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specific gravity of glazes

updated tue 2 nov 04


John Bandurchin on mon 1 nov 04

We use a hydrometer (hygrometer?) to get our glazes at the right =
density. We took a hygrometer used to test the s. g. of fermenting wine =
and wrapped lead tape around it until it was suitable for glaze. We =
them put it into a container of glaze that we knew was at the right =
density and marked the spot. These hygrometers are probably available =
in many stores - we got them from a wine-making shop. Of course it =
doesn't tell us the s. g. but we don't really need to know that. If you =
use one of these, it's a good idea to make two and mark them both, since =
they're breakable.

William Melstrom on mon 1 nov 04

Floating glass aquarium thermometers make great "relative" hydrometers. Put
one in glaze of the "correct " density, and mark it with a sharpie. It
takes a very small (shallow) amount of glaze to use. They are prone to
breakage, so buy several, and always have at least one that is correctly
marked in reserve.
If you want to get really fancy, aquarium supply stores also sell
combination floating thermometer/hydrometers for salt-water use. But, they
are longer, and require a deeper sample.

William Melstrom