[mr.crumpet123]

I was recently commissioned to build an 8' by 54" conference table for a law office. I will be joining 6 or 7 cherry boards together side by side. Do you think, with proper bridge support every foot and a half or so, that 4/4 stock cherry will be strong enough for the table to last? Also, what joint should I use to join the boards together? I was thinking tongue and groove, but is there a stronger joint I should use?
Thanks,
Clark N.

 

[ryan50hrl]

Is the end grain going to be visible on each end of the table?

 

[cabinetman]

I was recently commissioned to build an 8' by 54" conference table for a law office. I will be joining 6 or 7 cherry boards together side by side. Do you think, with proper bridge support every foot and a half or so, that 4/4 stock cherry will be strong enough for the table to last? Also, what joint should I use to join the boards together? I was thinking tongue and groove, but is there a stronger joint I should use?
Thanks,
Clark N.

In using solid wood for a table top, the wider the boards are the more likely they may react to expansion and contraction. That happens across the grain, so your "bridges" should not be screwed tightly to each board. You could screw to each board if you use a slotted hole, which would allow for any movement.

If you are planning for a "breadboard" end, that should be installed the same way. You could run a blind groove at the ends, and mill a tongue on the BB end. You could just use a blind spline.

For the glue up, you could just edge glue, clamp and use cauls to keep the boards flat. I would be reluctant to use a T&G, as there's the possibility of being a little off. I would prefer to use a blind spline instead of a T&G.

Your stock should be acclimated before fabrication. I like to use KD lumber. Apply your finish to both the top and the bottom.

.

 

[mr.crumpet123]

Is the end grain going to be visible on each end of the table?

No, I will be using 2" of figured cherry around the whole edge of the table, and there will be molding starting underneath the very edge of the table.

 

[mr.crumpet123]

In using solid wood for a table top, the wider the boards are the more likely they may react to expansion and contraction. That happens across the grain, so your "bridges" should not be screwed tightly to each board. You could screw to each board if you use a slotted hole, which would allow for any movement.

If you are planning for a "breadboard" end, that should be installed the same way. You could run a blind groove at the ends, and mill a tongue on the BB end. You could just use a blind spline.

For the glue up, you could just edge glue, clamp and use cauls to keep the boards flat. I would be reluctant to use a T&G, as there's the possibility of being a little off. I would prefer to use a blind spline instead of a T&G.

Your stock should be acclimated before fabrication. I like to use KD lumber. Apply your finish to both the top and the bottom.

.

Thank you very much. I have heard that the wider the boards are the more trouble you will encounter, and I have now decided to make my boards less wide.

As for my "bridges", I did not know expansion and contraction occurred more often across the grain, and now will use slotted holes.

As for the blind spline, how wide do you suggest to make each spline?

 

[cabinetman]

As for the blind spline, how wide do you suggest to make each spline?

I use a ½" slot cutter, and it makes a ¼ wide slot in each piece. My splines are ¼" x 7/8" - 15/16". I make a very slight chamfer on the long edges.

.,

 

[rrich]

I hate to suggest a particular brand of anything but there is a cheap and simple jig to help you with your problem. It is called a dowel drilling jig from Rockler. ($20 or so)

http://www.rockler.com/product.cfm?page=18059&site=ROCKLER

Lay out the boards for the table top and clamp them into the final aesthetic arrangement. Draw a line across the joints about every 6 inches. It should be reasonably square to the edges. Use the jig to drill the holes for the dowels and aligned with your marks.

When you glue up, the dowels add that bit of extra alignment. Glue up just as though you were doing edge joining of two boards.

There is one other thing to think about. A wide belt sander larger than 54" is going to be difficult to find. You may want to make the top in two pieces and then when you assemble the table on site use table leaf hardware to connect and align.

 

[mr.crumpet123]

Well, I have my 10 boards planed and squared to each other, and am now ready to join them. I am planning on using a slot cutter that will cut slots 1/2" deep, by 1/4" tall to make the blind spline joints. As for the actual splines, should I use Baltic Birch plywood, or solid Baltic Birch? (Across the grain of course). Thanks again