Gut check on domino placement/selection

[Sam Shankar]

I'm making a straightforward shaker writing desk for my brother. Basically a 4'x2' leg/apron table with a drawer. I originally intended to use traditional pinned M&T joinery for the leg-apron joints, but then made a layout mistake that leaves me reaching for the domino joiner instead. I know dominos are not as strong as M&T joints, but I'm trying to get as much strength as I can in there. Anyone think I can get away with three 8x50 dominos in this joint? The apron stock is 4.25" x 7/8" thick. The legs are 1 5/8" square.

You could alternatively tell me that two dominos are enough. Or that I should use the domino to cut a single wide mortise and make matching wide loose tenons of my own.

You can also tell me I'm a bonehead for forgetting to include the tenon length when I cut the aprons to length.

leg apron domino placement.jpg

[Jamie Buxton]

First choice: make your own wide “domino”.
Second choice: three dominos.

[Jim Dwight]

I agree with Jaime but had to ask, do you have a 500? Is that why you are only going 1 inch deep? If so, then that is a limitation but I suspect it will work, especially if you spend a few minutes and make some tenon stock. I cut it to rough thickness and finished width on the table saw and then sneak up on finished thickness with my planner. Then finally I round over the edges on the router table. Doesn't take long. I've never purchased a Festool tenon. So I've made a bunch. I keep 3 foot sticks on hand but if I need something wider I just make it out of scrap.

[Sam Shankar]

...do you have a 500? Is that why you are only going 1 inch deep?

Yes, I have a 500. Not sure how much deeper I would go with a 1 5/8 leg though.

[Myles Moran]

That layout makes sense to me. If I was cutting a tenon for it, I'd have it be 3/8"X1"x3.25", and your 3 dominos get you nice and close to that. I've done tons of 1" tenons into 1.5" leg stock, so the length you're working with doesn't seem short to me at all.

You can also tell me I'm a bonehead for forgetting to include the tenon length when I cut the aprons to length.

If that's the case I'd guess the majority of people who have made a mortise and tenon joint would be a bonehead. Luckily it's an incredibly easy mistake to hide.

[Sam Shankar]

Luckily it's an incredibly easy mistake to hide.

You mean with a loose tenon? Or with a smaller table? (Or do you have another trick I need to learn!)

[Myles Moran]

Loose tenon is the easiest fix by far (and can still be "pinned") I've also repurposed a miscut rear rail to be a drawer front (or cut in half to be side rail, but that one only works if you've cut the pieces in the correct order and the design works for that.

[Jim Becker]

If that's the case I'd guess the majority of people who have made a mortise and tenon joint would be a bonehead. Luckily it's an incredibly easy mistake to hide.

Yup...loose tenon (which includes Domino) is about the best way to make up for that kind of thing when remaking the part would be difficult due to material or other reasons.

[Sam Shankar]

Loose tenon is the easiest fix by far (and can still be "pinned")

I had planned on the pins being a design element, so was really annoyed when I cornered myself into having to do a domino/loose tenon. But you're right: I can pin loose tenons too...on both sides! Twice the pins, twice the design value? (Anyone ever pin dominos?)

[Jamie Buxton]

.. (Anyone ever pin dominos?)

Yes. It works.

[Jim Becker]

I had planned on the pins being a design element, so was really annoyed when I cornered myself into having to do a domino/loose tenon. But you're right: I can pin loose tenons too...on both sides! Twice the pins, twice the design value? (Anyone ever pin dominos?)

You can also just put in the pins where you want them as a decorative element, too...they don't have to pass through the Dominos unless there is some structural reason you want to do that. IE...hide the fact that you took plan B.

[Sam Shankar]

You can also just put in the pins where you want them as a decorative element, too...

Wait, I thought cosmetic joinery was a sure way to compromise joint strength!

[Jim Becker]

Wait, I thought cosmetic joinery was a sure way to compromise joint strength!

If you feel the joinery needs the pins for strength, then put them in so they are used that way. If you just want the look, put them where the appearance will be best. Of course, Murphy might want a say in this as I think you are alluding to...

[Jim Dwight]

I would go 1 1/4 or even 1 1/2 deep in a 1 5/8 leg and probably deeper in the apron where you can. But I think 1 inch will probably work fine. I tried a #20 biscuit once and that failed. So now I like to make the attachment as big as possible. When I need strength, I also put 8mm tenons in 3/4 stock too. By the 1/3 rule, 6mm is closer but I saw some tests of wider tenons, I think it was by Matthias Wendel (sp?) and he got stronger joints with a tenon closer to 1/2 the material thickness. So I think it is better to go a little over 1/3 rather than slightly under.

[Thomas Crawford]

I made a similar mistake on a similar table. I was making two at the same time. One ended up with traditional M&T and the other with 2 dominos. I could not tell the difference structurally (no extra racking or anything). I wouldn't sit or stand on either one.

Remember once the table top is on that is what really finalizes the structure and makes it rigid.