Chopping mortises in absurdly narrow stock
The topic of this year’s Working Wood in the 18th Century conference at Colonial Williamsburg is, basically, small stuff like traveling boxes. Journeyman cabinet maker Kaare Loftheim undertook the daunting task of reproducing a small bracket clock. (The name comes from how the clock movement is mounted in the case. These are clocks that might sit on your mantel or a bookshelf). The case has a very small face frame on it. The rails and stiles of the frame are just 5/16 in. thick. The door on the case has a thin frame, too. Those parts are 9/16 in. thick. So, Kaare need to chop mortises in some insanely thin parts. The greatest potential problem he faced was blowing out the sides or end of the mortise when chopping it. Take a look at the photos to see how he dealt with those dangers.
You might be wondering, like I did (and I asked Kaare about this) why he didn’t leave the stiles long, so that there was a horn on both ends. That greatly reduces the chance of blowing out the mortise’s end grain. He had a good answer: He was making the clock case from some very choice mahogany and simply didn’t have enough to waste some on horns. Sometimes, practicalities like this force us to adapt from our usual techniques (Kaare said that they normally do leave horns on the stiles when making doors.) I think he did a great job of adapting.
See all of the coverage from the Working Wood in the 18th Century conference at Colonial Williamsburg.
Gang narrow stiles. These parts are just 5/16 in. thick. To keep from blowing out the sides of the mortises as he chopped them, Kaare clamped the rails and stiles together.
Save the end grain. Here, the parts are pushed against a planing stop built into the bench. It provides enough support to prevent the end grain from blowing out.
Removing waste. Using the chisel with the bevel facing down, Kaare is able to pare out waste, which is much less violent than pounding the chisel into the mortise, like one would do on larger stock.
The finished mortise. It's small. You can see the mating tenon in the background.
Another trick for mortising. This is the stile for the door, which is 9/16 in. thick. It's sandwiched between a notched block and a clamping caul. This protects both the end grain and the sides of the mortise.