If you turn bowls you typically are shooting for a "fair curve"
a continuous curved line, with no bumps or hollows. Achieving
a fair curve on a turned piece may appear easy - one continuous
final cut. But the eye, and the hand, can percieve when the curved
line is not quite right, though identifying WHERE the problem(s) is/are
is not easy to do when the "not quite right" is small.

Now it's easy enough to see if a "flat" surface is in fact flat. Lay
a known straight edge on it and with a light behind it, look along
its bottom edge. If you see light then the surface is low there
- or the surface is high on either side.

And for circles, a similar method can be used to identify where
something is out of roung.

But a method for checking to see if a curve is "fair" is not so
obvious - until you see a method that does the job.

John Brugo, of the West Bay Area Woodturners, shared this
method at the July meeting of the Silicone Valley Woodturners.

Get ye to your local crafts supply shop or hobby shop and
pick up a hot glue gun glue stick - one of the long ones - 10
to 12" long. Hold one end on the bottom of your bowl and
bend the rest onto the profile of your piece. Sight along the
bottom of the glue stick looking for light coming through.
If you see any light shining through you know where the low
spot is and then know where wood must be removed. The
glue stick can be used to check the inside of the bowl as
well.

Simple, cheap, and effective. Like all great ideas, it's so
very obvious - once you see it done.

Thank you John. Yet another reason for joining a turners
club.

charlie b