Master Your Mortiser Pacific MO
St Peter, MO
Saint Louis, MO
Gray Summit, MO
M-SA 6 am - 10 pm
SU 8 am - 8 pm
Master Your Mortiser
Master Your Mortiser
Shop-tested techniques guarantee great results
by George Vondriska
The first time I used my benchtop mortiser was almost my last. It was tedious to set up, difficult to operate and my results stunk. But now the mortiser is my first choice whenever I have mortises to cut. It turns out the problem wasn’t the machine—in fact, the newest benchtop mortisers do a great job. Instead, the problem was my inexperience. I discovered there’s a learning curve to successfully setting up and operating a mortiser.
Read on to learn the techniques I use to get consistent, professional-quality results from my mortiser. If you follow these methods and mortising is still a struggle, your machine’s fence and hold-down may need tuning.
The hollow chisel and auger bit work together to cut square mortises. The auger drills a hole and then the chisel squares the corners. Chips produced while cutting are lifted by the auger and ejected through holes in the chisel.
Start Sharp, Stay Sharp
You’ll get better results with less effort if you take a few minutes to sharpen your bit and chisel before each use.
Sharpen the auger’s flutes with a small auger file (this one’s from Nicholson’s miniature file set #42030, about $17 at Amazon.com). An auger file has smooth edges that won’t harm adjacent surfaces during close work. Hold the file flat on the bevel and move it forward only, toward the cutting edge.
Sharpen the chisel’s inside bevels with a round slipstone (about $15 at woodworking specialty stores).
Hone the outside faces on a flat stone, using even pressure and a circular motion.
Insert a DIme to Install the Bits
To work properly, the auger must slightly project beyond the hollow chisel. Here’s an easy way to achieve the perfect projection. Temporarily install the chisel with a dime squeezed between its shoulder and the machine. Then lock the auger in position with the edge of its cutting flute even with the chisel’s tips. Remove the dime, slide the chisel’s collar tight to the machine and lock it.
Instantly Align the Chisel
To create perfect mortises, the chisel must be parallel to the fence. It’s easiest to place a board against the fence, move the fence forward and pivot the chisel until its face is flush with the board.
Arches Set the Depths of Cut
Mark the tenon’s length on the end of the workpiece. Then lower the chisel. Lock the depth-of-cut stop when the tops of the chisel’s arches are even with your line. This method assures that your tenons will seat properly, because it automatically creates a mortise that’s slightly deeper than the tenon’s length.