Mitered Cabinet Doors

[Scott Cenicola]

I am matching 3 cabinet doors to an existing kitchen. The stiles and rails are mitered. I have a mini biscuit joiner that I would use to strengthen the joint, but it just broke on me. The question is, is glue alone strong enought for this type of joint? I don't have a doweling jig, but i could just add a dowel or two in each corner. I was considering replacing the biscuit joiner, but I just don't use it often. I often read here that biscuits and dowels are more for alignment than strength, but with such little glue surface for the mitered joints l wanted to get opinions. TIA.

[Lee Schierer]

When gluing mitered joints you are essentially gluing an end grain joint. Glue starvation is the most likely cause for joint failure. Apply a wet coating of glue to both sides of each joint. For added strength you could use pocket hole screws from the back and then fill the pockets with plugs. Make sure your 45's are precise so that all four corners close up properly. Any gaps will weaken the joint.

[Vince Shriver]

Can you cut a slot into the length of the two mating mitered ends for a spline?

[Robert Engel]

Make a clamping jig, glue, countersink screws from top and bottom and plugs. It will work fine.

[George Bokros]

I just built some doors and drawers that were mitered. MLCS sells a slot cutter and round biscuits for this purpose which is what I used for the doors. For the drawer front rails and stiles I made a jig to mount my PC biscuit joiner to and used face frame biscuits since the rail and stile material was narrower that that used for the doors.

[Jim Becker]

One method to create these and still have an extremely strong joint is to do a lapped miter joint. It takes some work, but you get the look of the miter and about the strongest joint you can do in a small place at the same time.

[John TenEyck]

I made a few mitered doors using biscuits and I now see cracks at some of those joints. If I build more of them I will use loose tenons at the joints. A spline would be a close approximation if you can't cut mortises on angled parts. You could even glue them up without reinforcement and then add a spline from the outside afterwards, either matching or contrasting. I've even seen people drill a hole across the back of the glued up joint with a large Forstner bit and glue in a plug, sort of a round Dutchman. In any case, I'd use some sort of reinforcement.

John

[Scott Cenicola]

It's clear that reinforcement is needed. I liked adding a spline idea, until I read half lap miter. That may be the way I go, I'll have to do some test cuts. Thanks for the ideas

[Andy Giddings]

+1 on the spline - easy to do

[lowell holmes]

Many of us abandoned biscuit joints shortly after trying them (many years ago).

I would go with half laps or splines.

[Edwin Santos]

Many of us abandoned biscuit joints shortly after trying them (many years ago).

I would go with half laps or splines.

And then there are others among us who could not live without their biscuit joiners and the strong, accurate, efficient results they get with them when used properly.

Regarding the OP's issue, if you have a way of making the cut, a spline would be a fine solution. I might glue up using a first coat of glue size to deal with the endgrain starvation issue. Once glued, then you could reinforce with a dowel or two without a doweling jig. You could countersink the dowel and plug the hole with the same wood as the frame or a contrasting wood like someone above who suggested countersunk screws. Or you could cut the dowel off flush and proceed to finishing. The answer might depend on what tools you have available.

[lowell holmes]

I used biscuits for years, but grew disenchanted with them. I found while they aided in alignment, the joints were subject to failure if subjected to forces not normally encountered.
I find mortise and tenon joints to be more substantial and less likely to fail.

Do not assume that because someone does not like the joint, they don't know how to make them.

[Edwin Santos]

I used biscuits for years, but grew disenchanted with them. I found while they aided in alignment, the joints were subject to failure if subjected to forces not normally encountered.
I find mortise and tenon joints to be more substantial and less likely to fail.

Do not assume that because someone does not like the joint, they don't know how to make them.

Lowell,

I did not say (or mean to say) you don't know how to make biscuit joints or any joints for that matter. I was only offering the testimonial that I have enjoyed strong, accurate and efficient results when I use biscuits properly. I believe I've cut at least 2000 biscuit joints in various applications over the course of 20 some years. The only single failure I have ever seen was early on due to improper application and technique on my part, learning curve you might say.

It has been my experience that biscuit joinery is an excellent technique to keep in a woodworker's arsenal to go along with many other joinery techniques. It's not a case of "better than" or "worse than" another type of joinery. It truly depends on the circumstances and the application. For example, I agree with you, mortise and tenon joints are strong, but there are circumstances when they are not appropriate or realistic despite their strength.

Regarding the OP's question, several responses, including mine, have recommending using a spline. To me a biscuit is a form of spline.

[Art Mann]

Dowels are not just for alignment. They will strengthen a joint tremendously. To be successful, however, you need a very good doweling jig like the JessEm or Dowelmax. The inexpensive self centering type is not good enough in my opinion. It may not be worth it to you for just one project. I think the spline idea is a good one and it is a little less challenging to cut than the half lap miter.

[Martin Wasner]

If you've wanted a domino, this would be an excellent application for one on a small scale.

[lowell holmes]

Just for the record,
I have a doweling jig, mortice pal, and biscuit joiner. I use all of them on occasion, but favor the mortice pal. In chair building, I need strength and alignment. Biscuits might be used in cabinet doors, but I tend to use mortice and tenon.

I also will use hand cut dove tails.

[mreza Salav]

Domino is excellent (but expensive) option here. Spline is good too but if you use solid wood for the spline (instead of ply) make sure the orientation of the grain is perpendicular to the length of the spline (or else it is very weak).

[Scott Cenicola]

If you've wanted a domino, this would be an excellent application for one on a small scale.

That"s a great idea. But I can't swing it. It's a shame though, because I want to get one for chairs I would like to make down the road.

Please excuse my ignorance, but isn't a domino a thick biscuit? I read all the time how great they are. Is the thickness of the insert the reason for the significant quality increase? I do umderstand the increased precision of Festool tools.

[johnny means]

One trick I've used in a pinch is to make a half thickness butt jointed frame then glue a second mitered frame on top. The result is basically a quick and dirty version of a half-lap joint. All the strength without the set-up.

[Jim Becker]

Dowels and Dominos are both "loose tenons". :) Biscuits are somewhat the same at a base level if you think about it. In all cases, you're cutting a recess in the wood and putting a piece of something into the recess to help align and reinforce the joint while gluing it together.

[Jim Becker]

One trick I've used in a pinch is to make a half thickness butt jointed frame then glue a second mitered frame on top. The result is basically a quick and dirty version of a half-lap joint. All the strength without the set-up.

That's actually a very interesting way to do this and if you are using the same species for the layers with identical grain direction. I would propose that if you use three layers, you'd get an even stronger joint because it would be similar to a bridle joint in most respects. Of course, you need to press it together well. Alternatively do your butt joints with pocket screws and hide said pocket screws with the mitered overlay. So many ways to do this!

[Rick Moyer]

Domino is excellent (but expensive) option here. Spline is good too but if you use solid wood for the spline (instead of ply) make sure the orientation of the grain is perpendicular to the length of the spline (or else it is very weak).
Just to be clear, don't you mean "parallel"? The grain should run longitudinally, i.e., across the joint?

[mreza Salav]

Just to be clear, don't you mean "parallel"? The grain should run longitudinally, i.e., across the joint?

Nope, I meant what I wrote. For a long spline, say 1" wide and 3" long and 3/16" thick which goes 1/2" deep into each miter edge, is better to have its grain running perpendicular to
its length (which means perpendicular to the edge of the joint). The spline is likely to break along it's long edge and you want the grain be perpendicular to that.
It will act like a shallow but wide tenon this way....

[Edwin Santos]

Nope, I meant what I wrote. For a long spline, say 1" wide and 3" long and 3/16" thick which goes 1/2" deep into each miter edge, is better to have its grain running perpendicular to
its length (which means perpendicular to the edge of the joint). The spline is likely to break along it's long edge and you want the grain be perpendicular to that.
It will act like a shallow but wide tenon this way....

Would you consider keeping the spline thickness to 1/8" or less to eliminate the variable of wood movement?
It's hard to imagine wood movement in something as small as a spline, but any movement at all is enough to undermine the spline's purpose in life and turn it from a friend into a troublemaker.
The spline doesn't need to be particularly thick to do its job of holding the joint together. Many people cut the slot on a table saw so I usually see miter splines the thickness of the saw kerf.

[Sam Murdoch]

Lots of good suggestion already so I won't repeat, rather I offer a far less craftsmanship alternative - long finish screws. Two in from the stiles one in from the rails. Of course make certain your joint when glued up is tight and clamp a sandwich of wood strips top and bottom face (that still allow you a peak at the joint. These strips will insure that the joint doesn't move as you set the screws. Even with finish screws (I really like GRKs) you should pre bore a pilot hole and for hard wood also slightly enlarge the hole where the screw head will land as the screw head could mushroom or split your wood.

NOW - I would never build cabinet doors this way (I would not typically build mitered corners doors or panels in any event) but if I were repairing one or two that had loose corners that were otherwise solid, or as in this case making up a few doors to match without other tools available, this might be a viable alternative.

[Scott Cenicola]

Thanks again for all the ideas. I'm leaning toward the half lap miters. I made myself a nice miter sled for my table saw last night. Gonna do a few test runs over the weekend.