Making a Mortise

As I’ve said before, a large part of timber framing centers around making round holes into rectangles.
It usually starts with a drill to get rid of most of the wood. Then you finish up with a chisel in one hand and a mallet in the other.
Here is a video of someone using large chisel to square up the holes left by an auger or drill

I’d say his technique is a little slow as he is trying to take too big a bite with the chisel. I prefer to pare less off at a time. This way it is less likely that your chisel will go off course and mis-align your mortise. It’s pretty easy for the chisel to go off course if you bury it in the wood and just keep pounding.

This video shows the latest technology of using a chain mortiser to remove most of the waste from the mortise. It still requires some chiseling to make it square and smooth and to fine tune it for the tenon. If you have a lot of mortises to make, this would be a good choice.

The chain mortiser is fast and effective. Probably worth the purchase price if you have a large house to build.

My choice for a small timber frame project would be a hand drill with a guide and a large Forstner bit (described in this post) to remove most of the waste in a . Followed up by a large corner chisel and 2″ timber framing chisel.