....
grinder and a straight edge. Then I draw-filed it. Then I struck it (filed
straight along the length.) Then I cross-filed it, then struck it
diagonally. All of this filing took less than five minutes. It's pretty
darned flat.

This is the same method I have used in the past for flattening cylinder
heads on lawnmowers, BTW. And don't tell anyone, but I also used it to

I didn't reply here earlier cause I knew iggy wanted smooth not flat.

I'm curious. When I need both, I've used your procedure, only with stones
and kerosene. It does take a lot of time. Good idea or am I wasting time?

Karl