[caption id="attachment_9407" align="aligncenter" width="400"] To test the mortisers, the author used a new 3/8" chisel in every machine and made four cuts each in hard maple, sugar pine, white oak and red cedar.
A mid-sized chisel was my choice for this test. I chucked a new, 3/8" chisel into each machine after carefully sharpening them. The chisels were obtained from an independent source to level the playing field in terms of chisel quality. I adjusted each cutter to create 1/16" of clearance between the auger bit and chisel; this provided consistency between the test tools and good chip evacuation. The depth stops were set for 1-1⁄4"-deep cuts. I cut four 6”-long mortises in hard maple, sugar pine, white oak and red cedar, in that order. All of the test pieces came from the same initial planks of stock. I felt they represented a good variety of hardnesses, densities, potentially tough grain issues and resin contents. In other words, realistic challenges for these mortisers. While I anticipated that hard maple and white oak would test these mortisers’ mettle the most, sugar pine actually posed the greatest challenge. Its resins seemed to make the chisels more prone to clogging and smoking than other woods. If a chisel was going to turn blue, here’s where it happened — although that only occurred twice. Still, even blued chisels were able to proceed from pine to oak and then cedar without a noticeable difference in sharpness or chip-clearing performance.