drift away in the water but once I pushed it into the gaps it seemed to stay put.

I think that it will cure ok. I will check it out tomorrow.

[Tropic Cat]

Polyester doesn't flex