First Door - M&T questions

Hello all!

Building a (sliding) door for a family member that had a somewhat specific preference. Not 100% sure it is the most fundamental design, but I think it's close enough to work.

Would be a one-panel, all-Sapele door. 8/4 for the rails & stiles, with a 4/4 panel. Door outer dimensions are 85"x36". Rails and stiles are both just over 6" wide. She doesn't want the raised panel look, and I figured that since the rails/stiles are so thick I could make the dado wide enough to accept the full panel thickness.

Where I'm getting hung up is exactly how to handle the dado for the panel with the M&T connections. Should I run the dado the full length of the stiles, then do a haunched tenon? I wasn't sure if the depth of the dado (1/2"?) would weaken the M&T connection. I have a good router but figure I would need to get out the chisels to get the mortise deep enough to be effective.

I know that variations of this have been done a million times, but I've been having trouble getting the right picture in my head to make this work. I have a good TS/dado stack and router, but no drill press or mortiser.

-Micah

Quote:

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Originally Posted by Micah Puscheck

Should I run the dado the full length of the stiles, then do a haunched tenon?
-Micah

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Yes. I go 2 1/2" deep including the 1/2" deep groove. A 3/4" panel centered in a 1 3/4" door will be ok. Do the math to size the panel correctly considering seasonal movement.

Quote:

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Originally Posted by Kevin Jenness

Yes. I go 2 1/2" deep including the 1/2" deep groove. A 3/4" panel centered in a 1 3/4" door will be ok. Do the math to size the panel correctly considering seasonal movement.

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Thank you Kevin, that's very helpful!

A guideline for M&T work is to make the tenon 1/3 the thickness of the stock. That puts it close to 5/8", or 9/16". Or even 1/2" for a nice, easy to use number.

We always built doors where the tenon thickness was the same as the panel thickness/plow. For 1-3/4" doors, most were 1/2", but could go up to 1" if we needed to. This greatly simplifies things. You do not mention if the door will have square edges or be coped and stuck. The following shows a coped and stuck rail and stuck stile, but more importantly, the 1/2" thick tenon and plow.
Attachment 494060If you route your mortises with a 1/2" spiral bit, they will come out a bit over 1/2" - maybe .580 or so. Make the tenons to fit the mortises. 2-1/2" is a good depth. Heck, it is a great depth - for square edge doors. If coped and stuck, you could dial that depth back to 1-1/2" or so. We built thousands of doors with 1-1/2" long tenons, plus the cope. Never had one come apart.

Drawing from my book "Small Shop Production of Custom Wood Doors" by David R Sochar available at www.acornwoodworks.com/book (autographed) or Amazon or any online dealer.

Quote:

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Originally Posted by David Sochar

A guideline for M&T work is to make the tenon 1/3 the thickness of the stock. That puts it close to 5/8", or 9/16". Or even 1/2" for a nice, easy to use number.

We always built doors where the tenon thickness was the same as the panel thickness/plow. For 1-3/4" doors, most were 1/2", but could go up to 1" if we needed to. This greatly simplifies things. You do not mention if the door will have square edges or be coped and stuck. The following shows a coped and stuck rail and stuck stile, but more importantly, the 1/2" thick tenon and plow.
Attachment 494060If you route your mortises with a 1/2" spiral bit, they will come out a bit over 1/2" - maybe .580 or so. Make the tenons to fit the mortises. 2-1/2" is a good depth. Heck, it is a great depth - for square edge doors. If coped and stuck, you could dial that depth back to 1-1/2" or so. We built thousands of doors with 1-1/2" long tenons, plus the cope. Never had one come apart.

Drawing from my book "Small Shop Production of Custom Wood Doors" by David R Sochar available at www.acornwoodworks.com/book (autographed) or Amazon or any online dealer.

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That's a good reminder about tenon thickness, but it is somewhat flexible. I build doors with spline tenons and the spline thickness is independent of the groove width - I usually use 5/8" stock for 1 3/4" doors. To use a 1/2" tenon/groove and thicker panel, rabbet the panel.

David's book is invaluable for anyone interested in the subject.

Highly recommend David's book. Years of experience documented in an easy reading style...a great reference!

The plan is for the door to have square edges. To stay around those guidelines for the mortise (if the groove is the same width) would mean planing down the panel a bit more or rabbeting the panel. I think I'd rather avoid the latter as I believe that would have to be visible (unless covered with trim I suppose).

I should be able to get to about 2.5" on the mortise.