I have uncovered a 100 year old wood floor in a place that I am going to run a soda fountain. I romoved old underlayment and tile to get to it. The floor is sound, but has gaps where the wood has come off over the tounge and groove. and a few holes where they might have ran plumbing at one time. I covered the bottom side of the holes in the basement with plywood so they could be filled. What should I fill the holes with? There are so many gaps that I may just leave them or fill them with a clear caulk, would that be ok? What would I use? I would like to refinish this very old floor. I have heard that there are 2 types of sanders, the heavy duty type and a vibrating lighter duty type. What is suggested? The current surface has no finish left, and is quite dirty.