Dado depth question

[Rick Moyer]

This will be a small bookshelf made from solid walnut. The sides will be 3/4" thick, but the shelves and dividers will be 5/8". Shelves will be 11" deep by 23" wide, with vertical dividers midway.

1. Should I dado the sides for the shelves to a depth of 1/4" or 3/8"?

Several shelves will have dividers top and bottom (remember these are 5/8" thick).
2. What depth should the dadoes for the dividers be? I"m thinking 1/8" depth leaving 3/8" between. These will mostly be in line with each other, so support shouldn't be an issue. Should they be even shallower, or 5/16" (1/3)?

[Kent A Bathurst]

This will be a small bookshelf made from solid walnut. The sides will be 3/4" thick, but the shelves and dividers will be 5/8". Shelves will be 11" deep by 23" wide, with vertical dividers midway.

1. Should I dado the sides for the shelves to a depth of 1/4" or 3/8"?

Several shelves will have dividers top and bottom (remember these are 5/8" thick).
2. What depth should the dadoes for the dividers be? I"m thinking 1/8" depth leaving 3/8" between. These will mostly be in line with each other, so support shouldn't be an issue. Should they be even shallower, or 5/16" (1/3)?

Rick - any of those options are fine, IMO. If I was doing it, I'd likely go with 3/8" + 1/8", for no particular reason.

[Dave Zellers]

How are you attaching the shelves to the sides?

Regardless, none of my dados would be more than 1/8", probably less on the dividers.

[Dave Zellers]

Also- if you have the ability, I would make the dividers thinner, say 3/8".

Are you doing blind dados?

[Howard Acheson]

The rule of thumb is to make the depth of dados no more than 1/2 the thickness of the board. Most would make 1/4" - 3/8" deep dados on 3/4" stock. For your dividers, 1/8" depth would be fine.

[Bob Wingard]

I used to go half way (3/8"), but I found some sheets warping at the dado, so I cut it down to 1/4" ... no warping and it's simpler to measure .. just add 1/2" to the inside measurement. The 1/4" seems plenty strong.

[Mike Zilis]

I think the general practice leans toward making the dadoes too deep. Don't rob the strength from your side supports. A 1/8th to 3/16th inch deep dado would do quite well.

[Dave Zellers]

I think the general practice leans toward making the dadoes too deep. Don't rob the strength from your side supports. A 1/8th to 3/16th inch deep dado would do quite well.

Z power! Just kidding- hope that's not taken as obnoxious. :)

I don't think I've ever done a deeper dado than 1/4" on anything.

The reason I asked how the sides were being attached to the shelves, is because if they are to be screwed and plugged, a 3/8" dado and recessed screw hole would leave very little material. 1/8" is plenty if it's screwed. Go 3/16" if you're just going to nail it.

[Rick Moyer]

How are you attaching the shelves to the sides?

Regardless, none of my dados would be more than 1/8", probably less on the dividers.

just glue


Also- if you have the ability, I would make the dividers thinner, say 3/8".

Are you doing blind dados?

Yes,blind dadoes. Wish I had seen your thinner divider comment before I calculated all the dimensions and made a story stick:(.

[Dave Zellers]

Well then, with no mechanical fasteners, I think I'll backtrack and go with 1/4" dados. Be aware that gluing end grain is different. Brush on a coat first, then coat all the other surfaces, then coat the end grain again before assembly. End grain soaks glue up like a sponge.

[Rick Moyer]

Well then, with no mechanical fasteners, I think I'll backtrack and go with 1/4" dados. Be aware that gluing end grain is different. Brush on a coat first, then coat all the other surfaces, then coat the end grain again before assembly. End grain soaks glue up like a sponge.
Good idea. I think I knew to do that but I'm glad you reminded me. Thanks.