wood movement and design question

[Andrew DePalma]

Hey All,

Designing a new table and am wondering if I am going to have a wood movement issue here and would love some thoughts. First let me say that I feel like I know enough to be paranoid about wood movement after reading Bruce Hoadley's "understanding wood" book so thought I would get a couple other eyes on it.
My primary concern with this design is the beam running through the arches. It is going to be 4 inches and tangential expansion and contraction will be happening on the vertical/y axis. 3 questions:



Will the movement across the 4 inch beam be enough to cause warping or cracking in either the arches or the table top?
If I were going to make the beam "float" in the channel carved out of the arches (to avoid any wood movement issues on the arches) to give the beam room to expand with 4) 3/4" dowels running through the arches on each side, would that be enough support to keep the table stable or is that just a bad design idea?


If you need me to illustrate my idea in question 2 I can do that and repost. Just let me know. Thanks for the help! 337392

[Andrew Hughes]

I don't think it's going to be a problem you didn't mention what wood your using some are more stable than others.Id feel okay guleing with dowels.That spot should be a strong link for the table.
Maybe even screws covered with plugs.
Gook luck

[John TenEyck]

It doesn't look much different than a mortise and tenon joint on a large door. Some of those are larger than 4" and survive for decades, even centuries. I think it'll be fine all glued together.

John

[Wayne Lomman]

Good styling Andrew. The structure looks OK to me. As John says, it should perform like a mortise and tenon. If you are concerned about movement in the curved sections, rough cut them now, seal the end grain and give them extra seasoning time. This is what we always did with the deep curved top splats cut from 4" Brazilian Mahogany. They were band sawn the minute the timber arrived and we shared the lunch room (only warm room in the factory) with them until the were stabilised.