In , Victor Roberts wrote:
On Thu, 23 Jul 2009 22:14:05 +0000 (UTC),
(Don Klipstein) wrote:
SNIP to edit for space
Meanwhile, even soda lime glass is not that much of a conductor at
200-300 degrees C.
I have heard of HID lamps requiring any metal supports to be isolated,
to avoid problems with electrolysis of the glass bulb. I imagine this
problem involves amounts of current low enough to not be a shock hazard.
On the other hand, I have seen glass heated to the point of being soft
conduct impressive amounts of current (several milliamps, possibly more)
at a few kilovolts. I do not know what kind of glass was involved -
either soda lime or a cheaper flint glass, probably soda lime.
- Don Klipstein )
There's an interesting demonstration that can be done with a
rod of soda lime glass. If it is connected to a source with
the appropriate voltage output and current capability, and
then heated, it will conduct enough current to sustain the
temperature required for conduction when the external
heating supply is removed. I'm sorry to say I don't know
how much voltage is required to do this on any particular
size rod of soda lime glass.
I do remember seeing somewhere on the Web how to melt a soda bottle (or
was it a beer bottle?) in a microwave oven. The glass bottle to be melted
required a hot spot pre-heated with a "blowtorch" / "propane torch" or the
like, to temperature that I visually estimate to be in the 800's degrees C.
It appears to me that soda lime glass that hot achieves conductivity and
resistivity suitable for being sufficiently receptive for heating by a
microwave oven.
=========================
Disclaimer: I sense that this is adventurous usage of a microwave oven,
attempt to do such only at your own risk of damaging your microwave oven or
burning down the real estate that such microwave oven is in/on and
injuring/killing life forms in/on such real estate including loved-ones,
friends and pets by starting a fire.
- Don Klipstein )