Paul Herman on sun 20 jan 02
Hey Lewy,
All through this thread, I keep hearing a nagging question in my head.
Why calcine these shells? Why not simply crush them and use as whiting,
which is not water soluble. Calcining does not change the calcium that
is contributed to the glaze melt. When a glaze is fired, all the whiting
is converted to CaO in the firing. Are you calcining it in order to
convert it into a powder?
Paul in Doyle
Llewellyn Kouba on sun 20 jan 02
Hi! Paul,
Yes, I had read in an earlier thread to Clayart that the shells should be
calcined and I had thought they were a little on the hard side so I
figured- and not knowing better, I decided to do that. I calcined them in
my bisque kiln to 010. They did deteriorate fairly easy. I had put a mask
on and at turned my fan on at the spray booth and smashed them through a 60
mesh screen. They came out pretty fin and figured I would try them now on
some test tiles and see what happens in a glaze. Maybe they would
pulverize pretty well dry and as is but I didn't really give that a try and
figured it would be messy and dusty and just plopping them in a greenware
bowl and popped into the oven seemed so non labor intensive to me.....not
of course that that was the best way to go?
So I guess you could say I was calcining it to covert it into a more
manageable powder.
Llewellyn
At 09:47 AM 1/20/2002 -0800, you wrote:
>Hey Lewy,
>All through this thread, I keep hearing a nagging question in my head.
>Why calcine these shells? Why not simply crush them and use as whiting,
>which is not water soluble. Calcining does not change the calcium that
>is contributed to the glaze melt. When a glaze is fired, all the whiting
>is converted to CaO in the firing. Are you calcining it in order to
>convert it into a powder?
>Paul in Doyle
>
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