[ATM] Quartz for a first mirror?

[Dave and Connie <dmatt@frontiernet.net>]

I have been looking into getting a blank to make my first mirror.  Either 
an 8" or 10" would be more than adequate for my needs and I will probably 
go with something in the f6 - f7 range.  I will use it in a take down 
Dobson for easy storage.

I have pretty much narrowed it down to either pyrex or quartz.  Up to 8" 
the pyrex seems slightly cheaper but at 10" the quartz is significantly 
cheaper than pyrex.

The upside of quartz are that it is a bit lighter than the pyrex and it is 
affordable in 10".
The downside of quartz is that it is harder and thus slower to work (or so 
I have read).
The temperature expansion difference isn't really all that important at the 
sizes that I am dealing with.

Pyrex is a bit quicker to grind but is considerably more expensive for a 
10" blank.  It will also make a heavier to transport scope but at an 8" not 
enough difference to matter.

I am leaning toward a 10" -10.5" quartz blank.  One of the ones that is 
scrap from the semiconductor industry.

What are the reccomendations for a beginner on using quartz?

Is a .8" thick quartz blank going to be too flexible for a beginner?

Dave

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