Help! - Wood Movement Question

[Jon Farley]

I recently volunteered to make a new free-standing altar (really just a fancy table) for our church sanctuary. I have designed it to match the wall-affixed altar that is already there and will remain. Now that I have the design ready to go I have begun thinking about the actual construction and I'm wondering what to do about a potential wood movement-related problem. The new altar will have a top made from 3 pieces of edge-glued red oak, each about 7.5" wide and 3/4" thick.

Now here's what I'm worried about: The the table top is to have a separate thumbnail-type molding around all the edges. The sides are not a problem, but attaching this molding to the end grain of the table top is. Any contraction/expansion with the table top could cause problems, not the least of which would be pushing apart the mitered corners. Anyone have any suggestions? Thanks...Jon

[tod evans]

jon, simply rout the profile into the top itself, don`t try to apply it...02 tod

[Dave Fifield]

Or, you could route a sliding dovetail into the rear of the moulding and float it on the ends of the alter top. You'll probably want to forget about mitering the corners though....

[Jon Farley]

jon, simply rout the profile into the top itself, don`t try to apply it...02 tod

Yes, that is a simple fix and I thought of it, but I want it to be consistent with the present alter, which does have a separate molding, and which does, in a way, look nicer as it covers up the end grain of the table top with the long grain of the molding.

[Jon Farley]

Or, you could route a sliding dovetail into the rear of the moulding and float it on the ends of the alter top.

This is something I have considered. Would a simple tongue and groove work, too?

I am still concerned about the miters being pushed apart. It seems as though this would happen regardless of a sliding dovetail.

And, if I did someting like this would I have to let some sort of a small gap in beween the perimeter of the table top and molding to allow for expansion without breaking apart the miters? Just thinking out loud. Thanks...Jon

[Jon Farley]

Here is a picture of the corner of the present altar to illustrate what I am trying to duplicate. Though it really doesn't change anything about the nature of my question, I'll just note that the one I'm building is an eight-sided table, so I won't be working with 90 degree corners.

[tod evans]

jon, if you`re doing an octagon you really should consider using a veneered panel for the field.....02 tod

[Steve Clardy]

Is the present one really a solid wood top? Or a veener top?
Might pay to look underneath.
I wouldn't apply trim to end grain. It's going to move, breaking the joints more than likely.