Re: ATM Big scopes

[jgmoreau@lino.com (Jean-Guy Moreau)]

>>
>> Why pay for thick glass if you fuse it, use 1/4", it is cheap, hey Richard !
>> You can then heat at 100 deg. per hour and save a lot of electricity.
>>
>>
>
>Jean
>Weren't you the one who had all the failures in fusing 1/4 inch plate
>glass and stated he would never use it again - as in finishing a 18 inch
>that cracked in your hands right from the oven?
>
>Ric


Hi Ric,

Right, but it had nothing to do with the use of 1/4" plate, or does it ?
Someone on the list was kind enough to help correct my
annealing procedure. I am still experimenting... that is
what learning is all about. I remember Richard's advice about
using glass from the same batch to rule out the possibility
of variations of TCE and how little a difference could build
up catastrophic strains.

All was not failures as I made successful 14 and 16" ribbed
blanks that are now working telescopes, and I believe I did not
say my last word on this. However fusing 1/4" plate into
solid blanks 2" thick is easy up to 24" so far, with a nice
moulded curve that lets you start fine grinding in less
than an hour on #80, not bad I think !

There is a very real possibility of fusing usefull large blanks
out of cheap plate glass, maybe ribbed ones too, its up to us
to discover how. (Just daydreaming)

Tell us about your latest fusing experiments...

Jean-Guy