Re: ATM RE: Gluing Blanks Together

[Andy Saulietis <iss@pvtnetworks.net>]

Re,

>>As a little side note here, the glassblower types use only one kind of glass
>>(brand and type) with thier work and all glass is welded together rather
>>than glued and even then, they still have breakage of complex stuff from
>>quick changes of temp.  There are some "warm glass" forums and a fair bit of
>>websites out on webland for further edification.
>
>Agree, this is essentially what i do, a thin (5/8") meniscus,   16" dia. or
>larger is fuse bounded to a "flotation" support of the same glass,
>to a 1/2" thick backplate, works great !
>see picture in my signature,
>and yes, i did break quite a few before getting it right  ;v)
>jean-guy

I think Zerodur was originally developed to be used for
blanks that were to be fused together and still retain
its low CTE/stress properties.

One thought I had on 'glued' sandwich blanks was to apply
the glue only on part of the surfaces, and fill the rest
of the gap with fluid that had good thermal conductivity
properties, thus reducing the thermal gradient stress.

At Ball Aerospace, we were assembling multi element
star tracker lenses using optical UV cure epoxy cements.
These would sometimes fracture under thermal test; a special
epoxy had to be used which was flexible enough to cope
with the thermal differential & different CTE glasses. These
lenses were < 1.5" diameter!


   

Andy Saulietis
ISS Enterprises
39 Silver Fox Trail
Mayhill NM 88339
505-687-3067 voice
505-687-3021 fax, call voice or e-mail to set up
e-mail: iss@pvtnetworks.net