Re: ATM Hoggin out the 18.5

["Andy Mail" <amail@scimar.com>]

As a member of Bob May's mirror grinding group, I can attest to his
assertion that grabbing any old hunk of steel and grinding away is just
fine.
I'm working an 8" f5.6 and started by hogging with a galvanized steel 2"
pipe cap from Home Depot.  Nothing magic about the size (fits my hand well)
or the material.
I used it successfully both right side up and upside down.  I took a hacksaw
and made several cuts across the face of the cap for when I ground face
down.  This allows the carbo to hang around at the interface instead of just
getting pushed off the glass.
I hogged and hogged until I had ground all the way to the edge, the sag was
about where I wanted it, and the overall shape was roughly spherical.  If I
thought to myself that one area looked "underdone", I would just work on it
until I felt warm and cozy.
This part of mirror making is *really* rough and dirty.  Things don't even
begin to get touchy until you have made a tile tool and are starting the
fine grinding.
I would point out that if you can find a local (or semi local) group you
might be more comfortable.  I know that's the case with me.  I have a dozen
or so classmates of varying experience with which I can learn and share the
experience.  Not to mention Bob's invaluable tutelage.