Breadboard Ends

[iSawitFirst]

I've been looking at a lot of G&G lately and as we all know, they use a lot of breadboard ends. Most projects I've seen have no pegs through the end boards leading me to believe the longitudinal boards are glued to the end board. I assume each longitudinal board is glued only in the center of the tenon so the connection acts the same as a pinned connection. Either way, I don't understand the principal. If the longitudinal boards are placed tight against each other swelling would stress the "pinned" connection more and more as you go to the ends. This swelling would be additive across the width of the top placing the most stress on the end connection. G&G have the Ebony spline on the end that's supposed to evoke some sort of "structural-ness" but its really just for show (I've always thought it looked a little silly to my analytical mind).

Can anyone explain to me how the breadboard end allows for movement?

[thewoodwhisperer]

Well there's no shortage of improperly-made breadboard ends. Bottom line is if you restrict movement, you could eventually have problems. So the key is to lock down the board at the center of the panel, while allowing for movement toward the ends. And you still need to hold the board tight against the panel across the entire length, so either using screws in oversized slots or a drawbored dowel (with an elongated slot) works quite nicely.

[adamking]

All your really well made bread board ends are using a drawbore system. Depending on the width of the top, the boards have large tongues or tenons milled on each end. These are slid into corresponding mortises in the bread board end caps. Then, a hole is drilled into the bottom of the end cap and through the tenon that's 1/16" forward from center. Then you hammer a wooden pin that draws the joint tight and locks it in place. Also, the mortises are typically 1/4"-1/2" wider than the tenon to accommodate wood movement.

Aside from the decorative element, the breadboard system is designed to keep tops flatter than if they were left as a slab top. The earliest examples are found on bread cutting boards. Hence the name.

[Pete Bennett]

Hate the bastards! Avoid 'em when ever I can. The greatest drawback is when the free running boards expand or contract they will either go beyond the cleat or shrink inside it. leaving ugly steps. Recently I made a solid Oak table 1500mm wide about 5 feet over ten feet long the client insisted on cleated ends (breadboard ends) I tried to explain that on a table this width 1% of movement would mean 15mm or five eights inch movement. I returned after one year and removed 6mm from each corner of the cleat. I hope the table has settled now. Incidentally the way I was taught to do them is like this:- Take the cleat and run a deep groove from one end to the other stopping about 1" from each end and one third the thickness. At the centre form a deeper mortice about half inch narrower than the centre board. Make sure that all the other boards are a good tight fit in the groove but don't try tapering them in the belief that driving them on will keep them tight, it won't. As the cleat dries and shrinks they will be more loose than if the sides are parallel as the shrinking timber will slide away and the widest part of the slot will move down and away from the tongues, if you can follow me. Drill a hole for a peg in the centre mortice keeping it as close to the inner edge as safely possible. Next drive the tenon in tight, make a mark in the tenon centre using the same drill through the pre-drilled hole, withdraw the tenon and drill the hole about 2mm, a little over a sixteenth, closer to the shoulder than the mark. Now cut a slice about quarter inch from each side of your tenon to allow for movement in the mortice. Glue up all the boards forming the top and once set and cleaned up etc. Making sure the entire length of the tongue is about quarter inch shorter at each end than the groove in the cleat carefully drive the whole together, if you want, though I never do, you can put a dab of adhesive on the middle of the centre tenon. Once the whole is up tight drive a peg through the centre hole this will give everything a little more pull as it's known as a 'drawer peg' If you've made a completely straight cleat and got a completely straight edge you should have a very tight joint that hopefully will stay that way. To be honest I find that careful choice of timber to begin with and very, very careful preparation and jointing coupled with plenty of buttons holding down to a really solid apron frame keeps most tops pretty damn flat.

Hope this is of some help to some body

Pete

[Rutabagared]

I added a twist using the Festool Domino. I posted about it on the FOG (Festool Owners Group). Feel free to bash my technique as I'm not 100% sure it's sound . . . time will tell.

Joe

[Pete Bennett]

I added a twist using the Festool Domino. I posted about it on the FOG (Festool Owners Group). Feel free to bash my technique as I'm not 100% sure it's sound . . . time will tell.

Joe

Hi Joe had a good look at your post, Frankly I can't see any major problems arising unless some glue squeeze out took place within the joints that you would not see. It just goes to show the advances we are now making with modern techniques. I don't own a domino machine and have yet to see one in action, but, from what I've read they look truly impressive. I would guess that your method probably takes about half the time it would normally take doing the conventional thing. The sort of thing that suites me, cos I rarely do anything in any facet of my life conventionally. Which incidentally pisses off the authorities no end!

Pete

[flairwoodworks]

For a dining table or coffee table, breadboards are usually fixed in the center and have elongated holes at the ends. However, in certain cases, such as a desk or side table, where the tabletop would be against a wall, often the back is fixed and the center and front have elongated holes. The tongue, of course, runs the length (or almost the length) of the breadboard to resist warpage.