Making a Large Conference Table in Pieces
Ideas and discussion for making a large White Oak table in pieces for disassembly and moving. July 11, 2009
Question
I am building a conference table for the local Boys and Girls Club from a white oak tree that was cut down on the property. The material has been milled and kiln dried. The table design is a boat shape top 4' at each end and 5' in the middle and 20' long. I was planning to use an apron set up with eight legs so the table can be separated in the middle creating two 10' tables. I also plan to have a joint in the middle of each end connected with tite joint hardware. My concerns of course are wood movement of the 1 3/4" thick top. What is the best way to allow for the 1 1/2" of movement I can expect? Is this project feasible?
Forum Responses
(Furniture Making Forum)
From contributor O:
I made a tavern table out of white oak about three feet wide by about six feet long a few years ago. It was about one inch thick after planing flatish. The breadboard ends indicated to me it moved about a quarter of an inch over its width and then it stayed there. My guess would be the core dried out a bit more after it was planed. Other people may disagree but there is no way it will move close to that much from KD to aired out/seasoned. If anything, use those little clips to attach the base to the top. Unless you do something to trap the oak on its width like a mitered trim or something I think it's a non-issue.
From contributor J:
It would help to know the grain direction you plan on, and I find "a joint in the middle of each end connected with tite joint hardware" a little confusing. Can you clarify?
From contributor B:
I built a 3' x 8' table out of quartersawn white oak. I used shop made slotted fasteners to hold the top in place and still allow for movement. It is still in great shape nearly a decade later, including three years that it sat outside under cover.
From contributor J:
Something to consider: each half of that table will weigh over 300 pounds. Not fun to move around.
From the original questioner:
I was planning to make the table in four pieces where there is a joint in the middle and one running lengthwise along each end. The grain will go the long way so most of the shrinkage will be along the width.
From contributor J:
With the grain running lengthwise, you're looking at perhaps 1/2" change in width, seasonally, probably less. Now I understand where the joints splitting each end in two are, but I don't know why you'd want such joints.
From the original questioner:
The joints on each end of the table would be to make the moving easier. I’m not sure if it's a good idea or not, but just thought it would reduce the weight of each piece for disassembly and moving.
From contributor J:
I'm thinking that splitting the ends is a non-starter, for a variety of reasons. Tite joint hardware isn't designed for the stresses that would be involved in this application, isn't designed for repeated disassembly and reassembly, and isn't especially easy to take apart and put back together so nobody would ever actually use this "feature" of your table which is good because you've only got four legs on each end section, so splitting one of these ends leaves you with two 2-legged sections which can't stand on their own and are heavy enough to seriously hurt someone if they topple. So no, that part of the idea isn't feasible.
I would radically simplify this whole idea before getting too far into it. Maybe chop the length into four roughly square tables, maybe with pedestal or trestle bases. Let them be on the rustic side, because you're not going to get the sections to mate perfectly when they're brought up against each other on an uneven floor. And make sure that the club will have a few strong people around at any time they want to rearrange, because there's no way to make an 8/4 oak top light.
From contributor W:
Why not make four tables and use other hardware to put the tables together. Then the user could have four small work session tables for classes. The four legs on each would make it safer and easier to move at some later date.
From Gene Wengert, forum technical advisor:
If kiln dried to around 7% MC, at the extreme you might reach 12% MC if stored outside for a long time and 6% MC if used inside in the wintertime. Appalachian or northern oak shrinks and swells about 1/3% in width for each 1% MC change (probably less due to the thickness of your table), so you might see 2% size change, but probably closer to 1-1/2%. So, for 5', that is under 1" total width change. I do think that making two or four tables is a great idea, especially due to the weight.
From contributor W:
First off, your table will be really impressive. Sounds like a beauty. Making a 20' table in two (or more) pieces is a really good idea, especially if you are the one who has to deliver it. I would not worry about locking those pieces together, their weight will keep them where they are placed. Check with how they will use the space. A conference table like that is not often moved, so sizes of individual pieces may not be an issue.
The grain will not move between the two tops if they are placed end grain to end grain. However, the grain will shift between the rail and the top. I would allow for an inch of movement to be safe. If you make buttons (a block with a rebate) set into a deep plow, the amount of movement is not an issue. Pin the top in the center, so the movement happens more or less equally at each side.
