I have a seepage (2 cups/d) at the base of a through-hull housing that holds the depth sounder
transducer. This transducer is removable - can be extracted from the fitting like a paddlewheel speed transducer.
This housing is fitted with the usual large diameter nut that screws down to clamp the through-hull to the hull
My proposed fix (from inside the hull):
- Undo the nut and backing pad (disc of plywood)
- Scrape away as much of the polyurethane sealant
that was between the backing pad and the inner hull
surface, as I can (not easy)
- Apply new sealant
around the base of the through-hull
- Cover with a new backing pad, with bottom-facing edge chamfered
- Redo the nut
If anyone has attempted this type of fix, with either success or failure, I'd much appreciate input. Perhaps an external fix (remove the housing entirely and re-bed) is the only approach worth considering.
I'm actually slipping the boat. But I can't risk removing the through-hull; it is plastic and was bedded with polyurethane
, so it could crack or break if it is forced. The supplier (B&G) cannot provide a replacement housing (old model), and this sounder is part of a B&G suite on the boat that includes displays and other transducers (speed, wind
etc.). If I could remove it without damage, re-bedding would be my preferred approach.