The Science of Rented Mules (aka Chisels)
Sometimes when I
write, I come to a question that paralyzes me – and I cannot continue
until I get it answered. As a newspaper journalist, I was trained to
“write my way around the problem,” which probably is one reason I don’t
work for newspapers anymore (the other reason: there aren’t any
A few days ago I was writing about chisel handles.
Blah, blah, blah. Tang, socket or Japanese. Yadda, yadda, yadda.
Ferrules, bolsters and hoops. Gabba, gabba, gabba. Best types of wood
for a handle.
This is a good question: beech,
hornbeam, maple, white oak, hickory, something else? And what can one do
to delay a handle from splitting? Use a mallet that is softer than the
handle? A mallet that is harder than the chisel? Perhaps the mallet
So every evening I’ve been diving deep into the
research available on the impact resistance of woods. What makes some
woods better for beating and others not so good? I have yet to turn up
much science that is really helpful to me. There is a lot of data out
there that relates to baseball bats, but most of that relates to woods
being beat on the side grain or face grain – not the end grain.
There is this article
from the Royal Society that has some interesting data, but it doesn’t
really answer the question when it comes to end grain impacts. Bruce
Hoadley’s book “Understanding Wood” deals with wood failure parallel to
the grain, but not about wood impacting wood. Where does the energy go
during the impact? What happens if the chisel handle is softer or harder
than the striking tool?
I must be missing something out there.
So if you are an impact nerd, could you drop me a line? I’d really like to get this sorted out so I can get on with my life. Thanks in advance.
— Christopher Schwarz
Resources Related to this Post
• David Charlesworth’s DVD “Chisel Techniques for Precision Joinery” is excellent. We need more information on chisels in the world.
• Here is one of the best free links ever. The Forest Product Laboratory has just released its 2010 “Wood Handbook.” You can download the whole thing for free from the U.S. Forestry Service’s web site. Go here. Bookmark it.