Mitered Face Frame Joints

Tips for joining face frames of adjacent cabinets together at a 45-degree angle. May 22, 2006

I am doing a kitchen and the customer wants the front cabinet of an island to look like a piece of furniture. The piece has a 36" front and both sides go off at a 45 degree angle. On both sides right at the 22.5 degree faceframe joints there are two stiles 35" long that have 22.5 degree faces that will glue together. My first question is: can I just glue them together or do they need biscuits of splines, etc. My second question is: how does a person clamp two faces together that go off in a 45 degree angle?

Forum Responses
(Cabinetmaking Forum)
From contributor S:
Have you looked into getting a set of 45 degree lock miter cutters? I bought a set to do octagon curio closet project and it made life a whole lot easier.

From contributor L:
To do this it is important that things be straight and flat. Cut your 22 1/2 angles on your two pieces. Then put them flat on your work area with the angles pointing toward each other and the long side facing up (towards you). Put some strong tape on the joint. Turn over and apply glue to the joint and fold the pieces together. Use a clamp or more tape to hold them together. Wait for the glue to dry and remove and sand. There you have it.

From contributor J:
I do this all the time, just like Contributor L described. The one thing I add is a 1/8" masonite spline in the joint. I usually make the spline 5/8". Make a kurf cut down the length of both pieces about 3/8" deep and you're in there.

From contributor P:
I've done them successfully with biscuits. I cut a half dozen pieces of 3/4 plywood into temporary wedges that fit inside the 22.5 (the back of the faceframe), and used ratcheting web clamps around the FF and each wedge to draw the 2 pieces tight. Seems like a lot of work, I know, but the ones I built this way have held up great.