Need advice, will wood movement allow this?

[Voytek Jarnot]

Attached is a rough first sketch of a queen size guest bed I'm designing. In the current design, the posts are about 2"x4" and the headboard is 1.75"x11"x69". The posts and rails will be maple, headboard and footboard will be walnut.

Here's my question: how would you join the headboard to the posts to survive the inevitable expansion/contraction of the headboard?

Thanks!

[Don Baer]

Here is a post by Ryan Singer, Mark Singers son on how he made his bed. He used Mortise and Tenions. Here's the thread.
http://www.sawmillcreek.org/showthread.php?t=15151

[Voytek Jarnot]

Here is a post by Ryan Singer, Mark Singers son on how he made his bed. He used Mortise and Tenions. Here's the thread.
http://www.sawmillcreek.org/showthread.php?t=15151
Thanks, I've read that; but that headboard design is completely different. I was asking specifically about the quick sketch I posted, not so much a general headboard-post joint question.

[Steve Wargo]

Cut your bridle slot in the post then attach it with two dowels from the back drilling into the front piece of the mortise, but not through it. Put the first pin about an inch up from the bottom, and the second one about 3" up from the bottom and slot the hole for the second one. I think that this would work. I would probably glue the pins in place, but certainly not cross grain. Another option is to veneer the head board using a good ply or MDF for the substrait. Then wood movement isn't an issue. Perhaps Mark Singer will chime in. He's pretty darn good at the design/construction of a piece. Hope I was some help.

[Steve Schoene]

I would glue several inches of the headboard in place in the bottom. The headboard would then have a slot wide enough to accommodate the movement placed through it an inch or so down from the top of the bed post. I would then put a dowel or loose tenon through this slot, gluing it into the front half of the post, unglued through the slot, and then glued at the back of the post. It would only be visible from the back. This would allow the wood movement in the headboard, and at the same time reinforce the post so that stress on the top to the headboard doesn't tend to split the post. I see that as the principle risk since that would be a leveraged force.

[Mike Williams]

Voytek,

There was a good article by Christian Becksvoort in FWW 165 titled "Understanding Wood Movement" that talked directly to the connection of a slab headboard mortised into the vertical bed posts. Basically it suggested a single slightly long mortise (vertically) with the tenon glued and pinned only at the middle of the joint.

Mike

[Jim W. White]

Just my opinion, but longitudinal moisture movement in most species is not nearly the problem as axial. I think your design for the head and foot boards would hold up fine.

...Jim in Idaho

Just to add some details... Longitudinal shrinkage is normally only about .1% which equates to about 1/16" of an inch from an 8ft. stick. In most species it's considered negligible with possible exception of having excessive reaction wood or juvenile wood in the stick.

[Jim Becker]

I like Mr Wargo's idea...kinda the same treatment as a breadboard end in a different application.

[Mark Singer]

What Steve suggested would work. If you use veneer ...make your own. A very simple way to do this is to not glue the bridal or slip joint ...use screws and oversize them into the verticles...screwing from the back. Drill a small pilot hole in the back and as the wood moves across the grain the screw moves....only 1/16" is all the movement you can ever get there at the most... Start with dry wood.

http://www.sawmillcreek.org/showthread.php?t=5510&highlight=peruvian

http://www.sawmillcreek.org/attachment.php?attachmentid=13918&d=1103720796

[Voytek Jarnot]

Thanks for the good advice folks, I'll update this thread with the solution I eventually use. I typically wait until I actually need to execute a solution to see which one I feel capable of accomplishing ... this'll be my third woodworking project, so I'm still doing much more learning that doing.