Re: [ATM] Microwave heating of glass

[Ian Williams <i.r.williams@bristol.ac.uk>]

So, how does this sound for the next draft of the microwave powered 
glass furnace method?:

Assumptions:
1) That fire-brick is a very poor absorber of microwave radiation.  If 
anyone here can test this by trying to heat a mug of water enclosed in 
fire-bricks I would be very grateful.
2) That plaster of paris/Alumina is also a poor absorber of microwaves 
and is suitable for making a refractory mould for glass.
3) Suitable lab-safety is followed at all times.

Method (draft 2):
* Purchase/reclaim a microwave oven with 'microwave stirrer' type of 
magnetron, fire-bricks, glass of desired quality, several SiC sharpening 
blocks, and Plaster of Paris/Alumina to make a mould.
* Make a block of plaster of paris/alumina of dimensions 10"x10"x5" with 
a cylindrical depression in the top surface, of diameter ~8" and depth 2".
* Machine fire-bricks to make an enclosure that completely fills the 
space of microwave leaving enough room inside for the mould and SiC 
blocks.   Don't forget to fire-brick line the base of the microwave 
underneath the mould.
* Break up required amount of glass into pieces of size ???? cm^3.
* Place microwave where, if it catches fire, the fire won't spread. e.g. 
outside.
*  Place fire-bricks, mould, broken glass and SiC blocks into said 
microwave.  The SiC blocks could be:
    a) all around the mould, thus absorbing all the microwaves, or,
    b) only on the sides of the mould away from the magnetron, thus 
allowing the glass to absorb microwaves directly too.
* Set timer to somewhere around 15 minutes, press go and stand well back.

If you can spare some more criticism of these ideas, I would appreciate 
your time.

Thanks again,
Ian


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