Follow-up question to Rules of thumb for wood movement
bndsley
| Posted in General Discussion on
So if I make a box say 5×8 or 6×9 or there about (just your run of the mill jewelry box) and glue a solid piece of wood in a rabbet around the top should I be concerned about wood movement? In other words the top edges of the sides would frame the inserted piece of wood with (hopefully) no gap. What I’m asking is if on this smaller scale is wood expansion/contraction still a concern?
Thanks,
BobE
BobE
Replies
Yes, even in a small box wood movement can be an issue (unless you are using plywood for the top). One of the best designs for small boxes that allows for wood movement can be found in FWW #246 (April 2015).
The previous posts did not cover the key point that with environmental changes wood moves more in some dimensions than in others. Most of it occurs at a tangent to the growth rings (tangential movement), less occurs perpendicular to the growth rings (radial movement) and even less happens along the length (longitudinal movement). The authoritative book on this and many other relevant subjects is "Understanding Wood" by R. Bruce Hoadley.
What joeyboy said. However, it also depends on the species of wood, type of cut (quarter sawn or flat sawn or rift sawn), and the environment where it will live. If it stays in a climate controlled home, you will likely never see any movement in something that small. The safest way is to use veneered plywood or mdf for top and bottom.
If I make a box, I like to led the lid and base float in a rabbet.
Can't say I've made enough (10 or so) to be an expert but they don't seem to move much. I'm just too lazy to glue.
On the base or bottom I generally use plywood which as I understand it is okay to glue which I do. This also helps strengthen the box. I've read about floating the tops/bases but don't entirely understand it. Doesn't it rattle when picked up? Don't the seems tend to shift?
Yes and yes. They will rattle and shift if they don't fit snugly. That is the purpose of frame and panel construction. It allows the panel to move with seasonal changes while the frame stays a stable size. Also, the grooves must be deep enough to allow for that movement, of course. There is a product called "spaceballs" (I think that is the name) that goes into the bottom of the grooves to help keep the panels from rattling if they are too loose but they still allow for seasonal movement.
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First. You will likely get better answers if you start a new thread rather than attaching your question to someone elses. Second, be sure to post some photos and some dimensions of your cabinet.
Thank you! Will do. Need to figure how to start new thread