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[surabaya]

Hi all,
I need help. I took my 50" motor cruiser out on the river for the first time and she looked great :), people passing made all the right comments , I felt proud of it until after about 10 mins, when I brought her back to check. Then happiness turned sour. :'(
  My hull seems to be leaking , but how to seal it. :-\
I have restored an old cruiser and thought I had done a fair job. Sanded, sealed, primed, painted and lacquered, but although it looks nice and smooth, it seems to be letting in water through the panels. I have looked closely and cannot see any holes or cracks,but still it leaks through the panels. It is almost like the wood is porous and it seeps in.
 The inside of the hull was paint previously and even running some waterproof PVA along the joints does not stop it.
What can I do without completely redoing the out side of the hull.

[Shipmate60]

surabaya,
First try and identify where the water is entering.
Check the propshaft first, if it isn't that.
Dry out the inside even using a hairdryer then put the hull in the bath and watch it.
if no leak apparent put her in the normal sailing attitude and check again.
When you eventually find it dry the boat out, place the boat with the leak almost flat, mix up some epoxy resin and cover the area, spreading it well and well past the leak.
Test it again after epoxy has fully cured.

Bob

[tigertiger]

Another possible source of entry is the rudder tube.

Check that the top of the rudder tube is not below the waterline.

Allow for the stern going down under power as well if she does this.

[White Ensign]

Surabaya, as mentioned before Rudders and Propshafts are the ususal suspicious objects. Strip them down and grease/oil them new. If now there is some leackage, take everything out, let the superstructure off and take it in the pond. Now check where the water comes in. To seal or restore a wooden hull is not easy, but not impossible either. The best way to seal it (from the outside) is by a mould called G-4. Polyurethane-mould- not cheap but does a prefect job. Or by 2-K Epoxy-mould with a layer of very fine matts inside. To seal a hull from the inside is something I would not recommend. If the water is comming through the panels/planks and you "close" the hull from inside, it still can effect the panels. Means that the will start to expand and open the cracks more and more. The leackage will not become better.....
So, sealing must be done just from the outside. Sealing from inside means, to "lock" the wood. And any incoming water will definately find a way to soak into the wood...., but not dry out. A rotten hull is sure after a while....

Hope that was out of any help,
Jörg

[surabaya]

Hi. I checked rudders, prop shafts and prop shaft mounts and all OK.
It seems that the water is coming through the joints at the keel and between some of the joints between the panels. The hull is made up of diagonal pieces.
i really don`t want to ruin the finish on the out side.
Just a thought, but what if I give a few more coats of lacquer of some sort? :-\

[Colin Bishop]

If the finish on the outside is good then how come it has gaps where water gets in?!

I don't think laquer would be up to the job but what you could use is the variety of epoxy resin used for finishing purposes. This is a two part mix which would go on like a coat of varnish but give a tough impervious coating. I've not used it myself but there are others on here who could probably point you in the right direction.

Colin

[surabaya]

Hi, colin.
That is exactly my problem, it is almost like the paint / lacquer is full of minute holes, but to the eye it looks OK.
That resin sounds like the answer, does anyone know where to buy it?

[malcolmfrary]

If you have a good idea of where the hull leaks are, and they are hairline cracks or pin size holes, you can as previously suggested arrange the hull so that one of them is at the lowest point, and flood that area with a thinned varnish.  This can soak through, and will soak into the wood around the crack.  As it dries, it seals.  Repeat for any other known leaky spots.
The first time I tried this I used white paint and wound up with a nice white interior, and a couple of white streaks where the holes were.  They never needed any further treatment.

[tigertiger]

Turning the problem upside down.

Take out all the electrics.

Fill up with water and see where the water gets out.
The dry her out thouroghly after wards.
You do risk some warping, but this should go back after she dries out again.

I know you want to save the finish, but there are no shortcuts. If you do nly seal the inside then eventually the planks will peel off from within, as has been suggested before.

[surabaya]

I have now found the reason for the leaks. This was an old boat stored in an attic for years, made with a double skin of diagonal ply. Some of the joints have failed. I now intend to strip it back and repair properly and then coat with resin. I have removed all the superstructure, fittings and rails etc and I`m just about to start on the hull.
I will save this old girl. I want some more of those comments I got when I took it to the canal.
What I need to know is, how much of the paint must be removed before applying the resin. I.e just a rub down, a real good sanding or completely back to bare wood. At the moment it is painted with high build primer, primer and then car paint.

[Shipmate60]

surabaya,
If she was mine I would rub all the paint off!!
I would repair as well as I could, but be careful if you use wet-and-dry as some of the original wood will have completely dried out.
If you get it wet the wood will swell and the moisture will travel a surprising distance inside the fibres.
For double skinned hulls my way is to prepare the inner hull as if it was the outer, but not paint it.
Then replace the outer hull planking and do the same, once fully watertight then paint her.
One of the main problems with older models is that the wood has dried out and slightly shrunk which can put strain on the glued joints.
That is why I favour a thin epoxy resin mix and paint the whole inside of the hull, then the 2 outside "hulls".
I get my epoxy from Yacht Chandlers and use the 24 hr setting.

Bob

[BobF]

Hi surabaya,

I bought an old plank on frame trawler which had the same problem.

I stripped out all the electrics motor etc, and then used twelve hour setting epoxy resin thinned down seventy five percent.

I  cleaned the inside of the hull as well as possible, and poured the resin inside the hull. As it is so runny it filtered through into all the cracks, and I just wiped away the small amount that soaked through with a cloth soaked in meths. It has left the outer finish almost un marked. A few planks raised slightly, but this looks like most trawlers any way.

There is a ready mixed paint product available for doing this job on rotted timber on old window frames etc. but this is quite quick drying and would not soak in as well. I just went to check what it is called 'TECHNIFIL'

I can't believe what I just discovered as a result. This is an old tin and the label has virtually rotted away. on closer inspection, it is just a tin of cellulose thinners with a paper label stuck on, and obviously a small amount of I assume styrene or similar to give a structure when it dries.
Bob

PS just had a thought, If you do try this method, don't thin with paint type thinners as this will destroy your paint finish. I used meths, but on thinking back this was only luck not forward planning as I often thin with paint thinners.

[surabaya]

I think it would cause too much damage if I try to remove outer skin, so maybe I will remove paint and then repair as best possible. Then coat outside and inside, just to be sure.
I know it means repainting, but hopefully it will last a lot longer than if I just do the outside plus give a bit more strength.
I think I will stay away from the wet & dry, just in case. Maybe a little weak paint stripper first and then a lot of sanding :(. Oh, how I hate sanding.

[Shipmate60]

surabaya,
Best of luck, but it will be worth it when she is looking pristine in her new paint and leak free!!

Bob

[White Ensign]

Coating Inside is not very recommendable. Imagine the following scene: Well covered outside, runs well- but just a little water, a bit of bilge is coming inside. The wood is completely coated outside, but some capillaries are in the surface. So the water will find his way in the wood and spread UNDER the coat.... and never will find his way out again. So it will start to become faulty anyway.
I have had this experience of a totally rotten hull, may safe you from the same. Don`t seal the hull inside. If there is a little water in- fine, it will easily find his way out if you ventilate your boat after sailing.

Regards,
Jörg

[surabaya]

Thank`s  Bob, I will put on some pic`s when it is done. As you may have guessed, I am a little stubborn and don`t intend to lose this battle. She Will sail again.
Thank`s also Jorg, I must admit, I did not think of that. But with the outside sealed , I supposed sealing the inside won`t be needed.
And thanks to all other comments too.
Now I am going to check out some of the other threads for some info about coating the outside.
For example, Do you coat the hull with resin first and then dab on matting or wait for first coat to dry? And how to keep reasonable smooth to cut down on the dreaded sanding?

[Willit]

Another possible source of entry is the rudder tube.

Check that the top of the rudder tube is not below the waterline.

Allow for the stern going down under power as well if she does this.

woops that explains why my Springers rudder tube was leaking around the flange!

I ran some CA around it and it seems to have cured it

I still keep a big wodge of kitchen roll nearby in the hull to catch any water though