The Planemaker's Float
An Easy-to-Make Tool
As collectors of antique tools, we know that plane-makers' floats are very hard to find. Most early planemakers made their own from soft-steel or worn out files. They were rarely tempered and needed sharpening after the making of two or three planes. With this constant sharpening, they wore out quickly and were discarded, leaving very few to be passed down to collectors.
A float is a rasp-like tool having a series of sharp parallel cutting teeth. It is made in two basic shapes: an edge-float and a flat-sided float (see Figure 1). Edge floats have teeth on the edge and are fairly thin (1/8 to 1/4"). They resemble fat saw blades and are used to clean out the narrow wedge slots on bench planes. They are also used to cut wedge slots in molding planes. Flat-sided floats have teeth on the flat side and are much wider (3/4" to 1-1/4") than edge-floats. They taper from the rear to a point at the front tip of the tool. These floats are used to remove the waste stock and create a smooth, flat bed for the iron.
These tools are very easy to make. All you need is a piece of soft tool steel or a worn-out file. If you use an old file, you first must anneal or soften it. Once this is done, coat the blank with machinist's layout fluid or a black magic-marker. Using a sharp scriber, scratch out the shape you want. Make it about 6" or 7" long and add 1-1/4" to 1-1/2" for a tang. For an edge-float, use steel 1/8" to 1/4" thick and lay out the teeth on the edge about 3/16" apart, using a trysquare to keep the teeth parallel.
For the flat-sided float, use a blank 3/16" thick by the width you want. Use the trysquare and lay out the teeth about 3/16" apart.
Now, using a triangular mill file (the same file you use to sharpen your hand saws), cut the teeth, starting from front to back. Follow the layout for the teeth you just made. Keep the rear edge of each tooth vertical and cut down so each tooth is the same height. It's very important to keep the teeth the same height for smooth cutting action. Next and last, shape the tang and add a nice handle, to complete the float.
If you're making wooden planes, use your floats and see how much easier it now is to accurately cut the iron beds and wedge slots. If you don't make wood planes, these reproduction floats will make a fine addition to your collection!