Corner Cabinet Joinery

Here are several suggestions for ways to build 22.5-degree corners for a face frame for an inside corner cabinet.. March 27, 2012

I am a fairly experienced cabinetmaker but have never built a corner cabinet. What is the best way to clamp the two 22.5 degree angles to make the front 45 degree angle on the front face frame? Do spring clamps work? Band clamps? Tape and fold?

Forum Responses
(Cabinetmaking Forum)
From contributor M:
Some of the guys here do it the way you are talking about, but I think my way is easier. I rip my stiles on a 45 degree angle, 2'' wide on the short side, which is the front that you see. The rails are 13'' long (which makes a 24x24 corner cabinet). I then mill a 1/2'' groove on a 45 in the back of the stiles to receive the ply sides.

So basically you have a face frame with 45 degree stiles - no clamping 22.5 degree pieces together. The cabinets that mate up to the corner cabinet are done square and they will match up perfectly. Also I made a sled on a 45 that I cut the floor, roof and shelves on and it works great and I've used it for years. The way I do it is the way most cabinetmakers do it.

From contributor D:
I use blocks band sawn to fit over the face frame thickness, but cut the slot at 22 1/2 degrees so a clamp will be square to it when clamping the opposing side or ends. You can open or close the face of the joint you want tight by skewing the clamps. I keep a drawer full of the blocks.

From contributor J:
Do you use pocket hole joinery? If so, try this. Cut your face frame edges to 45, leave the cab side at 90, and pocket screw through the sides into the face frame with 1" screws. The pocket holes can't be seen on the inside of a corner cabinet and it totally eliminates the need for clamping. When you're finished, plane the points of the 45 degree cuts flush to the side with a block plane. This also gives you a perfect looking miter joint, as the joint is actually not on the miter.

From the original questioner:
Thanks for your responses. This is going to be a corner TV stand and the sides will also be made out of solid. It will be six sided, counting the spine being squared off. After reading what you suggested, I am still thinking tape and miterfolded 22.5's will be the quickest and easiest in this case.

If you 45 the face frame and butt the side, you get the joint line and then another line in an eighth or so, right? This is undesirable to me for a piece of furniture.

Contributor D, I am having a hard time picturing the clamps you describe.

From contributor J:
I wouldn't consider this joint undesirable in the least. I use them exclusively on high end custom kitchens and furniture. In fact, if you can get a joint as clean as this making two 22.5 degree cuts and then clamping them together, I would like to see it. I don't understand why anyone would fuss with trying to clamp this joint and expect to get a super tight miter.

From contributor D:

Click here for higher quality, full size image

Here is a look at the blocks:

Click here for higher quality, full size image

From contributor M:
My apologies - I thought you were talking about a 45 degree wall cabinet in a kitchen. The blocks with the clamp looks like a great idea.

From contributor T:
Tape and fold.

From contributor W:
I use pocket screws to attach face frames to cabinet sides. I make the plywood sides 3/8 or so longer, make the face frames 5/16 longer, and pocket screw from the outside of the cabinet into the face frame. Only works if another cabinet butts up to hide the pocket screw holes. You can't pocket screw from the inside - the screws come out the side.

From contributor J:
You can screw them together from the inside if you do it as described above. It's by far the easiest way to put together a 22.5 with a face frame than any other method. Much cleaner look and you never see the holes. Doesn't matter if anything is going to hide them or not.