Round top dining table

[John Raeder]

I am building a round top dining table all out or cherry wood. The final diameter will be 5 ft, but I want to join several boards 3/4" together (using biscuits) and then cut them to a circle of 4' 6" diameter using a circle cutting jig with a plunge router. I then want to add eight 3" wide curved cherry border pieces out of 6/4 or 8/4 cherry to give the illusion of the top being thicker and as a design feature. I live in Reno, Nevada which has a very dry climate throughout the year, but I'm still worried about differential expansion and contraction of the central boards and the border pieces which will have different grain orientation. I'm considering making the central 4' 6" diameter portion out of 3/4" thick plywood and veneering that with 1/8" thick cherry veneer which I'm thinking would not expand or shrink much. obviating the problem with the different grain direction of the border pieces, but that would require a lot more work. I'm hoping that with the dry climate here I could get away with the first option, but would like any opinions from more experienced woodworkers. This is an example of what I'm trying to create, although hopefully less rustic and more elegant. https://www.homedepot.com/p/Home-Decorators-Collection-Cane-Bark-Round-Dining-Table-9415600860/303578635

[wtnhighlander]

Even in dry climates, its a gamble to break the rules of wood movement. The way I've seen similar tables made is to not glue the main part together, but to leave the boards as loose slats, perhaps with ship-lap or tongue & groove edges. Wrap them in a solid frame, held in a groove like a frame & panel door. That allows a bit of expansion, but the table top will have grooves / gaps at the joints. Battens and screws into the underside can help keep it flat and strong.

For a smooth top, veneered ply is your safest bet. If you build the plywood slab and wrap it with the solid wood rim first, then veneer the entire top, you can get the illusion of a solid glue-up. Or veneer the ply separately, which allows for decorative patterns or marquetry. In either case, be sure to apply veneer to both sides of the ply, as doing one will "unbalance" the layers, and is garanteed to make to warp.

Don't ask me how I know...

[drzaius]

If you go solid wood top, then make the curved build up pieces so that the grain runs in the same direction as the part of the top they are glued to. Then there will be no issue with wood movement and the edge will look better too.

[Martin-IT]

It looks to me, like the outer circle is 'fixed', with the inner blank floating with a miter into the outer edge. The gap will shrink and expand with the seasonal change (humid summer vs dry heater winter) between the outer rink and the inner blank. If you do attempt it, finish all the pieces before assembly. I made raised panel doors that I finish after assembly, in the winter I see a streak of unfinished wood with an ridge of finish, that disappear in the summer. 

Using plywood & veneer with the inner part will help stabilize it. Good luck and post pictures of the projects.

[Ronn W]

When I make a table top with a solid wood border, I prefer veneered plywood or MDF. High density particle board is another option. Since yours is a large table -  I would not use MDF.  Sourcing plywood over 48"wide could be a challenge.   You may want to rethink the table top thickness.  For a table of that size, 3/4" seems too thin.

Another approach, assuming that you have the equipment/tools to veneer a 60" table top.  Is to veneer the entire top making it look like a border also veneer the edges.  If I were doing that I would make the top 1/1 2" thick.  This opens up some interesting possibilites with grain direct, patterns, etc. Can very elegant if you want.

If you veneer the edges - use double thickness veneer on the edge to allow very light easing of the edge without sanding through the veneer.

Good luck.  Should be a great project.

[riqmar]

Rather than buy your material already surfaced  [to 3/4 or 1 or 1 1/4 etc.] you might consider buying it "blanked" or "hit-or-miss".  The extra 3/16" can make a big diff  [4/4 material is 15/16" etc....]

Regarding your actual table top: there is another way to achieve a thick edge, but it works only if you do not care about seeing a frame around the perimeter.  For example, when you are roughing out the boards, each one in the central area of the top is cut a bit long, say 3 inches or so at each end.  These offcuts [which you would do well to mark for later reference] will then get glued to what is to be the underside of the top before the individual boards are ripped to finished width and glu-able edges.  If this makes sense to you then you will see that the problems of wood shrinkage are eliminated--in fact, gluing the table boards together is about as easy as standard, but with a thicker edge included.

Since you are making a round top, you can do a pretty good job of slip matching the grain as you work your way around the top.............which is to say that the thickened edge will either not be noticed or, if it is, it will look purposeful.