Just Plain Bill
Kerf
Imagine yourself
the man on the street taking a survey. If you were to ask a random group of
pedestrians the meaning of the word “kerf”, how many of them do you think would
know the definition?
It’s a little
word buried in the treasure trove of useful and useless knowledge I’ve acquired
during my seven decades of living.
I’m taken back to
a time when I had the opportunity to teach woodshop for an eighth-grade class
in my very first year of teaching. I’d been leading playground programs in
several of the more rural and agricultural parts of my county, and, as I’d been
interested in transitioning from youth work to teaching, this opportunity came
up. I’d completed my student teaching and welcomed my group of 20 eighth
graders on day one of the school year.
(A note on the
class size: I was assigned a self-contained class of 20 students, five students
each from the “bottoms” of the other four classes. The reasoning behind this strategy
was that by relieving the four classes of remedial work, the rest in the other classes
would flourish. More in a later post on the results of this controversial “experiment.”)
In addition to
teaching all the core subjects to my eleven girls and nine boys, I was asked to
offer a woodworking class. I did know a little about the craft, having been
taught by an uncle who was an experienced shop teacher. Fortunately, my uncle had introduced me to what’s called the kerf, the amount of
wood that is cut away due to the width of the saw blade. (It’s also what ends
up as the sawdust.) So right off the bat, my class and I were spared a common problem
that can occur while woodworking, best illustrated in the following true story:
The minister of my church
told me about the time he learned about kerf. He was cutting some wood, using
the piece he’d just cut to measure the succeeding piece of wood. When he’d cut
all 12 pieces of wood, he noticed that each piece he’d cut was just a tiny bit
shorter that the preceding piece, only about 1/8th of an inch, but
it resulted in his next 11 boards being just a tad short. Do the math and you
can see how much shorter that last cut piece was compared to the very first. Not
good!
So if I’m ever asked the
definition of a kerf by that man on the street taking a survey, in a trivia
contest, or even on Jeopardy, I’m ready!
