[ATM] Removing perforated center

[Bill Marriott <bmarriott@pacbell.net>]

Hello;

I just finished a 8" flat with a center hole, held in place with plaster 
of paris.

Looking to release the core with out downgrading the glass, so re coring 
I think is too risky, so;

Since I have a variety of chemicals here in the optical shop, any 
suggestions as to what might attack the plaster, but not the Pyrex.

I have HCL, nitric acid, acetic acid, KOH, NH4OH, (the latter two would 
probably etch the Pyrex), TSP,

For now, just going to toss it (haha) into a tank of water and let it 
sit overnite, to see how far the water will soften the plaster.

Any suggestions are greatly appreciated

Bill Marriott
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