Tuesday, March 23, 2010

Using the Hollow Square Punches

Before starting give the punch a good sharpening. The sharpening cones available at Lee Valley are the correct angle for the inside surface.

Layout the location for the square hole.
Using a small square, center the punch on the layout.


Now lightly tap it in place to registers its position. Often the punch will stay put when you remove your hand - if not it is easy to relocate.

Now, using a bit that is 3/64" under the size of the square hole (3/8" square hole - use 21/64" bit), drill out the center. Use an ordinary twist bit for this and not a brad point. The leading sharp corners of the brad bit will catch on the inside of the chisel and damage themselves.

To finish off - strike the punch with the hammer to its final depth. Before removing the punch use the drill once again to remove most of the wood chips.

Remove the punch for a perfectly square crisp hole!


The Hollow Square Punches will be available from Lee Valley Tools very soon.
Use the product code 50K5920.
For more on the Hollow Square Punches see my previous blog.

Wednesday, March 10, 2010

Hollow Square Punches

As a furnituremaker, working in the style of Greene & Greene, I have chopped out more than a few square holes for ebony plugs. The accepted method for this has been to drill a round hole and use the chisel from a hollow chisel mortiser (hand held) to square up the holes. This has worked to some degree, but with limitations. One of those limitations being that a 3/16” hollow chisel was not available. Since I employ quite a few 3/16” square ebony plugs in my designs, this meant chopping out those holes by hand, with a lot of patience (and time).
This prompted me to design my own hollow square punch – not only because I needed a 3/16” size, but also one that is specifically designed to be hand held.
My early attempts did not meet expectations, but after a few tries, the new tool was actually outperforming expectations. Dozens of these were machined and made for me, by my friend Bob Hadley. Thanks BOB!
Once I had a working tool in hand, I submitted the idea to Lee Valley Tools. They liked it and turned it over to their R&D department. The Lee Valley folks made improvements and sent me the prototypes for testing. My friend George Knutson helped me run the punches through their paces. I then returned them along with comments and suggestions. We went through this process twice. I was greatly impressed with the Lee Valley R&D people – they really brought the tool to perfection!

















Later this month Lee Valley Tools will have available for purchase the hollow square punches in six sizes -3/16” - ¼” - 5/16” - 3/8” 7/16” - ½”.
Use the product code 50K5920 to check on the punches availability.
I will follow up soon with a blog that details the use of the punches.