# Wood movement



## mbalboa (Jul 24, 2008)

I want to make a tabletop with four red oak sections separated by a "plus sign" made of two pieces of maple. I am worried about how to join them for problems caused by expansion and contraction. The oak will have all its gran running horizontally, and one of the maple sections as well, but the other section will have it's grain running vertically rather than horizontally. Any thoughts on the best way to join these boards?


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## cabinetman (Jul 5, 2007)

*WELCOME TO THE FORUM*

If you are using glued up solid lumber for the Red Oak fields, cut a substrate the size of the top out of 3/4" substrate. Attach each of the four sections with screws from the underside along the centerline of each glued up section. What could happen is that since solid wood may expand across the grain, it will move against the horizontal Maple part of the "+". 

Or, you could use 3/4" Red Oak plywood for the fields, and Maple plywood for the "+", and never have any movement issues. The pieces can be glued right to a 3/4" substrate.

In either procedure you will probably add a wood edging to trim off the edge. The picture below is of a sample table I made entirely of 3/4" Maple plywood scraps. There is a total of 61 pieces of plywood fitted for the top.
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## clampman (Oct 20, 2006)

I would glue up the table out of oak, then inlay the maple plus sign with maple veneer, with a generous border of oak around the maple plus sign. I would either miter the centers of the maple + or make the counter-grain sections of + out of two pieces of maple veneer with the longer + leg going with the oak grain.


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## mbalboa (Jul 24, 2008)

Thanks for the responses! I think that using plywood here will probably be my best bet. I don't think i'm at the point where i can comfortably do inlays. I do have another question though. Wouldn't inlays move as well? I can't imagine that they don't experience a lot of the same problems that normal wood does, but I could be wrong. Thoughts?


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## clampman (Oct 20, 2006)

If you made the plus sign as described, with a generous border around it, say 4 " and your table width were 32" that would leave 24" of cross grain inlay. But with the cross grain inlay mitered at the center, you would have a total of only 12" of cross grain movement to deal with, which a veneer, could most likely handle (especially if you were to use a nice burl as opposed to plain maple), assuming you are using well dried stock for the top. But if it didn't, whatever movement occurred would be purely cosmetic. 

If it looked too horrible, you could always take off the table top, run it through a wide belt sander, and still have a nice table top.

That would not be an option if you were using solid material unless you made each edge of the cross grained section of maple like the bread board ends of country furniture.

Plywood would be the best option for stability, if you think the top will hold up long enough and look the way you want it too.


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## andy builds (Aug 1, 2008)

It's just a top, have you thought about something as simple as double slot biscuit joinery and clamping?? normally works out quite well for something as simple as that....


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## GeorgeC (Jul 30, 2008)

*Oak Problems*

I have had considerable problems with using large pieces of oak as you are describing. I have had problems both with splitting and with shrinking. The shrinking problems have even occured with 4" wide by 36" long pieces. All of this was with wood that had been stored in my garage and was supposedly cured.

The problem is that when the wood that has been stored in the humidity of the outside comes into the air conditioned house it dries further. I live in the panhandle of Florida so my outside humidity may be higher than yours.

If you have much humidity where you live I would recommend that you let the wood cure for a couple of months in the interior environment before building. If after that you can air condition your shop all the better.

G


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