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Forum topic by Chelios posted 12-05-2010 06:09 PM 991 views 0 times favorited 8 replies Add to Favorites Watch
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568 posts in 3241 days

12-05-2010 06:09 PM

Topic tags/keywords: question

I don’t want to float a panel but rather just use M&T. My concern is that the width of the board is 12 in and I don’t know if making 1 big M&T or 2 or 3 smaller ones be better to allow the wood to move. It is 8/4 for the legs and 4/4 for the head board. Your input is always appreciated.


8 replies so far

View Chelios's profile


568 posts in 3241 days

#1 posted 12-05-2010 06:35 PM

It would be interesting if you shared your experiences with trying m&t joints on long sections.

thanks again

View Chelios's profile


568 posts in 3241 days

#2 posted 12-05-2010 08:35 PM

try again

View reggiek's profile


2240 posts in 3445 days

#3 posted 12-05-2010 08:49 PM

Wood type would be good to know…some moves more than others….and each are a different strength. Would also be good to know if there are any stresses on this….holding anything heavy? If not holding any heavy weight you might want to go with dominos or bisquits.

Now without knowing the wood type for sure….if it is a fairly dense hardwood…like hard maple…you can get away with a long tenon….Softer woods or open grain woods like oak, mahogany…etc…you would want to keep the tenons smaller…..To be honest…it is harder to make a big tenon that is centered and fits perfect….smaller are easier to cut and to fit. I like making the smaller tenons as they are easier to setup, cut and fit. Longer ones require more attention to detail as there is alot more area to get wrong.

-- Woodworking.....My small slice of heaven!

View sawblade1's profile


754 posts in 3201 days

#4 posted 12-05-2010 08:53 PM

Go for the double mortise and tenon One large tenon has the capabilities of splitting and working loose, as a double mortise and tenon usually has less splitting tendencies and go’s for a stronger joint also :)
keep us posted, take care :)

-- Proverbs Ch:3 vs 5,6,7 Trust in the lord with all thine heart and lean not unto your own understanding but in all your ways aknowledge him and he shall direct your path

View BarbS's profile


2434 posts in 4260 days

#5 posted 12-05-2010 09:01 PM

In my opinion, two 4” wide tenons are better than one long one in a 12” width that way. You could also leave 1/16” or 1/8” gap at the top of each mortise to allow for seasonal wood movement in that wide panel. Another suggestion: besides the tenons, you could, if you wanted, rout a long shallow channel for the raw edges of the headboard to fit into, again with a small top gap for wood movement. It will help stabilize and square up the assembly, if you’ve prepped your stock correctly. Pictures when you’re done!


View Chelios's profile


568 posts in 3241 days

#6 posted 12-05-2010 09:03 PM

Thank you both!!

Reggie- the wood is purpleheart. It is a bed for my daughter.

View Mark Shymanski's profile

Mark Shymanski

5623 posts in 3887 days

#7 posted 12-05-2010 09:08 PM

I have read about M&T joins for wide boards (so I am speaking theoretically and not from direct experience!); my understanding is that you only glue down one (usually the more constrained tenon) and let the other tenon add strength but not contribute to the tension build up when the wood moves. I believe it is a good idea to slot the unglued mortise a bit along the direction of wood movement so there is room for the tenon to move.

I hope I’ve understood this correctly, perhaps someone who actually knows what they are talking about will chime in as well :-)

-- "Checking for square? What madness is this! The cabinet is square because I will it to be so!" Jeremy Greiner LJ Topic#20953 2011 Feb 2

View a1Jim's profile


117276 posts in 3752 days

#8 posted 12-05-2010 09:51 PM

I would suggest three M&T, glue the center one and make the top and bottom tenon smaller than the mortise to allow for wood movement and peg the top bottom tenons but elongate the holes in the tenon to allow for wood movement. Like I did in my low boy.

-- wood crafting & woodworking classes

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