Q: We have about 1″ cracks between the boards of our 1850 pine floors, we would like to fill them, but we do not want to sand/refinish the floors (as they had been a few years back). Any suggestions?
A: 1″ cracks you say! That is not a crack. It’s a drainage ditch. Sorry. Couldn’t resist. That is a big gap. Can I assume that this is not tongue and groove, and there is no sub floor beneath this pine?
What I am thinking is that you could make a stiff paste with fine wood dust and wood glue and press it into the gaps. I am not sure that it would not sink through. It would have to be really a stiff mix. Perhaps jamming some paper into the gaps first or cutting tight fitting wood strips and banging them in would give this paste something to sit on. Before doing this, I would apply painters tape to each side of the gap so you don’t smear the glue-dust mix all over the surface of the floor boards. If the color is going to be significantly different, make sure you push the mix below the top of the boards so that when it hardens you can perhaps apply another color matched latex filler on top. Then when all of that is done, you may want to have the floor lightly buffed with a polisher and fine screen pad, and recoated.
If you can come up with a more workable solution, please let me know. I hope this helps.
Reader comment: The old style method was to fill these cracks with a combination of linseed oil, sanding sawdust, and wax.
Response: I don’t think that old method would be a very good idea if someone wanted to finish these floors with polyurethane. I don’t think they would get any bond across the gaps and would end up having the finish peel and flake along the board edges. Interesting idea though.