How large a box lid before I need to worry about wood movement

[Andrew Pitonyak]

I purchased some chisels that came in a wood box. The box is roughly 12" x 18" x 2". The sides rae finger jointed solid wood. The top and bottom are plywood glued to the top. The sides where then cut and a hinge attached.

I recently saw plans for a toy chest done in a similar manner..... The top was glued on, no account for wood movement.

I am planning on making a few wood boxes (all dimensions less than 2', and I am unsure if I can simply glue a top in place or if I need to do something different such as a floating panel.

This beautiful walnut box looks like it is glued in place
http://www.sawmillcreek.org/showthread.php?169575-Walnut-Box

I found a few brief comments, but nothing definitive
http://www.sawmillcreek.org/showthread.php?98836-larger-jewelry-box-lid-construction

[John TenEyck]

If you use veneer plywood or MDF for the top/bottom there's no need to worry about wood movement. If you use solid wood then you do. If you made a box like your chisel box but used solid wood for the top then something's going to give (i.e. split or break apart) over a period of time if the box goes through substantial seasonal humidity changes. A slab top, on the other hand, won't be a problem because it is free to expand/contract, although it might cup. A frame and panel type construction will solve all those concerns.

John

[Jim Matthews]

I provide a 1/16" space all around panels larger than a sheet of notepaper.

I like the synthetic rubber bumpers as spacers. They keep things from rattling.
One note - the panel and groove should be the same shape - a tapered panel will wedge into the groove and can blow out the thinnest section.

[Andrew Pitonyak]

I provide a 1/16" space all around panels larger than a sheet of notepaper.

Note to self..... leave 1/16". OK, that makes sense. I will probably cut the grooves and then fit the top and bottom this weekend. I do have some spacer balls, I just need to find them. Hopefully they are small enough to fit in a 1/4" groove.

[Howard Acheson]

The amount of wood movement is determined by the width of the board or panel, species of wood and the range of change in the relative humidity in the area where the item resides. Of course, this is talking about solid wood. Plywood has no movement for all intents and purposes.

In my area, a 24" wide solid panel of oak could have up to a 1/4" or more of seasonal movement.

The only way to really answer your question is to know the answers to the above questions. When you have that info, go to the "Shrinkulator" at http://www.woodbin.com/calcs/shrinkulator.htm and plug in the variables. The output will give you the info you need.

[Jim Neeley]

Not the answer to "how wide" but a comment on an attractive way I saw very wide panels handled...

This last weekend I looked over some dining room tables while I was checking out couches at a local Amish furniture store. They had a beautiful hardwood table that was about 12' long and 5' wide, made of solid ash. Their technique was to install breadboard ends and make the top from ~3" wide tongue and groove panels, affixing each "slat" in place with a walnut peg. It was visually striking!

I've been considering experimenting with brass or copper pegs on future projects myself.

[Richard Coers]

Not the answer to "how wide" but a comment on an attractive way I saw very wide panels handled...

This last weekend I looked over some dining room tables while I was checking out couches at a local Amish furniture store. They had a beautiful hardwood table that was about 12' long and 5' wide, made of solid ash. Their technique was to install breadboard ends and make the top from ~3" wide tongue and groove panels, affixing each "slat" in place with a walnut peg. It was visually striking!

I've been considering experimenting with brass or copper pegs on future projects myself.

That's all good if the wood only shrinks. But if it expands, something is still going to give. Unless they pegged through slots in the end tenons, and have room in the ends of the breadboards.