[ATM] BK7

[drewclan at aol.com]

Not to usurp Francis' question with a distraction, but with the demise of Pyrex I believe that BK7 in the non-refractor grades is going to become more common as a mirror substrate for ATMs in the 12.5 inch and below sizes. Does anyone know of a source for it? 

To stay on topic, perhaps Francis should make his 8" BK7 blank into an RC secondary ;) Jay in CT

Francis wrote:

I have a great piece of BK7, eight inches plus diameter, an inch thick. 
I need to do something with it. 
Maybe a Maksutov corrector?