Weeping Deadwoods

[pelorus32]

We've got a minor weep from the stern timbers on our boat. She was first launched in July and has not leaked a drop except for this minor weep in the stern timbers. The structural keel has a stern deadwood below it and a stern knee above it. The weep is out of a couple of bolts under the engine (where else). They have cotton grommets on them and are plugged below. We have put a gentle tightening on them but it still continues. These bolts only go through the timber keel and the aft deadwood. The stern knee finishes aft of them.

No stopwaters were installed in these timbers. I suspect that the water is entering aft of the rebate and tracking through between the keel and the deadwood then up the bolts. The timbers are about 12 inches wide just aft of the rebate. What diameter stopwater would you use? How tight should it be to drive in? I'm concerned about breaking a stopwater driving it in. Also what is an appropriate (maybe Australian) timber for the stopwater? The timbers are all Tasmanian Blue Gum and have black jack on all the faying surfaces.

Regards

Mike

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[Peterduck]

Blue gum could take quite a while to swell up after the initial immersion. One of my mates has found that his sternpost, which I think is Spotted Gum is still swelling after two years immersion. Probably the best species for a stopwater would be Oregon Pine / Douglas Fir, as it swells generously and fairly quickly. Try to find some fine grained stuff, around 30 rings to the inch. The diameter would relate [at least partly] to the size of the boat. For one of about 30ft, I would think about 3/4" would suffice. The fit doesn't have to be more than a tap-in fit, as you are relying on the swelling of the timber to create the seal. The end-grain in the stopwater should be placed parallel to the seam being sealed, so that the maximum expansion is across the seam. Stopwaters are fitted where the bottom of the rebate crosses the seam between the relevant backbone timbers. In that position, it's not really convenient to try to fit one post-planking, much less post-launching. I would suggest monitoring it for another year and see how it is then. Clearly, the inflow is not of an order that an automatic bilge pump cannot keep up with it.
Peter.

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