After rereading this I realized it was a rant, but sometimes you just have to get it off your chest.
I am trying to take a really long view of all the projects I'm doing on MaJic Carpet. I am not anti balsa, but there is no way I would spend a big chunk of change on a balsa cored rudder even if I was concerned with maintaining OD. While most of the strength is in the skin, why would you want to haul around a soggy compromised rudder. The first time the skin is penetrated below the waterline, or maybe even above it the core will become saturated and begin the cooking process to turn the balsa core to mush. At that point you have reduced the strength significantly. If I were paying for one of these things I would go with a foam core and the second choice would be wood. At least with wood when the skin is penetrated the movement of the moisture is slower and there is still substantial compressive strength in the core for a long time so the skin has support and the lateral strength required.
I have no idea how it was done, but one of the PO's sometime over the years managed to impact the bottom of the rudder pretty good. The front bottom corner had been crushed inward (the question could be asked if the balsa was already soggy so it couldn't support the skin, or if it was just a big hit). So the source of the water was this small hole and the jillion blisters on the skin. I have no idea how long this condition had existed, maybe the rudder would have held up like that for a long time. When I cut a chunk of the skin away on the rudder the balsa was black, but firm, not as bad as the area around the exhaust which was black soup. I want to be able to sail this boat hard when necessary and do not want to have any fear that the rudder could give way. That would be a very bad day sailing for sure.
