Telescope Reviews: melting pyrex for blanks

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mark cowan
Vendor (Veritas Optics)

Reged: 06/03/05

Loc: salem, OR

Re: melting pyrex for blanks new

[Re: Mark Harry]
#5599024 - 01/01/13 01:20 AM

Quote:

Instead of doing a displacement of volume, just calculate volume instead. I used this to identify a pyrex blank that was moulded in a KzFS4 mould with those initials on the glass. I came out to within 3 places of the decimal point of pyrex value---close enough.
M.

Yup. I did this to ID a suspected Zerodur blank (oh, like the color isn't a giveaway -

- but they've come in all shades). Measurement and an accurate scale gets to digits.

Best,
Mark

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FlorinAndrei
scholastic sledgehammer

Reged: 09/28/10

Loc: California

Re: melting pyrex for blanks new

[Re: danjones]
#5600135 - 01/01/13 06:49 PM

Dan, how many watts (or amps) are required by the 17" kiln at peak temperature?

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John Carruthers
Skiprat

Reged: 02/02/07

Loc: Kent, UK

Re: melting pyrex for blanks new

[Re: mark cowan]
#5602328 - 01/03/13 03:40 AM

or immerse the suspected Pyrex in vegetable oil, if it 'disappears' it's pyrex (or something with a similar RI).

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danjones
member

Reged: 09/26/12

Re: melting pyrex for blanks new

[Re: FlorinAndrei]
#5607519 - 01/05/13 11:24 PM

hi florin. thanks for the interest. i'd have to go out and look at the label of the kiln, but i'm sure it's requires 30 amps for peak temp topping out at near 2300 degrees. for melting plate glass, it can be just melted enough at 1700-1725 or so. melting broken chunks or strategically cut chunks in a stack, needs more 1800. other substrates like pyrex and others need more, but well within my kiln's max. it needs 230v to operate fully, but requires more technology than the onboard temp control. glass is finicky, and the temp needs to be controlled precisely. i'm working on a ramp/soak controller to exactly control the kiln's temp operation. the ramp up heat and soak times need to be controlled, especially to well anneal the glass and take out any strain, even in the thickest of blanks.

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