Glue, or no glue

[Allen Hough]

Deacon's Bench (dimensions overall about 30" wide, 18" deep, 36" tall), nearly ready for glue.

We're in the mountains of Colorado, at 8500', very low humidity indoors or out.

Sides - solid maple (edge glued), about 18" front to back x1" thick
Seat - solid maple, 18" front to back, 30" wide, 1" thick. Dadoed into sides
Below seat are two webs, of poplar, 2"x3/4" by and dadoed into the sides.
Back is spindles above the seat, and a panel below.
Spindles go into an arched curved top on the back, of maple, (about 1" thick x 3" high) tenoned into the sides.

Do I glue these dadoes full length? I'd think so, but a friend is raising a question about movement, expansion, etc. If I don't glue full length of each dado, what holds the box together? I've not been planning to use any fasteners.

Comments and questions welcome. No pictures yet, but can provide if needed.

Allen

[Jamie Buxton]

So the sides are solid lumber with the grain running up-and-down, and the seat is solid lumber running side-to-side? That is, the cross-grain direction on all three pieces of wood is front-to-back? If so, they all should breathe the same way, and you should be able to glue them without risk.

However, if the bench is built the way I've described, you have another issue to deal with. All the glue areas in the dado will have end-grain on at least one face. Glue doesn't bond well to end-grain. I'd build it with some additional means of fastening the seat to the sides -- for instance, Miller dowels.

[Alan Turner]

Done carefully, through wedged tenons would look nice in this application. But it may be too late for that.

[frank shic]

allen, you'll definitely need another method of securing the joint besides just the dado and the glue or IT WILL FALL APART over time and use. one option is to run pocket screws through the bottom but you have to make sure that the screw doesn't poke through on the other side.