Wood movement in small boxes?

[Eric DeSilva]

Among my other projects, I wanted to take a stab at getting used to a Leigh dovetail jig. I have some 4/4 bloodwood and 4/4 walnut, and was thinking about just putting together a small dovetail box with bloodwood front/back and walnut sides. Maybe something like 5"W x 6"L x 4"H. I'm also going to take a stab at resawing both the woods, so I'm hoping for 3/8" stock.

I can obviously rabbet a top and bottom in--probably bloodwood for the top, 1/4" ply for the bottom (was theoretically planning on felting the interior). Which brings me to my question... How do people address wood movement in small scale items like this? My natural inclination would be to do a 3/16" dado for the top and leave 1/16" gap on the front/back of the top. Maybe just glue the center of the top panel? How do other folks do this? I seem to recall seeing tops that looked solid wood just glued to the top and proud of the top all around; are people just counting on limited wood movement?

[Wade Lippman]

Normally you would put the top in a dado rather than a rabbet; leaving a 1/16" for movement as you say. No glue should be necessary.

I built a desk organizer, deliberately putting the curly maple drawer fronts in with the grain going the wrong way because it looked better. I figured if it turned out to be a problem I would replace them. They are very tight, but have never moved. Likewise I have an 18" strip of CC that I measure every now and then. It has never moved.
If you are in an airconditioned/humidified house the humidity doesn't change much and wood doesn't move.

[Gary Breckenridge]

I kind of figure that you can easily go to about 10" on crossgrain joints if the wood is thoroughly dried. It also depends on the wood and the kind of construction used: dowels, quality glue or screws. Do a test joint and then put it in the shower and then the oven. Try crossgrain joints of 2, 4 anb 10" to see how they work. You can also do a rabit with a floating panel.:cool:

[Brent Smith]

At 4" wide pieces I wouldn't even consider wood movement to be an issue. I've made tons of boxes this size and have never, to my knowledge, had any problems with it.