Wednesday, October 29, 2008

Perfect Timing

It really isn't often that one can bask in the glow of perfect timing, but getting the roof on my new woodshed, the day before the first snow sure felt good!

My most recent rocker design allowed me to try many things that I've always wanted to try. One of the most surprising and simple of the new technologies is the square peg. It just doesn't seem like it would work, driving a square peg into a round hole and ending up with a clean square showing. But it does!

The process begins with the drill bit. I've been told that this works best with bits that are 3/16" or less. The one that I used on my chairs is a bit larger and worked fine. Once the bit is selected, it's time to shave some square pegs that are just a hair larger than the bits diameter (this will account for the hole being slightly larger than the bit).

Once the peg is shaved square, I chamfer the end that will enter the hole first. On my second chair using square pegs, I drove the peg 1/8th" into a steel plate with the same size hole as the bit. This created a perfectly sized end to enter the mortise.

Below is an image of the pegs after being driven home. One has also been chamfered into a pyramid shape. At first I was surprised that the peg didn't split the mortised piece, but after doing it a few times, I realized that to do so, the diameter of the peg would have to be larger than the mortise. Because only the corner of the pegs are larger than the mortise, they simply compress as they cut their way into the corners of the mortise. By the time the peg is driven all the way in, all that you can see is the clean corners.

I highly recommend giving this one a try, if for no other reason than to stand back and be amazed that it works.
I've enjoyed seeing folks at my new showroom being drawn to the contrasting pegs. They just can't help but touch them, a fine result.


Anonymous said...

one of the issues I have when doing this is what to use to shave the square peg to a pyramid. I know that Brian Boggs actually made a knife with one side flat and the back side convex, so he could keep from making a mark on the leg. what did you use?

Scott Estepp

Peter Galbert said...

I ground a chisel with a slightly convex bevel and then put masking tape over the bevel up to about 1/16" away from the edge. This is not the most graceful of solutions but the rounded surface and masking tape are kind to the surface. If I come up with something better, I'll let you know!