regitregit or tigertiger
just the way I feel today my mate - all back to front Hi there, building a large hull with balsa wood - couple of thoughts when I read your posting. The only weakness, as you may know, with balsa wood - its prone to be a soft timber - dents/breaks easily. By impregnating the balsa wood with epoxy/polyester resin, it does toughen the outer skin. This allows you to work the material sanding and so forth quite easily. By adding matting it does strengthen it - but when you plank the hull, if you double diagonal plank with balsa or even triple plank it, you are producing a form of plywood. Grains going in opposite direction which increases the strength of the balsa wood immensely. This would be a preferred method for me if I was making your project. I would carry on the steps you are going to, fibre glass tissue on the outside and matting on the inside.
There are alternatives to tissue and matting which would aid the strength as has been mentioned on this thread - nappy liners as one. Another material for adding in is the old net curtain or even silk. Admittedly, it doesn't give the same strength but, it does hold similar properties.
To answer BobF's query, yes, they do use balsa in racing yacht/speedboat hulls at 1:1 scale. However, balsa is cut into 1 inch square blocks and then laminated end grain on. This allows the resin to penetrate the balsa wood blocks and form an immensely strong bond. The only disadvantage is, when the hull is damaged, its extremely difficult to repair.
Hope this is of some help.
aye
john e
bluebird