will it stay up?

[dadiOH]

I'm going to start working on a makup table for my wife. It will be rather like a return for a desk...sticks out at a right angle from her vanity.

It will have a poplar frame covered by 3/4" ply on top of which there will be a couple of 3/4" soapstone tiles, each 1.5 ft. sq. It will have a 3" mahogany rail around it to hide the poplar, ply and tile edges. Basically, it is a torsion box without a bottom.

It is about 37" long, 18" wide and will weigh around 50-60 pounds (soapstone is heavy).

One long side abuts a wall and will be screwed to studs. One short side will be supported by the vanity. To support the other short side, I'm planning on a 1 1/2" thick mahogany knee, 12+" horizontally and about 10" vertically.

The knee will be firmly screwed to the structure of the table; I'm planning to attach it to the wall via a sliding dovetail the 3/4" oak pin of which will be screwed to a stud.

I'm thinking it will be fine attached as I have outlined; not sittable but satisfactory for its purpose. What do you think?

[woodchucker]

Then it's not a torsion box, the TB gains its strength by the top and bottom along with the webbing in between.

I think the 3/4 ply will take the weight, but I think it will sag over time, even with the mahoganny edging. Are you planning on putting any thing under the 3/4 ply, a longeron, to help support the 37 Inches. basically from end to end, not across. I think that would help the mahogany take the load. Think 2x4 on edge under the ply going the length.

[woodchucker]

Scrap what I just said, I had the orientation wrong.

[John McCoy]

"Mike Marlow" wrote in news:n4v3m1$ikf$1 @dont-email.me:

I'd think so too. The 3" rail should be ample to stop the ply from sagging, and the knee sounds more than stout enough to hold up the end (you'd use a much smaller knee in a sailing dinghy to support the mast, and that's dynamic load with a lot of leverage).

I'm not sure you need to attach the knee to the wall - just bearing against it might suffice since the top of the knee is effectively connected thru the table. But the sliding dovetail will be a technically elegant piece of work :-)

John