Thursday, December 19, 2019

Chair Seat Mortise Jig

For the last few weeks I've been playing around with making a jig to aid drilling chair seat mortises. It is not a new idea, I've seen similar jigs in chair making videos but with little detail on how they were made. Most of the time has been spent scratching my butt and playing the "yes but game" with little progress.

Here is where it is right now. I've been using a seat blank that split to try proof of concept and it seems to work. What is needed are wedges of the correct degree that will fit on both sides, there is too much flex with just the single shim.

Once correct sized wedges are in place the jig should work a treat.



  1. Steve D8:48 AM

    If that's a Delta drill press, I have had the same one for about 30 years. The odd thing is that yours is coated with rust in Arizona while mine is pretty clean with no rust in a somewhat damp Connecticut basement. Go figure.

    1. Steve,

      Good eye. It may be a year or two older than yours but still made back when Delta made good equipment. It took it awhile for it to make it to AZ and the desert. The first 15/20 or so years were spent in my shop in Houston, TX after that, while I was trying to keep beans and tortillas on the table and flying over most of the world, it was stored in a friends barn outside Fort Worth, TX. for 10 or so years before being rescued to the desert a couple years after we moved to Tucson. It earned its rust :-).

      BTW, it is the only power tool from the Houston shop that is still in use, a pretty good testament to how well it was made. I still have and use most of the hand tools that were rescued from the barn.


  2. Steve D4:22 PM

    Mine is an early Taiwan machine. It doesn't get heavy use so it's been fine. I think I paid $219 for it and brought it home in my VW. I also bought a lathe a few years later which is a total piece of cheese. One project and the drive needs to be rebuilt.