On Aug 27, 10:38 am, (Richard Casady)
wrote:
On Wed, 27 Aug 2008 08:07:19 -0400, "jamesgangnc"
wrote:

You sit with a piece of thick round glass in your lap

I have read the few books on the subject, and perused the telescope
making column in Sky and Telescope regularly for decades, and I have
never heard that one. Sounds like doing it the hard way. You creat an
immovable stand, somewhere in the area of waist high, and fix the tool
to it. Occurs to me you might make the stand from concrete blocks. The
mortar doesn't have to look pretty. When finished chisel it apart, or
just break it up with a big hammer.
You walk around it while rubbing the mirror blank over it. Never heard
of any other way. You have to keep good control of the grit, or a
piece of 180 will show up while you are doing the final figuring. You
keep your clothes away from things, so that you don't transfer coarse
grit into a fine grit stage. I bet Edmund still has stuff of interest.

Casady

I built a stand weighted down with two concrete blocks. When I was
13, I ground a 6" mirror from an Edmund kit and I think the Edmund kit
was crap to comparison to what I have now. Edmund's largest abrasive
was 180 Aluminum oxide and they didnt send enough of that. By
comparison, my three largest abrasives now are #80, 120 1nd 180
Silicon carbide, MUCH faster. You do not use Al2O3 till the finer
grades.
My wife who is the usual clean freak around the house marvels at my
sudden interest in cleanliness in the utility room.