Replacing Short Tenons with Dominos on an Entry Door.

[derek labian]

I was considering cutting 1/2" grooves in the rails to accept panels, glass, and the short tenons from the styles, and cutting through the short tenons & groove with 14mm 5" Dominos. My goal is to get away from making full size tenons on the styles and using the HCM or Router on the rails. The material is white oak, and the door is 1 3/4" thick.

Will anyone with more experience than me let me know if this will work fine, or it's a bad idea?

[Richard Coers]

I would not even consider just stub tenons on a door that heavy. I have a lot of door slammers in my family, and that would load a stub tenon to the point of failure. Edit; It doesn't have to be either or, you can have the stub tenons AND Dominoes.

[Mark Bolton]

or it's a bad idea?

You already know what the answer is.

[John TenEyck]

Yes, add the Dominos right thru the stub tenons. And use at least two in the top and lock rails and 3 in the bottom rail if possible.

John

[Kevin Jenness]

Yes, that will work. I have made many doors with stub tenons plus 5" long spline tenons. Some will choke on the idea of using anything but integral tenons and I will concede that they are better in principle, but 35 years of experience makes me think well fitted and glued spline tenons are good enough.

Use as many Dominos as will reasonably fit in the rails. Cut the mortises in the rails before coping, that will give you better bearing for the fence and sighting the center mark. If you have a center stile, pre-assemble it and the rails so you can accurately mark the the mortise locations on the outer stiles.

[Joe Calhoon]

Yes, that will work. I have made many doors with stub tenons plus 5" long spline tenons. Some will choke on the idea of using anything but integral tenons and I will concede that they are better in principle, but 35 years of experience makes me think well fitted and glued spline tenons are good enough. .

I agree totally with this statement Kevin. The stub tenon needs to be reinforced. Loose tenon, Domino or dowel all work if carefully crafted.
Working smart means using the machines you have on hand to achieve the best joinery possible with those machines. Especially if you are in the business.

[Jim Becker]

14mm Dominos are darn strong and used in multiples as well as long lengths can do the job, IMHO. I'd probably still do the shallow cope and stick M&T and it will not interfere with using the Dominos for a heavy door. This is my opinion and I wouldn't hesitate to build a door using this method.

[scott lipscomb]

I built a large entry door with a single glass panel and fit eight 14mm dominoes in each lower corner and 6 each in the upper corners, ran them full 2 3/4" depth and the feeling I got when gluing the door up was very good. I have build a fair number of doors, windows, and vehicle gates over the years using a whole bunch of different kinds of joints at the corners and my feeling, lately, is that using the domino is kind of cheating, but that they are very, very strong.

I know that some feel that traditional M/T joints are stronger, but I am not so sure. The long grain to long grain side is very unlikely to fail in the slip tenon, so the side in question is the long to side grain side. The upside to the domino is that it is easy to make a joint with a whole bunch of tenons, instead of just one or two, which may or may not increase the glue surface, but I think, more important (and this just is just my guess) will be less likely to fail due to wood movement.

But hey, maybe I am just telling myself this, because the domino is so dang fast. Its an amazing tool.

[David Kumm]

Dominos will be much stronger than dowels and 2.5" into each side is acceptable. I generally don't bother with the center rail of a 6 panel although I had someone fall against a door and the stub cracked so you could argue dominos there might be better. Won't help against sag like the others, but may if the bad guys try to break in. Dave

[derek labian]

you can have the stub tenons AND Dominoes.

Hi Richard, thats what I meant. Thank you!

[derek labian]

Cut the mortises in the rails before coping

Thank you, good idea!

[derek labian]

Yes, add the Dominos right thru the stub tenons. And use at least two in the top and lock rails and 3 in the bottom rail if possible.

John

Thank you, glad to hear some confirmation.

[derek labian]

I built a large entry door with a single glass panel and fit eight 14mm dominoes in each lower corner and 6 each in the upper corners, ran them full 2 3/4" depth and the feeling I got when gluing the door up was very good. I have build a fair number of doors, windows, and vehicle gates over the years using a whole bunch of different kinds of joints at the corners and my feeling, lately, is that using the domino is kind of cheating, but that they are very, very strong.

I know that some feel that traditional M/T joints are stronger, but I am not so sure. The long grain to long grain side is very unlikely to fail in the slip tenon, so the side in question is the long to side grain side. The upside to the domino is that it is easy to make a joint with a whole bunch of tenons, instead of just one or two, which may or may not increase the glue surface, but I think, more important (and this just is just my guess) will be less likely to fail due to wood movement.

But hey, maybe I am just telling myself this, because the domino is so dang fast. Its an amazing tool.

I agree; I have a HCM and I just got a Domino XL. I've been watching videos of building both with long tenons and Dominos. I like the T&G (short tenon) + Domino concept but couldn't find anyone doing it. Thanks for the confirmation.

Do you think I should buy a 14mm cutter or just do extra 12mm?

[Jim Becker]

Do you think I should buy a 14mm cutter or just do extra 12mm?

For an entry or passage door, no question I'd use the stronger, stouter 14mm Domino stock. (I buy the 750mm long sticks as it's less expensive than pre-cut for sure)

[Warren Lake]

Here is a pro shop doing big coin stuff I sent Joe a while back and he said CNC machine. I dont know why they choose this over mortise and tennon. Big head one shot and other options, through tennon, draw bore, wedge tennon, pegged etc. there was a comparison you tube someone posted and I cant remember but I thought it wasnt fair as the size they used to test the tennon was smaller than it would be on a door.

Old guys did mortise and tennon, it was time proven, Dowels were their second choice before the gizmo tool revolution.

If you look at this there is no consideration for bottom rail movement, Usually 9" or more. I dont know how they get around that. At least with a mortise and tennon the tennon is cut and relieved. Get that quarter sawn and stave core veneer over top less movement

451100

[Peter Kelly]

14mm x 140mm Dominoes for entry doors.

[scott lipscomb]

14mm is a nice size. I buy the long stock in Sipo. Pricey, but good value at the end of the day (or decade).

[Jim Dwight]

I like my domino XL and have used the 14mm cutter on bed frames and a crib so far. With both, I wanted a wider tenon than a normal domino. So I plunged the machine multiple times about 1/2 inch apart to make a longer mortise. Then I made a slip tenon to fit the mortise. So far the only domino tenons I've used made by Festool is some 12mm ones that the previous owner of my machine sent with the tool. So I make my tenon stock. I like to keep 3 foot sticks on hand made from scrap and it is certainly handier to just cut some of that to length. But I think it is stronger to use a wider tenon. But not by a lot as long as you fill up the space available with the narrower tenons.

14mm is pretty close to the pretty stand 1/3 the thickness rule of thumb for tenons in a 1 3/4 inch door frame. 12mm would be a little on the thin side.

I can cut tenons that work using only my table saw (and my router table to round over the edge) but I get better tenon stock if I cut it a little oversize and then use the planner to nibble it to the final thickness. I get a little more thickness variation if I just use the table saw. But probably not enough to affect strength.

[Thomas McCurnin]

Dowels, Dominoes, Mortise and Tenon: I think structurally they’re equal, so it comes down to your gear and the ease of installation.

see this video on strength tests: https://youtube.com/watch?v=_vgAeGCATgM&feature=share

That said, I can’t afford Festool, and I don’t have a Dowelmax, so I tend to use M&T.

[Warren Lake]

Thom here is the one I think you posted before and thanks for posting it Might have been part one im just seeing this part 2 now I didnt agree with one aspect forgotten now on the one you posted likely the tennon being over thickness.

No close up you dont see the failures, yes it failed but what failed? the damage has info. Mentioned is the well known people who did a test and he found things wrong with the test. Hes not got a haunch there and that would be on there from the slot for the panel that runs right through. Then more material on the tennon would make it stronger, good job there. Guess the dowel would have it as well. Still think it should be as it would be in a door.

https://www.youtube.com/watch?v=WoOEwEuB1ag

[derek labian]

In the end I went with 140mm SIPO dominos. So far so good and ultimately much easier.

I also ended up using SIPO and White Oak dominos for the muntins and mullions. That has also worked out very well, thus far considering how small the dominos were.

[Jim Dwight]

I think your plan will work but I would use larger loose tenons and probably make them of the same wood as the door. It is simple to do overlapping cuts with the domino to make a bigger slot mortise. I figure out what size tenon fits considering the weight and the available space in the rail and stile and then cut that size mortise. Then I rough out some tenon stock on my table saw and use my planner to get it to final thickness. A roundover bit in the router table and I am done.

I think the only "issue" with domino mortise and tenon joints comes about when we limit ourselves to the pre-made tenons. When they are smaller than appropriate, the project may suffer.

Like Jim Becker I make up some 3 foot sticks to have on hand but I only use them when they seem appropriate for what I'm building. For an entry door, I would make larger ones for sure.