Re: [ATM] Removing perforated center

[Pete <lenses@adelphia.net>]

Hi Bill,
Your suggestion of submerging it into a bucket of water should work to 
some extent.
Unfortunately I've done the same thing and ended up using my trusty old 
screwdriver/hammer to remove plaster.
Can you block it up (hold it securely) and use a smaller core drill to 
put holes into the plaster?
Not sure if you have the room to do this. I have some small diameter 
core drills your welcome to borrow.
Or just use a small diameter regular drill bit.
This might be a bit safer.
Boil the water! (just kidding here but it might work quicker) We always 
like to try new things and get surprised if they work :)
Good luck,
Peter Nance, Jr.
lenses@adelphia.net

Bill Marriott wrote:
> 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
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>   

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