Greg Guarino <
gdgu...@gmail.com> wrote in
news:mehli2$osm$
1...@dont-email.me:
>
https://lh3.googleusercontent.com/-
WPUu7fFmjLo/VQxWVF1CfcI/AAAAAAAAAHI/
> rR4bsE5jcUU/w1118-h534-no/tenons.jpg
>
> The drawing shows a through tenon and a blind tenon that meet (or
> nearly so) inside a leg.
>
> Questions:
>
> How deep is deep enough to make a mortise and tenon joint useful?
Generally you want a longer tenon in preference to a shorter
one, but it's usually determined by whatever you're putting
the mortise into.
For a smallish piece like your's, I'd think a 1/2 inch
tenon would be fine.
> Are there other strategies to deal with this situation?
Well, normally both tenons are blind and meet inside the
leg - both being cut @ 45 degrees on the end like a miter.
> Would you make a blind tenon that was smaller in the vertical
> dimension, allowing it to go deeper, through the other tenon?
No - if I was doing a thru tenon for aesthetic reasons,
I'd just butt the blind tenon to it, as you show.
> Would you bother making the blind mortise and tenon joint at all, or
> might you choose some other kind of joint, since it won't show?
Yes. Mortise and tenon is easy and strong, it's the best
way to attach the rail to the leg. If I was worried about
the strength of the short tenon, I might add a triangular
brace/glue block on the inside (joining the two rails -
it'd have to be notched to clear the corner of the leg).
John