Glass sparking? Is there an situation which could/would cause soda lime or boro to spark?

Im asking this question because in another NG someone has said you
should not use glass balls in a ball mill (Pyrotechnic manufacture ball
mill) because the glass could spark and ingnite the pyrotechnic mixture
being milled.
I have never heard of soda lime or boro sparking before. It sounded
suspect to me.

Thanks
Matt

On 20 Nov 2005 00:06:34 -0800, "Matt" wrote:

Im asking this question because in another NG someone has said you
should not use glass balls in a ball mill

What does Lloyd reckon ? He's the man who'd know.

Yes, glass will hold static electricity.
The two most obvious examples are
1) using a fur to stroke a glass rod and then touching the rod to
something and getting a spark - this was the original demonstration of
static electricity.
2) The disks in a rotating disk static lightning machine are glass (with
metal take-off lines).
Whether glass in the ball mill will cause problems will depend on what else
is going on (powder, other insulators, dampness and conduction) but the risk
seems reasonably high.
--
Mike Firth
Furnace Glassblowing Website
http://users.ticnet.com/mikefirth/
"Matt" wrote in message
oups.com...
Im asking this question because in another NG someone has said you
should not use glass balls in a ball mill (Pyrotechnic manufacture ball
mill) because the glass could spark and ingnite the pyrotechnic mixture
being milled.
I have never heard of soda lime or boro sparking before. It sounded
suspect to me.

Thanks
Matt

Doh, My brain was half asleep. To much work and up to late. I forgot
to even consider electric discharge. I was stuck thinking about sparks
produced when something is ground such as metal.

Matt