Well, I'm back to the drill idea. Still gonna get heat on the sheet metal at slower RPM's, just take longer (x3). Sure would like to hear if anyone has used a drill with a shrinking disc.. there has to be.
Here is an 8" SS plate/cover:
Didn't know there were that many sizes for this item.
If anyone has pics of their fabricated disc, feel free to post; don't care if it's