On 5/25/2021 7:01 PM, bob prohaska wrote:
Jim Wilkins wrote:

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It's really hard to tell without handling the pan, but perhaps the edges of
the bottom have been stretched larger than the center. Making many narrow
bends sequentially can do that, since the metal stretches to accommodate
being bowed out. If the center was larger the edges would be stable and the
bottom would bulge and be in/out bistable. Hammering around the center
against a solid steel block might stretch it enough to remove the twist,
though judging where and how much to hit is tricky, an acquired skill. An
auto-body planishing hammer with a smooth face is neater than a ball pein.


Are you saying the bottom of the pan needs to be stretched, as in given
more area, to relieve the stress? I can do that, though it won't be pretty.

I tried simply straightening the flanges I'd bent, and the twist promptly
vanished. But, of course, the pan was now too wide. So I cut the offending
flanges mostly off with a pair of snips. The twist returned. Looks like the
twist is intrinsic to the pan and was somehow restrained by the flanges.

It's really tempting to think that forming what remains of the top flange
will flatten the pan bottom, but I can't visualize what it'll take.
Is that what you mean by:

Clamping the metal between two wood
blocks below the bend line and pounding on a third block pressed down
against the bend line is simple, neat and effective.

Thanks for writing!

bob prohaska


I was indicating the ANGLE between the edge you worked on and the bottom
is not identical for the entire length. If originally 90 degrees, part
is not 88 degrees and part is not 92 degrees. That will translate in to
warping of the bottom of the pan.
Paul