I am cutting haunched tenons on some table aprons. The aprons are about 5 1/4″ long, the center section of the tenon will be through (about 2.5″ wide), the haunched areas will be 1/4-3/8″ long. Since the hauched area will be about 4 3/4″ wide overall, should I leave some space for movement between the mortise for the haunched tenon? (the through tenon portion would remain a tight fit) I believe I do, but just wanted another opinion.
Thanks,
Steve
Replies
Ok...I made a quick sketch to clarify my question, hopefully this will prompt a reply or two
thanks again,
Steve
On my fitting.. here is the rule I go by.. If it can be fitted by hand and a gentle mallet tap.. it is snug, but gives a peach for expansion (remember wood will only expand cross grain).. The only thing to worry about is if the wood expands too much, it might split the leg, but I can;t see the expansion ever being enough to do this.. If the leg splitting worries you that much, set an oak peg cross grain above and below the tenon..
I will do this on my rails when I key a joint, set an oak peg on the outer end to give it cross grain strength..
Steve,You can solve the top problem by letting the haunch go all the way to the top of the leg. The small piece of wood boxing in the haunch at the top will probably break off during assembly anyway.On the bottom you only have to worry about the distance from the main tenon to end of the haunch (I am guessing about 1 in?) I don't think you would need much of a gap to deal with movement across 1in.Good luck,Dean
Steve, if your wood is kd you probably will not see much expansion in 4 3/4 inches of width. Doubled tenons over a wider piece (like a door kick rail) might like it though. aloha, mike
Steve,
If your apron is quarter-sawn it will expand and contract (across its width) only half as much as it would if plainsawn; rift sawn is approximately miday between QS & plain.
Good luck,-Jazzdogg-
"Don't ask yourself what the world needs. Ask yourself what makes you come alive, and go do that, because what the world needs is people who have come alive." Gil Bailie
Thanks for all the tips guys! I may as well play it safe and leave some extra space in the joint, guess it won't hurt anything.
Steve
This forum post is now archived. Commenting has been disabled