Cabinet End Panels- Splined Miter, Lock Miter, or ??

[Pat Wright]

Hello,

I'm in the final stages of a kitchen cabinet build, and would like some input on integrated end panels for paint grade work. I have all boxes, face frames, and end panels built.

On these cabinets, I'm shooting for no reveal between the face frame and end panels. Both are 3/4" thick hard maple. While originally I was going to butt the end panel into the back of the face frame, I realize that differential expansion between the edge grain of face frame and face grain of end panel will likely result in a hairline crack in the finish over time, or at least telegraph through the finish, and I just can't bring myself to do it.

I've searched here and read many threads on the issue of long miters, and have some experience with them on stain grade work (like on newel posts) using my lock miter bit. But in this case my parts are already assembled into face frames/end panels, and I can't imagine how I'd keep the parts perfectly against the fence, especially vertically, to use the lock miter method which requires such precision in setup and milling. It seems a 45 miter with spline could be appropriate, and I made up a test joint last night using a hardboard spline which worked out pretty well. Yes, I know I should have figured this out in advance, but really want to avoid re-building these face frames and end panels. The end panels were built 1.25" oversize on width (1/2" scribe on wall side, and 3/4" was going to be ripped off face frame side for butt joint but I haven't done that yet), so they would still work with a miter joint.

So, my questions:

1. Splined miter OK in this situation, using 1/8" hardboard spline? I typically keep the spline about 1/8" from the heel of the joint, but then that leaves a much larger area at the toe which is just glued compared to the lock miter. Will I need to worry about the toe joint opening up? Seems if I burnish the sharp edge then sand a small radius, the glue line is almost invisible.
2. I'm having some issues getting a long, perfect 45 on the table saw in this hard maple. I've tried hogging out most of the cut with a think kerf rip, then using my full kerf glue line rip for final sizing, which seems to work OK. I think I'm getting some deflection in my insert with downward pressure, as I don't have a stiff zero clearance insert setup for 45 deg cuts (though I could make one I guess). Any suggestions? Longest piece is 37" for upper cabinets.
3. I don't currently have a large enough 45 deg chamfer bit for my router table but had thought maybe this would be easier to get a precise 45? I could cut 95% of the miter material away on the table saw which wouldn't require absolute precision, then just use the router table for final cleanup. Any thoughts? I'm not at all opposed to spending the $80 on the bit, but not sure if it'd be easier. I had planned to double sided tape a guide board on the top, so that it protects the knife edge against the outfeed side of the fence allowing me to put enough sideways pressure on it. I've done this with great success on lock miters.
4. Finally, should I just attempt the lock miter? I could run the face frame flat on the table, then run the panels vertically. Still makes me nervous... and I didn't take as much care in keeping the stock as precise in thickness as I would if I planned this method from the outset. Just for example, some of the face frames may be .755" thickness, while the end panel may be .740" or something. If I had planned this from the beginning I would have used stock from the same milling session for the joints that are lock mitered. Furthermore, I wouldn't be able to get any test cuts with the actual stock, and while I can usually get the bit set up pretty quickly I know how bad an ill fitting lock miter can look. Seems risky.
5. Any other ideas? I have a fairly well equipped shop (2HP cabinet saw, 6" jointer w/ helical head, 2-1/4 hp table mounted router, track saw).

Would appreciate any input you have. Been reading these forums for a long time and have gotten some great ideas, but I feel stuck here on this big project. So close to being done, yet this one remaining issue to solve!

Thanks,
Pat

[John TenEyck]

I would stick with your initial idea and use a butt joint between the end panel against the back of the face frame. Use a spline or biscuits, etc. for alignment if you like. After the glue is dry I'd route the faceframe flush with the end panel, and then run a 45 deg router bit about 3/32" deep in the joint. Alternatively, you could route a small rabbet on the edge of the end panel prior to glue up. Either creates a shadow line to deal with any cracks in the pain or misalignment in the joint.

John

[Kevin Jenness]

A simple miterfold joint will do what you want. It does require accurate 45 degree straight bevels (or a scosh under) on the two pieces. If the face frame is not yet applied to the cabinet, lay it and the return panel flat on the bench with the miter tips butted together and apply 2" clear packing tape the length of the joint. Burnish it down with a softened-edge block. Stand the pieces up, apply glue and fold them closed. You can clamp them to a square gusset to ensure a 90 degree corner. If the face frame is on the box, getting the pieces aligned and taped together is a little more difficult but the procedure is basically the same. Splines make for clamping complications and add no strength to a long grain glue joint. A mitered connection is much more elegant and no harder to do than a butt joint.

I use a sliding table saw to cut the miter on the assembled face frame stile, but you can do it with a large router bit or on your table saw depending on the blade tilt, or with your track saw.

[Richard Coers]

Your entire box is solid 3/4" maple? If not, and the rest of the box is plywood, and you screw it to the wall, that solid end panel is going to shove the face frame off the box come spring time. You'll have more than a little crack at the side and face frame to worry about. That's why a lot of shops just add an end panel that looks like a door using frame and panel.

[Pat Wright]

Hi Guys,

Thanks for the input, I really appreciate it. To answer some of the questions:

I would stick with your initial idea and use a butt joint between the end panel against the back of the face frame. Use a spline or biscuits, etc. for alignment if you like. After the glue is dry I'd route the faceframe flush with the end panel, and then run a 45 deg router bit about 3/32" deep in the joint. Alternatively, you could route a small rabbet on the edge of the end panel prior to glue up. Either creates a shadow line to deal with any cracks in the pain or misalignment in the joint.

This is an interesting thought and I'll keep it in mind. The style of this kitchen is very simple though, with all stiles sized to eliminate fillers, and some cabinets with long face frames over multiple boxes to keep everything neat, simple, and evenly spaced, with basically no seams between cabinets or reveals on anything. This groove may stick out like a sore thumb in this case (though not as much as cracked finish would..). Since the end panels are shaker style, I'd effectively have a groove right in the middle of the end panel stile.

A simple miterfold joint will do what you want. It does require accurate 45 degree straight bevels (or a scosh under) on the two pieces. If the face frame is not yet applied to the cabinet, lay it and the return panel flat on the bench with the miter tips butted together and apply 2" clear packing tape the length of the joint. Burnish it down with a softened-edge block. Stand the pieces up, apply glue and fold them closed. You can clamp them to a square gusset to ensure a 90 degree corner. If the face frame is on the box, getting the pieces aligned and taped together is a little more difficult but the procedure is basically the same. Splines make for clamping complications and add no strength to a long grain glue joint. A mitered connection is much more elegant and no harder to do than a butt joint.

I use a sliding table saw to cut the miter on the assembled face frame stile, but you can do it with a large router bit or on your table saw depending on the blade tilt, or with your track saw.

I've done the miter fold many times on smaller pieces and it works well! So basically you're saying, don't worry about this long miter opening up, even without joint reinforcement? There is a lot of glue area, but it seems quasi-end grain in certain areas when cut on the 45. I guess then it just comes down to making a setup that achieves a perfect miter (router, vs table saw, vs track saw). And to clarify, the face frame is not yet applied to the box, so I'm dealing with flat assemblies.

Your entire box is solid 3/4" maple? If not, and the rest of the box is plywood, and you screw it to the wall, that solid end panel is going to shove the face frame off the box come spring time. You'll have more than a little crack at the side and face frame to worry about. That's why a lot of shops just add an end panel that looks like a door using frame and panel.

I wish I had a picture but I didn't model the end panels in my cabinet model. The boxes are already built, all 3/4" prefinished maple ply, dado'd and glued/screwed together, but face frames not installed to boxes yet. My goal is to have the face frame wrap around to the end panel (which is 5 piece flat panel shaker style- maple rails/stiles with glued 1/4" MDF center panel). Kind of like typically would be done on inset door cabinets (though mine are overlay). If you picture a "right" end panel, that is looking at front of cabinet end panel is on right. I was originally going to make the left stile of the end panel 1.5" wide, so that when butted up to the back of the face frame it visually makes for a 2.25" wide left stile on the end panel. Right stile is currently 2.75", leaving .5" for scribe allowance. Outside corner flows smoothly from face frame to end panel with no reveal. What I'm proposing is miter the right stile of the face frame, and left stile of the end panel, and have a sharp outside corner.

Attached pic shows the face frame extending to the left, which meets the end panel on right butted up to back of FF (where I'd like to miter). In foreground is a section of the sample miter joint with spline that I made on table saw. Hard to tell since it's sitting on my MDF assembly table but you can see the MDF center panel of end panel. Also included a random pic I found via Google which is similar, though my end panel isn't made to look like an inset door but rather just a shaker style panel.

Thanks again,
Pat

FaceFrame.jpg


corner.jpg

[Brad Shipton]

Here is an example of one I built not long ago (end panels were being test fitted). Those are simple miters and I used Lamello tenso connectors to attach together and to the cabinets. My miters had a few minor flaws, but those were fixed easily before finishing. I would not fiddle with a lock miter, but I had quite a few to do.

cnr-01.jpg

[Pat Wright]

Looks really nice Brad! I have 8 joints I need to do this on. Did you just cut that long miter on table saw? Any tips for doing that (i.e. blade, setup, etc)?

[Kevin Jenness]

"There is a lot of glue area, but it seems quasi-end grain in certain areas when cut on the 45."

Assuming your end panel stiles extend top to bottom the bevel surface is 100% long grain. There is no need to "reinforce" the joint with a spline or lock miter, and the tape serves to index the two sides of the joint. One advantage of the miterfold is that it eliminates the need for clamping across the joint.

One way to cut a 45 on your parts is to add a sacrificial fence to your rip fence. Assuming 3/4" panel material, attach the sacrificial layer 11/16"" above the table top, leaving a slot for the waste material to fall free. Set the rip width and raise the blade up into the wood fence so it enters at or a hair below the top of your material. When you run the stock you will be left with a feather edge or a miniscule flat land at the miter tip, and the waste strip will not be trapped between the fence and the blade. This works best with a right tilting blade and an outboard support or helper. It will be difficult with a long face frame, making the track saw perhaps a better alternative. This is a task made easy by a sliding table saw.

[Brad Shipton]

Pat, I used my shaper for a few, but switched to cutting on the slider for most. The face frames were a bit too narrow for the shaper and power feeder. As the parts moved past the infeed fence they had a tendency to rotate a small amount and that led to a few repairs. The slider worked much better since I could rigidly clamp the parts at each end to avoid any movement. I am sure others have a nice fixture for the shaper, but too many times I spend too much time making jigs.

[Jim Becker]

On the joint between the face frame edge and the end panel, when they are flush, some makers use a router bit that puts a little vee-groove right on the joint which hides any potential movement/cracking over time while adding a slight visual interest like a reveal would I'm honestly sorry I didn't do that on the two "end" upper cabinets I put in our kitchen a few years ago because even without cracking it's hard to truly hide that transition between panel and face frame no matter how good your finish is. Rather than hide it, I should have highlighted it.

[Jared Sankovich]

I use a miter fold cut on the TS or a lock miter run on a shaper. If I'm running a lot of ends its on the shaper, if its just a couple the miterfold is just faster.

[Robert Engel]

+1 on Kevin's suggestion re: miterfold. Spline, lock miter not necessary. Lewis on Insider Carpentry has a video on using miter fold to build columns.

Other possibility is what John said, using biscuits, but use a v groove flush trim laminate bit and put a shallow groove in the joint line.