mortise and tenon joints

[rherald1951]

please excuse the dumb questions....i am learning mortise and tenon joinery and want to know do i add tenon length to overall length of the tenon piece ie a rail in a rail an stile door?  thanks for the help

 

rjherald

[Askland09]

No such thing as a dumb question.

Short answer, it depends on what kind of tenons you plan on using.  If you're using an integral tenon you'll have to factor in the tenon length into the work piece.  For example lets say the total width of the door is 12" and each work piece is 1" in width and you want to sink a tenon 1/2" into each stile.  So each rail will have to be 11" before joinery is cut.

However, if you're using floating tenons you do not need to factor in the extra material for the tenon and your rail would be 10" going of the example above.  Since you'll be adding the extra 1/2" on each side by sinking a 1" tenon 1/2" into the end of the rail on each side.

Hope this helps.

 

[wtnhighlander]

It is a bit wasteful of material, but I often cut the rail stock to the full width of the the door panel. Then use the stiles aligned across each end to mark the tenon shoulders. Next, lay out and excavate the mortises, gauging against the rail width to avoid over-sizing them. Once the mortice is dug out to a reasonable-looking depth, use a marking gauge to capture that depth and transfer it to the tenon, outward from the shoulder. Then saw off the extra, your rails should be a nice fit, no math required.

[Coop]

Right above about no dumb question and both are excellent answers. I might add that it is wise to cut the mortise first and then the tenon and use a scrap piece the same thickness as your door to size the tenon, sneaking up on it until you have a snug fit, then cut the real deal. 

Welcome to the forum and let us know how it comes out. 

[Chet]

Welcome to the forums.  We except all questions.  Back in middle school I had a shop teacher that said "the only dumb question was the one never asked".

[Coop]

I guess I am older than you. We called it jr. high and not middle school in my days! 

[Chestnut]

I usually leave the board long some arbitrary amount. Then take the measurements on the shoulder to shoulder distance and use marks there to set the length between shoulders. I trim the tenons as needed based on the mortise depth.

If this is for cabinet doors i make every dimension a hair large and then trim the door to size after it's glued together.

[Mick S]

Also, don't cut the tenon to the full depth of the mortise. Stop it about 1/32" - 1/16" shy so that the glue being pressed into the mortise will have some place to go. If the joint is really tight, the hydraulic pressure created can force it apart if you don't allow for it.