Corner-Cabinet Face Frame Joints

Corner cabinets pose a tricky face-frame construction problem. Here, cabinetmakers discuss ways to detail the corner joint. August 29, 2005

It seems like we are building a lot of diagonal upper and lower corner cab units. We put a 45 on each outside edge of the face-frame and also on the two side panels. The problem is sliding the side behind the face frame and shooting a 2 inch #16 with glue at an angle through the frame into the side. It is hard to hold and work the edge down as you shoot and have it pull up tight with no gaps. Does anyone have an easier or better approach to our problem?

Forum Responses
(Cabinetmaking Forum)
From contributor B:
I leave my face frames square and 45 my sides. I glue sides to face frame, and shoot 1" 16g brads through the sides into the face frame. It is fairly easy to hold together this way, and the joint is fairly strong. Add a little filler if needed, and the joint will look great. The joint isn't pretty on the backside because they don't meet right in the back, but you've got to stick your head inside the cabinet to see that. I've built them several ways, and this seems to work the best for me.

From contributor F:
I guess I am the odd man out. I glue two stiles together with a 22.5 degree cut on each stile. Now the face is running straight again on each side to match the continuing run of cabinets on each side. My corner cabinet ends are simply cut to 90 degrees and glued to the back of the continuation ear of the face frame.

From contributor J:
To contributor F: I know how I will do my next set of angled cabs so you won’t be the odd man out. Do you guys clip the back corner?

From contributor F:
I usually clip the back corner of a lazy susan so things can’t get lost behind the turntable, but on a 45 degree sink I run it to the wall. You never know where the plumbing will be and framing keeps getting harder to find.

From contributor T:
To contributor F: I tried this method a while back and I was pretty satisfied with the results. The only downside I felt was clamping the two 22 1/2 degree pieces together. I used glue, painter's tape, and then screwed it together from the outside. How do you do yours?

From contributor F:
To contributor D: Not for strength mind you but for alignment purposes, I use about four or five biscuits to keep the tips of the miters aligned while clamping pressure is applied. It is hard to describe my clamping jigs with words, so I will tell you how I develop them.

Make a full scale layout of the two stiles from the perspective of looking straight down on the end grain, or simply hold the two pieces together with tape and look at the ends. Now look at the line where the two pieces join and you can see where a line of line of clamping pressure would need to be in order to clamp the two together with out them rocking apart. I start with a 1.5" wide or so piece of .25" thick plywood the length of the stiles and then I glue a triangular shaped piece of wood of the correct angles to transmit the clamp pressure directly through the joint on to the .25" plywood. These triangular shaped pieces will be the surface that the clamps jaws will put the pressure on.

In some cases I am able to glue a square cleat to the other edge of the .25" plywood that will hook the inside edges of the stiles to help prevent the jigs from slipping when the clamps are applied. Sometimes I am only able to use a small C clamp at the top and bottom of each sile to hold the jigs in place.

In any case I place them to where there is about 1/8" of wood at the miters tips showing outside of the clamping jig so that the glue squeeze out will not stick to the clamping jigs. If your parts (stiles) are machined well it won’t take so much clamp pressure that the jigs slip as you clamp the joint closed.

Keep in mind that I glue these joints together while working on the face frame alone. In other words, after the joints are glued up and the jigs are removed and the dried glue squeeze out has been scraped off, I then attach the face frame to the cabinet’s carcass. Also, I glue up the center section of the faceframe (I make my faceframes with dowells and clamps) together before I saw the 22.5 degree miters on its edges. If you need to clamp your face frames, this method is easier than having to apply clamp pressure to an already mitered stile.

I like to saw my bevels with the saw blade buried in an auxiliary fence type table saw setup. This way, once the saws fence and blade height are set correctly for the face frames stock thickness, all of the parts (both edges of the face frames center section and also the two extra stiles or ears can be beveled with the same saw setting. I make this setup so that the stiles are at finished width and the miter is sawn right to the edge and no dimension is removed from the long side of the miters.

From contributor N:
I do a fair amount of full height corner cabinets. I keep one fairly good rip blade reserved to cut the 22 1/2 degree angles. I try to miter fold each edge and I lay the two pieces to be glued side by side, apply packaging tape across the seam, apply glue and then fold it up. Sometimes, if I'm lucky, no clamps are needed. But when I need them, I make a few clamping cauls along the lines of what Contributor F suggested, works great.

From contributor T:
Good information Contributor F and Contributor T. I did 26 angled cabinets this way last summer and like I said, I was pretty satisfied with the results. I thought about making some type of clamping fixture, but just couldn't come up with anything that made sense to me. The tape, glue and screws worked okay, and I wondered about using biscuits, next time I'll try that. I made the stiles first, then pocket screwed the rails together and that part worked fine. Doing them this way really made mounting them to the cabinet a piece of cake.

From contributor F:
To contributor T: Since you join your face frames with pocket screws, it seems to me that if you used the biscuits to keep the parts aligned and then screwed the mitered stiles together on the long point side (which will be the back side of the face frame) you might not need any clamping. It is good to know the other technique in case you ever need to make an angled door or the like that will be seen on both sides.

From contributor T:
Yes, I think you're right on Contributor F. The only problem I really had was keeping the alignment while the glue was setting up. I believe you've solved that problem with the biscuits, I'm anxious to try it now, I think it will make it much easier.

From contributor A:
To the original questioner: Why are you nailing your face frame to the module? I have been experimenting with corner cabinets, and I have finally found a good method. Set up your table saw with a dado blade that will cut out approximately 3/4". Next, set your saw tilt at 45 degrees. When you run your stiles through, make sure that there is at least 1/4" of wood left on the outside edge.

In other words, if you are utilizing 1-1/2" stiles for your corner cabinet, set the fence of your saw to approximately 1-1/4". After you have cut both stiles, remove the dado blade and insert your saw blade. Now cut the outer edge of both stiles at a 45 degree angle. You may have to adjust your fence, but the idea is to have at least 1/4" of outer edge stile that will ride against your side partisans.

This will allow you to build a corner module with square sides, as the roof-top dado cut will set flush against the front of the sides and shelves, and the outer edge 45 degree cut will join perfectly with the cabinets at both sides.

There is no need to nail. Before inserting the top and bottom sections, pocket hole the pieces. After the face-frame is attached, lay the module face down, and let the cabinet's own weight secure the face frame to the front of the sides.

From contributor H:
We do a lot of 45 degree corner cabs, our method is a little different. We start off by cutting a "birds beak" into one edge of each 2 1/2" stile, set the saw to 45 degrees about 7/16" high. Run each stile through twice (face up and face down), and save the long triangle waste. Return the blade to vertical, turn the bird’s beak towards the fence and rip to 2", and finally tack the waste back into the v-groove so the sharp edges are protected and then assemble the frame (this piece is removed on the job for assembling).

Our panel sides are 23" deep with a 45 degree cut one front (frame) edge. We glue and staple through the angle from inside into the back of frame, this securely attaches the frame and eliminates the need to face nail. We make sure cabinets adjacent to the corner are built with a style that is 1/2" wider than normal, when they are joined with the corner all stiles look like a 2" stile.

Now on the job, after tapping out both waste pieces, positioning and leveling the cabs, pre-drill through the corner cab stiles as if it was a normal cabinet and screw to each adjacent cab. The major advantage of this method is that all the stiles in the corner are virtually seamless when the screws are drawn tight. Nearly all custom shops in my area of Connecticut use this or some small variation of this method with out exception, it works remarkably well and is a lot easier to manufacture than my post makes it seem

From contributor T:
To contributor F: How wide are you cutting your stiles? When I did mine, I decided the next time I do them I'd make the outside one a little narrower.

From contributor F:
My stile width varies from job to job, but basically 2". Sometimes I split the one that straightens the run back from 45 degrees and use biscuits to join with mating halves on the next cabinets in the runs. You know, after gluing and screwing at installation time they look like a single 2" stile.