Thursday, February 10, 2011

boxes from readers

Every once in awhile, I am contacted by readers with boxes to share. The tea box ws made by John Gasser for his Daughter-in Law, and you can see from her reaction that the box is a success. The Pin and Earring chest was made by Les Riddell.

I had the following question about wood movement:
I have constructed a small jewelry box recently and have some wood movement concerns. The box is 11” wide (the front and back), 6” deep (the sides), and 5.5” high and is made of 1/2” cherry. The grain runs in the same direction for all of the panels. The sides have vertical rabbets on each side  of 1/4“ depth and 1/2” width. For the bottom, I cut rabbets of 1/4“ depth and 1/2” on all four sides.

I am worried that the wood on the bottom and top of the box will expand enough the sides or front/back. I live in the Boston area, so there is some summer humidity, but it’s not like I’m sending the box to south Florida. Should I be concerned?
Wood will almost always expand and contract, even when you have heated and air conditioned space. It will not expand or contract any significant amount in length. My rule of thumb is to allow for both expansion and contraction, with the expansion often being the more destructive effect, pushing parts apart at the corners. So I generally allow 1/32 to 1/16 in. expansion space per 8 inches of board width. This can vary some by species and will vary more dependent on the condition of the materials and their storage and working conditions with regard to humidity. If your storage and working conditions are on the moist side, or during the moist season, build looser than you would be inclined during the driest of conditions. You can take each board as a science experiment, worthy of investing a great deal of time, or knowing what wood does, just take your best shot. You will get more done if you take your best shot.