I know someone with a wet transom core but the wood is in very good condition.
My idea is to draw a vacuum at the bottom, drill 1/2 inch relief holes along the transom top. Suck the moisture out over a couple of days, then run acetone through it to displace remaining moisture, then finish with low visc epoxy, drawing it through with the vac pump.
My idea is to draw a vacuum at the bottom, drill 1/2 inch relief holes along the transom top. Suck the moisture out over a couple of days, then run acetone through it to displace remaining moisture, then finish with low visc epoxy, drawing it through with the vac pump.