Transom leak through hull fittings

[ewzachmann]

I've tried to my amateur fixes to leaks that occur through the hardware that goes through the transom. The hardware that secures the rudder and the hardware that holds the ring so that the rudder does not sink if the rudder falls off. The rest of the boat is fine..this seems like a pretty easy thing to fix, but I am not sure what to do. The transom is a bit 'tired' and seems a little squeezed where the hardware sandwiches the fittings.

Should I reinforce the transom with some kind of transom pad and redo the fittings? How would I do that?

Thanks

[dannyb9]

my '68 ds1 had that problem of leaks at the transom.. i decided the wood blocking inside the middle of the transom was soft. i cut the fiberglass off the transom 'reinforcing block' and sure enough, the wood was rotten. i set a piece of 1/2" plywood in silicone sealer to replace the original wood and reattached gudgeons etc. i did not replace the fiberglass covering. better to let the wood 'breathe'. no leaks so far...be aware, there are several versions of daysailer out there. i dont know how your transom is made

[GreenLake]

Danny's right. A "soft" or "tired" transom means that you have rot in the wood reinforcement. Cutting it open, from the inside and removing all the damaged wood is the first step.

Leaving the wood to air is one possibility.

I would usually have suggested another route. Fit a replacement, and then coat it with epoxy (laminating epoxy such as SystemThree's Silvertip) on all (!) sides, and push it in place. Then cover with a few layers of fiberglass cloth and/or mat using the same epoxy (mix a separate batch so it doesn't cook before you can use it).

Even if you've never done epoxy / fiberglass work, it's not hard, and SystemThree or WestSystem have useful guides on their websites.

The key thing is to remember to saturate all holes that you drill with epoxy, so there's an unbroken seal all around the wood. You can coat any bolts with oil or wax and insert them while the epoxy is still liquid, it will harden around them and you should still later be able to remove them.

Normally, you would use a marine plywood. If you can't get that, use the best quality (no voids) exterior grade you can get. In that case I would cut the piece into 3-4 strips and glue it back together with epoxy (laid flat on some plastic sheet or wax paper and with minimal clamping). The joints will be plenty strong, but the fact that you now have "seams" prevents any water from being wicked into the entire piece of wood.

Oh, and any wood that you seal in epoxy should be thoroughly dry.

[ewzachmann]

I think that you are right in that the transom is 'tired' and needs to be reinforced in some manner, but I am having a hard time picturing what I cut and how I replace things. The transom is fiberglass on the inside (cockpit?) and the hull and the wood would be sandwiched in between. Do I have to pop the boat apart? What do I cut? I don't have much experience (obviously) and am having a hard time even describing my confusion.

[dannyb9]

there are several models of daysailer. mine is a '68 ds1. ds2 has a different transom design and might require a different repair technique. what model and year is yours?

[GreenLake]

You got the right idea with the sandwich.

In this case the meat, i.e. the wood is rotten, and to get at it, you need to take one of the slices of bread off.

I think, in this case, one usually cuts the fiberglass on the inside, it's a bit harder to get to, but marks from the repair will be less visible.

If you have the wooden floor and shelves, those have to come out, but there's no need in trying to take the deck off.

A Fein Multimaster would seem the ideal tool to neatly slice the fiberglass along the line where it meets the hull at the bottom and sides, and then in a line across at the top - as high as you can reach.

Once youv've made that cut, it should pry off the wood more or less easily. You are then free to dig and chisel out the damaged wood. I haven't done that particular repair myself - so I don't know how easy it is to get at the wood and how much you can expect to be affected.

You could always start by cutting a simple square around the leaking fittings, to check whether the damage is localized, but if things got to the point where these leak, I would expect the whole transom, or at least it's bottom part saturated and rotting.

After digging out all the rotten wood (and then some), I would treat any wet but firm wood with a generous application of borax. A commercial preparation is available from SystemThree as RotFix. Their kit includes instructions and a very thin (like water) epoxy which can be used to seal the wood after it has dried out thoroughly(!).

The same stuff is useful around the house, when you have a localized spot of rot and want to treat and restore the wood rather than tearing things apart to replace it.

Back to the transom. Once you have removed all questionable wood, treated, dried and sealed all salvageable wood, you need to cut and fit a replacement piece - from marine plywood. A gap of up to 1/8" in a few places isn't an issue, because you can fill that with epoxy without loosing too much strength.

Then you seal you new piece and glue it in place. You can use an epoxy formulated as glue, such as SystemThree's GelMagic, or mix your own by following some other vendor's instructions on thickening epoxy. Gelmagic or thickened epoxy would be nice because it doesn't "run", like pure laminating epoxy would.

You're then ready to glass over the wood (no need to wait for the glue to fully cure). Instructions for that can be found online. Finally paint (to protect from UV) and you are done - except for drilling holes for the fittings (and be sure to make sure any holes are properly sealed).