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Old 01-28-2021, 12:07 PM
mark g mark g is offline
Metal Shaper of the Month, April 2011, December 2012, May 2016
 
Join Date: Nov 2010
Location: Southern VT
Posts: 357
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Hi John,

I hope that my postings weren't in any way discouraging or overly confusing. My enthusiasm overshadows my ability to simplify, sometimes.

Here are a few basic things that I've found to be helpful.

The edges of a circular bowl shape will always lay flat on the table if you push down hard enough on the edges. As you push north and south down, east and west will rise up in reaction and vice versa. You may have to over-adjust (bend) a piece enough by hand or over a suitably shaped object to make it stay.

An elliptical bowl will react similarly, but eventually the pointier ends of the ellipse will suspend the bowl off the table. It would take reshaping or trimming off the pointier ends or un-shaping the middle of the bowl to get the edges down to the table again.
Saddle shapes react differently. When you press down on north and south, east and west follow downward.

If you hammer up more shape into a dish than you want, all is not lost; you can hammer it back down by supporting the metal well from underneath, with a softish support flatter than the dish's crown, or maybe an unsolid support like a shot bag, and knocking it down from the top with a flat faced striking tool.

When the metal is pressed between two objects like a hammer and dolly, or two air hammer dies!, the object with the least contact area to the metal tends to affect the greater change, so when you want to knock the metal back down, support it well from underneath and just tap it back down. If you were to use anything other than a flat faced striking tool, you risk inverting the crown or creating other interesting wrinkled effects that might only be useful in a different situation!

If this is helpful, I have more. Good luck, and thanks for your compliment on my work.
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