Logan Oplinger on sun 23 nov 03
Dear Processing Gurus,
This past weekend I've been ball milling dry raw materials for making test
glazes. After about 6 hours of milling, a large portion of the each
material is stuck (caked) to the inside of the mill jar.
I am using a two quart porcelain jar w/ 3/4" diameter porcelain balls. The
charge I use by volume is 1/3 material and 1/3 balls. The mill is a
recycled hobby gem tumbler with one set speed, about 100 rev. per min.
All three materials are caking. These are:
Crushed bottle glass, volcanic ash, & borax.
Could the problem be excessive moisture (humidity here is usually 75-90%),
improper diameter of grinding balls, or improper operating speed of the
mill (tumbler)?
Tonight I will try pre-drying these materials in an oven at 250 deg. F. for
about 2 hours.
I can switch to using a smaller 1/2 inch diameter porcelain balls.
I cannot increase the speed of the mill if that is the problem unless I
increase the diameter of the rollers. This will decrease the mechanical
advantage between the rollers and jar.
Thanks, in advance,
Logan Oplinger
Another Tropical Island
Where we were just missed by typhoon Lupit!
Richard Aerni on mon 24 nov 03
Logan,
It's been a while since I've ball milled my glazes (just moved the d***
ball mill to the new studio, though), but I always milled them wet, not
dry. I'm sure you will get better advice from those who do it regularly,
but you might want to try it wet.
Best,
Richard Aerni
Rochester, NY
>Dear Processing Gurus,
>
>This past weekend I've been ball milling dry raw materials for making test
>glazes. After about 6 hours of milling, a large portion of the each
>material is stuck (caked) to the inside of the mill jar.
>
>I am using a two quart porcelain jar w/ 3/4" diameter porcelain balls. The
>charge I use by volume is 1/3 material and 1/3 balls. The mill is a
>recycled hobby gem tumbler with one set speed, about 100 rev. per min.
>
>All three materials are caking. These are:
>
>Crushed bottle glass, volcanic ash, & borax.
>
>Could the problem be excessive moisture (humidity here is usually 75-90%),
>improper diameter of grinding balls, or improper operating speed of the
>mill (tumbler)?
>
>Tonight I will try pre-drying these materials in an oven at 250 deg. F. for
>about 2 hours.
>
>I can switch to using a smaller 1/2 inch diameter porcelain balls.
>
>I cannot increase the speed of the mill if that is the problem unless I
>increase the diameter of the rollers. This will decrease the mechanical
>advantage between the rollers and jar.
>
>Thanks, in advance,
>
>Logan Oplinger
>Another Tropical Island
>Where we were just missed by typhoon Lupit!
>
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