# mortise and tenon fit and glue up



## nbo10 (Jan 26, 2011)

Hi All,
Working on my first set of mortise and tenon joints. I used a plunge router with 3/8" bit for the mortise and dado blade on the table saw for the tenon. 

How should they fit? The first M&T is snug, and wont come apart under gravity. I'm worried that it might be too tight for the glue. Should there be any play in the joint before gluing? 

Thanks


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## rrich (Jun 24, 2009)

Your first joint?

Doesn't come apart with gravity?

It took me years to get to that point.

Congratulations!


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## Crusader (Jan 14, 2013)

Snug is good, tight is not right. If you have to use a mallet to join the pieces then it's too tight, at least that was how my father taught me.
I should clarify a bit here, when I say using a mallet I mean having to hit more than a gentle tap. I sometimes use a leather mallet, but it's a very slight tap at the end.
If you make them too tight you run the risk of creating an air pocket inside the mortise, not to mention expansion issues.

Sounds like you are on the right path. Good luck!


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## nbo10 (Jan 26, 2011)

I should say that I am using poplar. So, it's not the heaviest wood. Plus it took about an hour setting up the saw and working with test pieces.





rrich said:


> Your first joint?
> 
> Doesn't come apart with gravity?
> 
> ...


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## 4DThinker (Mar 13, 2013)

nbo10 said:


> I should say that I am using poplar. So, it's not the heaviest wood. Plus it took about an hour setting up the saw and working with test pieces.


That's about right, although that time will come down with experience. One thing the woodworking shows never show is the setup and fit testing they do before making it look easy for the show. As with most machine-aided woodworking the setup will take longer than the actual final cuts, and clean up will take even longer.


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## Oakwerks (Mar 24, 2013)

I always make the mortise about 1/16 inch longer than the tenon.... This aids in alignment, as well as providing a glue "channel"....

Sent to y'all offen' a iPad thing......


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## Oakwerks (Mar 24, 2013)

4DThinker said:


> That's about right, although that time will come down with experience. One thing the woodworking shows never show is the setup and fit testing they do before making it look easy for the show. As with most machine-aided woodworking the setup will take longer than the actual final cuts, and clean up will take even longer.


Very true.... A good setup takes time, but running the material is over in minutes....
Kind of like cooking a big meal that takes minutes consume.....

Sent to y'all offen' a iPad thing......


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## bladeburner (Jun 8, 2013)

A rule I use is; "Press On-Tap Off". 
Reason being is the first time you press the joint together, whether it's a M&T, dovetail or box joint, is that tiny wood fibers are pressed in the same direction resisting backward force. You can see the result of these fibers wearing and breaking after opening and closing the joint a few times. IOW, it gets looser, but it's still tight enough for glue. 
Congratulations on a perfect fit...first time.


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