[ATM] Does exposed Pyrex lose polish over time?

[artbianconi@blast.net]

Pyrex  is amongst the most popular materials in most chemistry labs 
I've been in. Precisely because it is relatively impervious to 
thermal shock and caustic solutions 

Unless your shop has the atmosphere of Venus, I seriously doubt 
anything has happened to it's surface.

On second thought. . . . . . it's probably pitted like hell and 
coated with green mold. Why not send it to me! I'll figure out (sic!) 
a use for it that will keep it out of the sun.

Art


Hello all, been away for a while.

It’s spring and time to think of telescope making again after an 18 
month hiatus.  So I’ve got this 20” Pyrex mirror with a nice, 
uncoated figure  that’s been stored face up in the shop for 1.5 
years.  A quick rinse and it  looks good as new.  I want to send it 
to the coater.

Now I know the answer is almost certainly a resounding “NO,” but I 
was  wondering if the bare Pyrex might have lost a bit of shine in 
this idle 18 months of direct exposure to the atmosphere.  What think 
you?  Does Pyrex oxidize, or react with the airborne products of 
human respiriation, smog, gas heaters, swamp coolers, air pumps, 
dust, etc?  Which of these might be harmful, and over how much time?

I’m feeling a strange compulsion to make a lap and give it a few 
polishing swipes, but you all know what that can lead to...please 
help me avoid this stupid mistake!

Bill T.


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