Best way to attach shelf to table legs?

[graffis]

I'm building an end table out of solid cherry and want to attach a shelf about 6" from the floor (see attached diagram).  The legs are tapered on the inside surfaces and over an 18 inch span taper from 1.5 " square at the level of the apron to 1" square at the floor (approx. 2 degree taper).  The shelf is 3/4" thick and I would like to have the outside leg surfaces be about 1/8" proud of the shelf edges when mounted.  What is the best way to join the shelf to the legs, allowing for seasonal expansion and showing no gaps where the shelf meets the legs.  I know I will have to notch the corners of the shelf but do I need to dado the table legs to accomodate the notched shelf edges?  My concern is that by doing so, the dados will weaken the structural integrety of the the legs. Any help will be appreciated.

Table with shelf.pdf

[Chris H]

There are many options, but here are a couple that I would probably go to first.

 

The first is to notch into the leg.  Technically you do weaken the leg slightly, but with a tight fitting joint and a solid wood shelf filling the gap you have cut out, the weakening is negligible.  Also, by connecting the legs together at a lower point like that, you are allowing the table to distribute weight across the legs better.  So you have weakened the leg, but strengthened the table as a whole.

 

Another option that is popular is a loose tenon.  A cheap and durable loose tennon is a dowel.  It's a little easier imo to get a tight fit with dowels, but you will get slightly more strength with a notched approach. Again, I don't know that the strength differential is terribly important.    

 

Another option would be to essentially build supports (aprons) for the shelf that could be joined any number of ways, but the most durable being a M/T joint.  

[rodger.]

Chris had a great response. Dowels are quite popular in the situation you describe

[G S Haydon]

+1, Great advice Chris.

[dwacker]

The way you have it set up with a solid wood shelf its going to expand and contract pushing the legs in and out if you use any sort of solid joinery. This is going to make the table wobble and may even break the upper leg joints. I would think about making the shelf a breadboard or veneered.

[Egraff]

+1 on what Chris said. Personally, I'd just go with the dowel approach and call it good. Best, EG

[Pwalter5110]

I have also wondered the best way to do this with a solid wood shelf. I always thought that the expansion of the shelf would break the legs if its not built right.  So far, the only thing I can think of that I can guarantee, is attaching breadboard ends to the table legs. The expansion of the breadboard ends will go the same direction of the table aprons. Then have the shelf "float" in the breadboard ends.

 

The only other approach I can think of is glueing a dowel into the leg, and notching the underside of the shelf so that the shelf sits on top of the dowel, instead of glueing the shelf into the legs. That way you could just lift the shelf right off the dowels if need be, but some seasons you might have a gap, and other times you may not.

[wdwerker]

It is so close to the floor you could glue a small bracket to each leg and put an oval hole for a screw to hold the shelf down. A 1" triangle with a "vee" groove would never be seen.

[Grain Guy]

I built a coffee table three or so years ago and notched the inside corner to except the shelf. It worked great and is still in good shape. I used quarter sawn walnut for the 1/2" thick shelf so expansion would be in it thickness not its width. I like that it is inserted and not a butt joint with dowels. That way when expansion and contraction occurs on any of the parts there is no seam to open up.

There are pros and cons for all joinery. You just need to examine your materials, design, skill set, and tooling and pick the best one possible. Follow your best judgment and you can't go wrong.

[Llama]

I use dowels for this type of shelf. Always looks good.

[Grain Guy]

New idea. Turn your legs up on a 45* and cross cut a dado for your shelf. Then clip the corner of your shelf at a 45*. Then put a dowel in it. Pow!

[graffis]

Thanks everyone!  I went with the dowel approach.  Let you know how things work out after the rainy season.