Kate Johnson on mon 6 dec 04
Hi Ron...
>
> Illmanite is like rutile but with more iron - so it will produce
> attractive
> specks in a glaze if the glaze is melting enough. If not melting enough
> the
> specks are not very interesting.
Hmmm...I wonder what's up with my red oxide not melting more? I understood
it was fine for an earthenware glaze, but I surely did NOT expect big old
black chunks sticking up above my glaze surface!
I don't think the ilmenite would do that, because it's pretty fine and very
granular, but still...will it melt at earthenware/low fire glaze temps, or
should I forget it?
>
> It will tend to settle out quickly to constant stirring is necessary.
Part of my problem too with the red oxide, I'm sure. (Long day, concrete
floor, aching knees made me work way too fast to get done. I KNEW I should
have washed that glaze off and started over...)
>
> Illmanite comes in different mesh sizes - some is just powder and can be
> used like rutile but will produce a darker colour because of the extra
> iron.
>
> I would not be surprised if the grains would be excellent seeds for
> starting crystal growth.
Neat!
Thank you!
Best--
Kate
Ivor and Olive Lewis on tue 7 dec 04
Dear Kate Johnson,
Ilmenite is classed as an infusible material in Dana's Manual of
Mineralogy. This means it will melt just as easily, or if you like,
with the same degree of difficulty, as Quartz. But finely divided
Ilmenite will dissolve in molten Sodium Carbonate.
If Red Iron oxide is not dissolving in your glaze perhaps your recipe
has insufficient material which will melt and provide the necessary
solvent action. Alternatively, you may need to take the glaze toa
higher temperature.
Best regards,
Ivor Lewis.
Redhill,
S. Australia.
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