Table Border and Wood Movement

Here's an idea (untested perhaps) for constructing a wood tabletop border that allows for movement of the various parts without self-destruction. November 16, 2011

Question
I am building a table top from 8/4 walnut with a 8/4 Wenge boarder. The walnut top is 52"w x 79". It has seven 7 1/2" boards, and there is a 4" Wenge boarder around that. I was wondering about some ideas how to attach the Wenge to the ends of the top. Also, I hear Wenge has a pretty open grain - any suggestions how to finish them together?

Forum Responses
(Furniture Making Forum)
From contributor P:
Bread board ends make sure you allow for movement.

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From contributor Y:
You do know to allow for hygroscopic movement of the solid wood parts? If you do not do this, the top will self destruct. If I read your description correctly, you need veneer.

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From the original questioner:
I was hoping for something non-traditional. I know of all the basics out there. Just was wondering if anyone did something different.

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From contributor O:
Traditional breadboard or go to veneer!

Non-Traditional:

1. Make wenge border a loose frame around the walnut field. Basically same as solid panel doors except that the frame and the field are at the same height. Use a plywood spline set in a groove around the perimeter of walnut and interior of wenge frame. No glue on splines! The field must float. Leave a 1/4 inch space (or more) between the walnut and wenge. Go buy a couple of tubes of teak deck boat seam caulking. Caulk the space between the wenge and the walnut. The material is designed to expand and contract to take up seasonal/moisture wood movement. It may extrude and contract as the field changes size, but it is formulated to do so in as minimal way as possible and to be waterproof and have a good grip. It is also reputed to be vile stuff to deal with. You may wish to assemble while the wood is in damp phase so that caulking goes concave when the wood shrinks in dry phase rather than extrude above the surface when moving from dry to damp phase.

The caulking is designed to work with multiple strips of decking and may not have the stretch to handle the movement of your field width. It depends on some of the control of the humidity where the table lives. You may well be advised to subdivide the walnut field and assemble with floating splines and introduce the same longitudinal grooves in the field design to provide more caulking space to take up the wood movement.

2. Do not unite the mitered 45 degree corner joint of the wenge frame and fasten (ala breadboard) end caps only at one point in center and spline. Keep the corner miter a quarter or three eights open. Then create a design element that can cover the gap without filling it. Perhaps a cast ormolu bit of gilt or a slip-over raised box cap. Good luck - as you know unless you can control the humidity that field is going to move plenty,