Fixing water damage at beam case in place?

[Kris]

Ok, so I got this tricky problem with my Pahi42:

Apparently something caused a leak between the second beam and the casing, resulting in rotten plywood in the side of the beam casing.

Obviously the best would be to pull up the beam and fix it properly, but that beam supports the pod and the cockpit and lifting those, including the engines suspended below the cockpit is not feasible in the next couple of months as I lack a suitable crane for it.

So I am wondering if I can do a "good enough" repair in place, without lifting the beam...

Obviously there is some risk of overlooking hidden rot, but it looks like the wood of the beam itself, especially the part made from hardwood is still fine, just that the plywood beam case is rotten though.

I started removing the completely soggy and rotten plywood, and you can see the hardwood of the bean coming though (between the red lines in the picture). Somehow the surface cover of the beam is gone too, maybe I damaged it when opening this up, but I am pretty sure if was damaged before as well. On the second picture you can see the overall situation a bit zoomed out to give you and idea what I am talking about.

The blue arrows show where the water can enter and it drains very poorly there, especially when some hard to remove dirt accumulates in the space between the beam and the beam casing.

I am currently unsure how to proceed, but my initial idea is to open the beam casing at the damaged part open even more to be able to repair the surface damage of the beam without moving the beam. Then I can put some oil-paper of so on top of it and epoxy a new plywood patch back in place to cover the hole and make it water tight again.

I am aware that this would be very much a hack job, but it seems to be mainly a matter of preventing further damage in the hope that it is good enough until I find an opportunity to fix is properly (which might not happen anytime soon to be honest).

Anyone here ever faced a similar issue and might have a different idea how to fix it?