Just about to haul to attend to minor refinements on the repower and I want to fix a leak at the rudder post. JC I borrowed your shot,
We put a load of sealant on the underside of the hull and the external plate but after running for a while we get water in through the base, per the pic.
I'm thinking of putting a stainless plate over the top and through bolting to make a sandwich of sealant and a stronger securing point for the bolts, instead of just washers on the glassed in plywood pad we replaced.
Anything you do in regards to adding to the exterior of the rudder port is just a bandaid... You need to fully remove the port(s) clean off the old bedding and re-install.
For best results, use 5200, (fast set is fine & will get you to step 2 faster), re-install the port(s), but only tighten the nuts down with finger pressure.
Wait until the 5200 sets up, (5-7 days for regular, 2 days for fast set), and then tighen the nuts and bolts with a wrench. This will squeeze the cured 5200 into a compression seal that should be good for many many years.
We did everything except the finger tight first, we went straight to max with Sikaflex 291.
We will certainly take it all off again & redo with 5200 Fast; when first back in the water there was no leak, only started to leak after 20 hours or so...which was about day 4!! I think there is movement there under way as the nuts bear down on washers on glassed ply, we've blown most of the paint off the rudders so it is a lot of pressure, there must be movement in a turn.
Keen to do what you say and then more, complete removal & re-assembly with a stainless plate on top with a hole to match the rudder post, then tightened on to a bed of 5200 can't hurt, can it?
You might want to keep it all bronze so you don't run into a galvanic corrosion issue. Also it is easier to work with. A quick soak in 50/50 muriatic acid/water bath will clean up your old parts - just don't overdo it.
