Lee Valley recently added Japanese milled-tooth plane-maker’s floats to their product line-up, and I’ve been using them the last few days to tweak some through-mortises. These are similar to the previously available Xfine mille d-tooth files, but the floats are tapered in profile making them more adaptable to different size openings and special situations. Both floats have arc-shaped teeth that remove tiny shavings on the push stroke. One version has teeth on one face only and the other has teeth on one edge only. The combination of safe edges and sharp teeth allow you to remove small amounts of material in a precise way, while avoiding damage to adjacent edges.
Like the files, the floats are capable of removing material aggressively while leaving a smooth surface behind. I found the floats to be less grabby than the files. The tapered shape means that fewer teeth are engaged at the start of the cut and it’s easy to position the tool by tilting it into a corner as the cut progresses. The edges cut nicely into an inside corner, but no further.
These are specialized tools, not everyone needs to make minute adjustments in confined spaces. But if that type of work is your specialty, then these floats move into the necessary category. They work well, do a nice job and limit the risks that come along with other tools used for this type of work. While the floats do a nice job of finishing off the edges of mortises, I prefer the files, especially the larger size flat files for adjusting the size of all but the smallest tenons. Those are a bit beefier and cut faster. All in all, this line up of floats and files are good tools and a good value.