Sunday, October 23, 2011

Breadboard Ends

Desk with breadboard ends fitted
Desk with breadboard ends fitted
When using wood boards for a desktop, particularly oak, I usually tongue and groove the edges for strength before gluing them together.  To make the ends of the desktop attractive, and help keep the top flat, I add a board to each end and these are called "breadboard" ends.
The plain end of a tongue and groove desktop looks like this:
Plain end of tongue and groove construction
Plain end of tongue and groove construction

Even without lumber marks this doesn't look very nice.

I begin by cutting the end boards about 1" longer than the desktop depth.  The process of grooving the boards makes the groove flare slightly outwards at one end.  The extra length lets me cut the flared part  off - otherwise there would be a visible gap where the tongue and groove meet.

The next step is cutting grooves in the edges of the boards that fit on each end.
Groove cut in breadboard end
Groove cut in breadboard end
I use the same groove cutting plane that I used to tongue and groove the boards in the desktop.  This is an English plane, set for 7/8" thick boards.  The standard in America is 3/4", so the groove is closer to one side than the other.  When the desktop is finished I think it looks better for the thin side to be on top.
Chiseling mortise ends
Chiseling mortise ends
After the groove is cut I make it deeper to create a mortise in the end board, 3 inches in from each end.  I make the depth 1 1/8", the maximum setting for the hand router I use.  I set an adjustable square to this to test the depth and cut out a 2 inch starter slot at each end of the mortise with a 1/4" mortise chisel.
Routing mortises to depth
Routing mortises to depth
Lining up the two breadboard ends with their thinner tops together I use the router to cut down to the right depth, adjusting the depth stop about a quarter turn after taking a cut in each slot.
Cutting the tenons
Cutting the tenons
The tenons on the ends of the desktop are cut using a skew filister plane.  The nicker in front of the blade makes a clean crossgrain cut through the fibers of the wood.

I use a clamped piece of scrap lined up with the tenon shoulder as a double check that the filister plane doesn't creep over the shoulder line. 

The depth of this cut is easy to check because the tenons will be the same depth as the tongues that join the boards together.  When the grooved edge has been cut through to expose the tongue all the way to the shoulder of the tenon, the depth should be correct.

The tenon at each edge is shortened to the depth of the groove 3 1/4" in from the edge.  The breadboard end mortises were cut 3" in from the ends of the breadboard, so there will be 1/2" clearance to allow for wood movement in the top.
Fitting
Fitting the breadboard end
The fit of the breadboard end to the desktop tenon is refined with a shoulder plane until it can be tapped on firmly with a deadblow mallet.

You can use a glued dowel from the underside to secure the breadboard end.  If you want to have the possibility of removing the breadboard end, for example to make finishing easier, the joint can be secured from underneath with a figure of 8 fastener and a couple of screws.  As the fastener has countersinking on alternate sides, I countersink one hole from the other side so both flathead screws sit flush.

1 comment:

  1. Well written; shows the marks of a craftsman. I notice that the author uses antique tools.

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