I am restoring a very old wood floor. I have removed thousands of nails (at least it seems like thousands). There are many gaps between the planks that you can see the tounge. These gaps are up to 1/4". Is there something that can be poored over a wood floor, like a thick polyurethane or something that would just level this out??? I have been told that ripping strips and glueing probably won't hold and take forever. I am affraid of any wood filler, and what it might look like or if it will hold. I know that polyurthane would be a good finish but isn't thick enough to just fill the gaps. I am hoping someone will know of a product or solution for me. HELP!!!