Moulding on Tabletop Question

[Mike Corwin]

Hi Everyone - I'm making a Federal style tea table for a client out of solid walnut.  The top will be around 30" wide, and the client has requested that there be a raised-lip moulding so that nothing can roll off.  I was thinking of cutting a tongue on the tabletop and making some moulding with a groove in it and attaching it to the top with mitered corners like a picture frame, however I'm sure that the wood movement across the width of the top would blow the miters open in time.  What is the best way of attaching this raised moulding to the top with consideration to wood movement?  Attached is a photo of the basic concept, any info would be most helpful!

[wdwerker]

The top gets treated like a frame and panel door. The grooves on the cross grain sides of the top need to be deep enough to allow for the movement. You won't need any extra depth on the end grain sides, the top won't change length . I would provide some sort of extra support for the mitered corners, A kerf and a spline is the first thing that comes to mind.

Or you use a veneered top and all those problems go away. You could bandsaw and drum sand some thick veneers (1/8 ) and glue them to both sides of a piece of Baltic birch. They would go 90 degrees to the face grain of the ply. Even the underside should be about the same thickness veneer but not nessasarily the pretty walnut, sap streaked walnut or poplar would do. Just needs to be balanced construction. I would still spline the miters.

[..Kev]

Last time I built a table along those lines, I used ply for the top for that exact same reason.

[Mike Corwin]

Thanks for the advice, I completely overlooked making the groove deeper in the long grain sides to accommodate movement.  Cheers!