Bill,

Ruth's advice is good. It is an easy way to diagnose what is happening.

If you were scraping the rim, then I doubt if you would get a giant catch.
If scraping, do it lightly.

If you were cutting across the rim, which I suspect, the dynamics of a catch
are very subtle. To explain what might have happened, try this experiment.
With the lathe OFF, hold a skew point straight into the rim (just touching)
with the handle parallel with the spindle's axis. Orient the cutting edge
vertically, with the long point down. Now raise the handle slightly so that
more of the skew's cutting edge contacts the bowl rim. Now, turn the bowl
by hand. The sharp edge of the skew will make a line all the way around the
rim if it is EXACTLY vertical. If it is even the tiniest bit tipped toward
you, the skew edge will spiral out. If it is tipped away from you, the skew
will spiral in.

When starting a gouge on a spinning surface, the gouge's cutting edge acts
exactly like this until the bevel is rubbing. When the tool is laying on
its side with the flute pointed to the left or right, there is a tiny piece
of the cutting edge that is vertical and will track correctly around the
bowl's rim. Even the slightly misalignment forward or backward will cause
the tool to rapidly spiral in or out and possibly cause a catch. The trick
here is to be firm with the tool when introducing it into the rim. For that
brief amount of time that there is no bevel rubbing, the only support the
tool has is your hand on the tool rest. Make the flute dead flat as you
can, then be firm on the start of the cut. Assuming that you are cutting
away from yourself, if the tool is tipped back a bit, the tool will tend to
kick away safely from the work. If the tool is tipped away from you, the
tool will tend to dig into the work and cause a catch. As you learn where
that exact spot is, err on the side of a kick out rather than a dig in.
Then you can make tiny adjustments on your hand positions until you hit it
just right.

Hard to explain without showing you, but I hope it makes sense.

Joe Fleming - San Diego
==============================




"Ruth" wrote in message
...

Bill wrote: ...snip...."so I used a bowl gouge more or less on its side
as I had done successfully for hollowing the inside, and I approached
the inside edge very carefully, but I got a catch"....snip....
**********************************
Bill,

Without seeing what you're actually doing, it's quite difficult to
correct your approach.
I'm not going to go through a long description of proper tool handling
(I'm sure others will do that better).

Here's what I do when I *think* I'm using a tool right and it goes
wrong: hold the tool as you were but with the lathe OFF. Hand turn
the bowl and watch how the tool edge is reacting. You could have not
turned it at enough of an angle, you want the edge to be more scraping
than cutting as it would when hollowing the inside.

Hope this helps.
Ruth

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