ATM rounding the edge

[Ina Ron Lippard Renaissance Reproductions <renrepro@surfglobal.net>]

    Dear List,
   There is a way to true up a mirror blank before you begin to grind 
it.Take it to a stone shop that deals with granite. They have equipment 
that will round out your glass.Failing that,try this.Go to Braxton and 
Bragg online. They sell 1/2" straight line diamond router bits for rough 
edging. Coupled with a 'rub-collar' you can rig up a template that you glue 
to the blank.A piece of 1/2 pine the right OD will work.With a trickle of 
water running over the blank,use your router to finish up what the glass 
foundry missed.Take light cuts until you have a nice even machined surface 
to the blanks edge.The blank will be nice and round if you circle-cut it 
using a pin and board arrangement on a table saw.Or the same rig that turns 
under your router. Block up the router so the wood passes underneath the 
base. Lower the bit for each  pass until you complete the template.
good luck,Ron