Breadboard Ends

[James Jayko]

So I built a box to house a tool in my shop because why not practice dovetails. I made a simple lid from some flat sawn maple and I'm just thinking that it's certainly going to cup over time so I should take some precautions. Easy enough to do breadboards.

Two questions: given that this isn't a piano, would just domino'ing the breadboards to the end of the top be effective at maintaining flatness? Or is the integral tenon somehow more important thant I'm assuming? I figure its grains going different directions so they will resist cupping, but I'm not positive.

Second, the top is ~12" x 20". Is a 1 1/2 - 2" end sufficient? and if so, how long would you make the tongue? Is there some rule of thumb here?

I know that none of this is probably necessary, yes. Just a chance to do something different in the shop so why not!

[John TenEyck]

Sure, you can use Dominos to join the ends to the top, as long as you leave room for expansion/contraction with the outboard ones, and only glue the center one, just like is done on true breadboard construction. The downside of using only Dominos is you will have no stub tenon running the full width of the top, so it could cup between the tenons. Not likely, but that's why the stub tenon is used with true BB's.

I don't know of any rule for how wide the BB piece should be, but my guess is the 1-1/2 - 2" you are thinking about would be adequate. Aesthetics often is a deciding factor. And thickness plays a major role in preventing cupping so, at some point, the width of the BB is irrelevant if it's too thin.

John

[Justin Rapp]

So I built a box to house a tool in my shop because why not practice dovetails. I made a simple lid from some flat sawn maple and I'm just thinking that it's certainly going to cup over time so I should take some precautions. Easy enough to do breadboards.

Two questions: given that this isn't a piano, would just domino'ing the breadboards to the end of the top be effective at maintaining flatness? Or is the integral tenon somehow more important thant I'm assuming? I figure its grains going different directions so they will resist cupping, but I'm not positive.

Second, the top is ~12" x 20". Is a 1 1/2 - 2" end sufficient? and if so, how long would you make the tongue? Is there some rule of thumb here?

I know that none of this is probably necessary, yes. Just a chance to do something different in the shop so why not!

I made a cutting board with breadboard ends. I did a long dovetail joint with the end of the cutting boards having the 'tail' and the breadboard having the tail socket. Once I slide the breadboard end onto the cutting board I drilled a hole on the bottom of the board, center point of the joint and glued in a wooden dowel. The rest of the joint is left unglued for wood movement. This board is a daily use board, washing all the time, and I think i've given it a light sand and oiled it maybe 3 or 4 times in maybe the 5 or 6 years since I made it. So far, it's still flat. I didn't put feet on it and it sits flat on the granite countertop most of the time except for after a heavy wash where it is leaned up on edge to dry.

[Matt Day]

Dominos will work, but allow for expansion for all but the center one which can be glued both ends. The others should be draw bored.

[Gordon Stump]

My rule for the tenon/moritse is 1/3+ the thickness for the tenon.

[Bill Dufour]

I like the look of Greene & Greene bb end screw placement. horizontal screws parallel to the main top. No worry about screws being too long
Bill d

[Richard Coers]

If you hard glue and domino the bread board ends on, you will be guaranteed of a cupped lid. Wood moves in its width and the bread board end is cross grained. Solid wood only cups if there is a change in moisture, or you don't consider wood movement in your design.