Filler recommendations for wood floor
I am working to repair a wood foor in my kitchen. There were some spots where the previous owner had added on and filled 1/4 inch gaps in the wood with some type of wood filler. The gaps are several feet long. They have now started breaking apart and the filler is coming loose and needs to be replaced.
My dilemma is I'm not sure what type of filler to use. I've heard some say to use a non-hardening filler to allow for the shrinking and expanding, but this doesn't seem appropriate - just doesn't seem right to leave a "soft" joint of that size in a high traffic area. I've tried a couple of "stainable" wood fillers from Minwax, but there consistency, while solid, doesn't seem quite right either.
Whatever the previous owner used, it held up for many years and I hadn't even noticed it was a "fill" until it started to break loose. I'm just looking for any recommendations from folks on what would be a good product for this. If you can name specific brands/types that would be great.