I'm finding all kinds of new uses for my table saw, and this little jig took about 5 minutes to make. It's just a couple of 45 ° slots cut into a board to fit your reinforcement strip. Make the slot deep enough that your strip is going to be almost fully supported.

Load up your strips and then run them through the drum sander, or if you don't have one, then a hard sanding block will do the trip, but not as much fun.


Flip them over and run through the drum sander again, A few minutes work and you have your accurately mitered back reinforcement strips.

Hope you find this useful.