Wood movement

[David Klug]

I'm building a display cabinent for our church and I'll be making it out of 1/4 sawn oak. It will be 10' long 42" high in the back with a 25 degree slope to the front. The top will be around 16" wide by 10' long with sides around 14" wide. I am planing on using plywood for the shelving. What I am wondering is how much concern I should have about wood movement, if any, and how I should handle it. I was thinking that I would glue a couple dowels in the stiles and let the strechers float on them. Would this work or is there a better way?

DK

[Steve Cox]

Let me see if I have this right. The grain will be running the long direction of the piece. The sides and top will be slab as opposed to frame and panel. There will be a face frame on the front to help support the shelving. In that case, there will be no problem with wood movement. Where you have probelms with movement is when the grain of two pieces are at right angles to each other or where the wood is prevented from expanding/contracting across its' face by something like a rame or breadboard end. If you build a case out of solid wood with the grain running the same direction all the way around, it will expand/contract at the same rate and you have no problem. If you attach the plywood shelves to the case rigidly (biscuits, glued dados, etc) you will create a problem because the ply won't move like the wood will and will prevent the wood from moving. If I have this wrong could you try to explain a little more fully and we'll try again.

[David Klug]

Steve you have it right about the grain moving on the top and sides but I'm wondering how I should handle the cross peaces that will hold the plywood shelving.

DK

[Steve Cox]

If you are talking about rails and stiles for a face frame the usual dimensions for these are 1.5" - 2" and shouldn't present a problem with movement (unless you have a whole lot of them in which case the accumulated dimension might need to be taken into account)