Sharpening the chisels for a benchtop mortiser is similar to sharpening a bench chisel and minimizes clogging and friction while cutting.
Most woodworkers wouldn’t use a new bench chisel without sharpening it first. I applied that same logic. First, I cleaned each hollow-chisel and the auger bit with lacquer thinner to remove oily residue and the clear coating that came on these cutters. Then, I cleaned the inside bore of the chisel and raised a wire burr on the cutting edges using Rockler’s Mortise Chisel Sharpening Set (item 24727).
I proceeded to remove the wire edge and grinding marks on the chisel backs with 320-, 400- and 600-grit emery wet/dry sandpaper, taped to my cabinet saw’s iron table. Finally, I lapped the backs to a mirror finish on my Veritas Mk.II Power Sharpening System. I believe this prep work was worth the effort: the bits cut more cleanly and easily than bits straight from the package, with the exception of a few cases where clogs occurred. Only two of the chisels turned blue after cutting 16 mortises each in four different woods.
