Tricky Conference Table Tips
Another extended discussion of how to make a complicated conference table — and whether a beginner should even attempt it. March 14, 2006
Question
I will be building a conference table for a client soon. I have been a woodworker for many years, mainly cabinets, mantles, entertainment centers and smaller pieces of furniture, so I am not green to woodworking, but I have never built a table of this size before.
Here is the situation. Table size 5' x 10' oval. Will have a lift-up center section approximately 20" x 80" oval. The customer wants the top out of walnut veneer with maple inlays for accents. The walnut veneers will all be of smaller pieces to accommodate the layout of the grain that they want. The outer rim of the table will be solid walnut 1 1/4 - 1 1/2" high and only about 1/2" thick. The inner rims of the table where the two pieces meet will be solid walnut, also of the same size. No problems so far.
As you can see from their requirements, I must be able to achieve minimal movement of the table top so the two pieces will move freely in and out of one another. I can't have a large gap, maybe 1/16". It has to be as close a fit as possible. If I glue all of this up to an MDF core using veneers of only .060 or less, will I be okay or will there still be a chance for table top movement that would cause a bind or the veneer to separate or buckle? What about the solid wood edging on my top?
Forum Responses
(Furniture Making Forum)
From contributor P:
The veneered portions won't move much, but it's not clear to me how you will fabricate the solid walnut edge bands. Also, how do you intend to finish and move this thing? A good even finish is critical to make a C T look great. And a 5 x 10 oval is a beast to move around.
From the original questioner:
First, the table complete will be assembled in the shop and the mechanical lift for the center section will be tested, then disassembled and reassembled in the conference room. So when moving the top itself, it will have this big hole in the center where the other section will go, and that will lighten the load. Three people and good furniture dollies and it will move okay. As far as the walnut edging, I was figuring biscuit and glue, and maybe even a wider band of walnut, as I would like to put a nice big radius on the edges of the table. The table top would not be a true oval - it would be straight on both sides and the ends would have a 30" radius. I am not sure yet exactly how to achieve a nice consistent band around the table, because there would have to be seams and I want this to look as nice as possible. I was thinking of sawing the pieces out of solid to conform to the radius on the table edge so I don't have to worry about trying to bend any wood. Any input on this would also be welcome.
From contributor D:
Honeycomb or torsion box construction is useful, as well as a solid plan for sizing and joining multiple vacuum bagged panels in the shop. Swinging arcs to size panels and edgings is basic to large scale curve work.
From contributor P:
I've got experience in large tables and I'll give you one hint: a wider edge band, cut out of solid and biscuited to the panel, will be easier to build. However, in the interior where the lift meets the table edge, wood movement may be a problem, and the walnut width should be minimized. So biscuiting it will be difficult.
The sanding is critical to the finishing, and the finishing is very tricky. I hope that you got a pretty penny for this thing - I wouldn't touch it for less than 15k (not including the lift) myself. And if you haven't done one before, I also hope that your client doesn't know the difference between good work and bad, as it will be difficult to pull the whole thing together without a lot of experience with tables in general.
From the original questioner:
Thanks for the advice. 15K is exactly what I got for it.
From contributor M:
I would use a thicker core for the top. At minimum of 1", where the two top come together, drop down 1/8", then into a bevel. Do not use hardwood on these edges - just veneer the core of the top - less movement!
From contributor F:
If you think the tolerances are too tight, talk to your client and see if they can be stretched. You will of course have a better idea after it is done and has lived for a while. That will guide you on the next one.
From contributor V:
Build a long and very stiff trammel for a router. If you don't have a CNC router, a trammeled router is a great tool to radius the table ends and the wood edging. I have a large work space and one of my trammels is 21 feet long. An interesting thing I discovered is that when you are routing curves whose radii are over 100", an error in radius of an eighth of an inch between the convex and concave sides of the joint makes little difference.
I too think that the tolerances in the gap for the lift section should be the furniture maker's decision within reason.
From contributor E:
Make sure your finish is top notch. This is the connector with the client. This is what they see, touch and feel. You can have the best designed and constructed table, but if the finish is not up to par, it will mar the perception of the work. Most conference tables use a conversion varnish or 2PK urethane finish for durability.
From contributor N:
I share the above opinion about the finish. One important consideration is the difference in the rate of movement between the hardwood and the sheet stock. This is the source of many cracks in otherwise great looking finishes. With a table this big, I would opt for the poly finish. More difficult to apply, but not near as likely to crack at the joints as many conversion varnishes.
