Is a 3cm Tenon Long Enough in This Case?

[jasonwood]

Hi all,

I've just routed the mortises for the cross members of the headboard and footboard of a bed I'm making.

The mortises are just over 3cm deep. Can't really get them any deeper with the router bits I have.

This image below shows the size of the mortise and the cross member that will eventually have a tenon cut and fitted into the mortise.

Based on these sizes and the application as part of a headboard, do you think 3cm is deep enough for the mortises or would I be better off chiseling the mortises a little deeper?

I thought about perhaps using a dowel to reinforce the joint, where you offset the hole in the tenon slightly so when the dowel is driven into place, it pulls the tenon tightly into the mortise, but this is softwood so I'm not sure if that would be a good idea?

Thanks for any advice
Jason

 

[Hudson Carpentry]

I don't think you'll have a problem. Instead of dowel in the hole why not do a pegged M&T?

 

[jasonwood]

Thanks for the reply.

I'm not sure what exactly a pegged mortise and tenon is... I'll do a google search.

 

[Hudson Carpentry]

I read your post wrong sorry, what you was talking about doing with the dowel is a pegged M&T, for some bizarre reason I thought you meant drill a hole down into the mortise to put a dowel in (kind of extending the M&T) (hammer) (hammer)

 

[joiner_sim]

When I made a headboard before, I morticed all the way thru the uprights (70mm I think) and wedged them. See http://www.freewebs.com/simonswoodwork/bedheadboardproject.htm for info on that. However, the thru-mortices were probably not required and I probably only did them to test large mortices like that by hand.

A bed headboard doesn't really get any pressure put on it. Unless it's actually part of the bed! So I'd say that you're 30mm tennon dowelled would be perfectly fine. Unfortunatley though, I read it as you're actually making the whole bed. So you would have to decide yourself wether or not the joint will be under alot of pressure in your design. Depending on the design thats how I'd decide wether it was a strong enough joint (e.g. if you're using metal brackets to reinforce the bed the joint shouldn't be under much stress)

Hope that helps....

JS

 

[kirkpoore1]

Jason:

I think your depth is OK. Your tenon may be a little narrow--I'd take it up to 20mm or so, since you've got plenty of meat in that post.

As for drawboring (the offset peg stuff), I would peg the tenon but not drawbore. Drawboring can help pull a joint tight, but if you clamp it good before you drill the hole it will already be tight when you drive the peg into place.

Kirk