Joe, A number of things could be the cause. Here's my input.

Is the grain direction perpendicular or parallel to the spindle of the
lathe?

If perpendicular, this is normal 'bowl mode'. Hollow the inside from the
outside in and make sure you are cutting with only the right hand
(leading) side of the gouge. Don't let the absolute point or left side
of the gouge cut. Also, try to feed the gouge more in a lateral arc
through the piece or sliding along the rest. Avoid an in-line push.

If parallel, 'spindle mode', work from the center to the edge. Make sure
your cutting is done with the leading edge as you pull it through. If
the trailing edge catches, kaboom.

Then again, maybe it is one of the other dozen possible reasons causing
the problem. Let us know how it works out.

David

wrote:
Hi all,

I'm new to turning (so that may be the problem here...). I've been
practicing on some mahogany I had around and have gotten fairly
successful. Well, I picked up a block of walnut and haven't been so
lucky with it. I'm trying to hollow out a shallow bowl and my
fingernail gouge quickly catches and throws the bowl off the lathe.
This is bad. I'd really appreciate some help here. Here's what I've
observed:

1. The stock is being held by a nova chuck expanded into a recess in
the bottom of the bowl. It's held pretty tightly.

2. My 1/2" fingernail gouge is brand new, sharpened with a tormek
jig. Sure seems sharp to me. I've never used it before, so technique
could easily be the problem.

3. The walnut is very dry.

4. If I use a scraper, I can be pretty successful with the hollowing.

5. If I use the gouge, it catches brutally and throws the bowl.

Any thoughts?

Many thanks,
Joe

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