Ok so I cut a small 4" x 4" piece of the skin off and just by luck that exposed two very different blocks of balsa. I should also note that in the 40" x 24' patch I had been working I pulled out 48 oz. of water. One of those blocks felt dry to the touch, was nice and firm and white and the other, not so much. The 2nd block was essentially dry but was as easily compressed as a marshmallow and quite dark. Not at all what I wanted to see. And while the sample was a small one it could easily be said that is a 50% failure rate. The bond of the skin in this patch was good and similar to the larger one I pulled a few weeks ago.
The small patch I pulled is maybe 10" from the keel so this is an area of high stress area where the shear strength of the balsa is more critical. I have tried to rationalize my options, but the only one that I think I can live with is to open this up and replace the core. A second option might be to just add multiple layers of heavy glass to make this exterior skin much more structural than it is now. As I move outboard from the keel I might become more forgiving of some soft balsa. On this port side the skin is just seriously chewed up with osmosis zits. Relying on any strength from this degraded skin is not a great option. So new core and new skin is likely going to be the fix at least anywhere parallel to keel. With weakened core and a weak skin in this area it is not that difficult to imagine a catastrophic failure.
Unfortunately much of this part of the project is going on hold for several weeks while I recover from carpal tunnel surgery on both wrists. But I do think I can continue the drying process across the rest of the hull, since that is a fairly low stress/effort project, but we will see how that goes.
