I've only been turning for a bit more than 3 years, so I'll readily admit I've got a lot to learn. Here's something I've been wondering about, lately.

Context: I've been turning some larger bowls lately, using some larger wood pieces that I'd been saving until I acquired a bowl coring tool. I've been coring large maple, box elder and camphor pieces, getting 3 to 4 bowls per log-half. And now I'm beginning to work on some of those rough core-outs. The bowls range from 18" (rough size), down through the teens.

At the same time, I've been trying to make my wall thickness (for the final turn) thinner than I've been doing up to now. I'm trying to get a good surface at 1/4" wall thickness, but having some problems.

What I've found is that I do better getting thin walls with the smaller (diameter and height) bowls. I think that is due to having greater vibration problems, as the bowl gets further out from the centerline of the lathe, and further out in front of the chuck. I've tried applying a gloved hand to the outside of the bowl while I'm shaving the inside wall thickness down, but one-handed tool control (the other being outside the bowl) is a challenge. I end up getting little "divots" along the inside surface of the bowl, particularly out close to the rim.

I think part of this is due to impatience. I'm thinning the walls down, working from rim to bottom of the bowl, in increments of an inch or two. That way, the thin portion being worked on is not extended far out from the remaining thick wall, and is thus more stable, as I work in. But sometimes I move on to the next inch or two before getting a really smooth final cut on the part just thinned, meaning I have to come back later, at a point that vibration can be really bad because the whole wall, rim to bottom, is thin.

Anyway, here are my questions:


  1. Have others also experienced this problem, or is there something I should be doing to avoid it?
  2. What thickness of wall do you try to achieve, for bowls of, say, 17" diameter, and is that different from wall thickness for a 12" bowl?


Thanks.

Robert