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sieved out ingredients

updated mon 2 nov 98

 

Diane Woloshyn on fri 30 oct 98

Have had a problem with two commercial glazes that I ordered dry shipped.
They were two different glazes from the same manufacturer and came at the same
time. When I mixed them up, they had very small lumps that would not blend
even with a blender. So I sieved them both to remove the lumps. When they
were applied to the pots they ran like a scalded cat. Am assuming what was
sieved out was silica. When I talked to the manufacturer, they said they had
never had a problem before, that it was probably silica, and send a sample.
Was put on hold and ignored. Yes, they lost a customer. BUT my big question
is: when you sieve something out of a wet glaze, it will not achieve the same
results, how do you measure the sieved out ingredients to replace them? Do
you rinse the ingredients, let them dry, and reweigh? Any suggestions would
be greatly appreciated.

Diane Florida Bird Lady

Brad Sondahl on sun 1 nov 98

Lumps in glaze are sometimes lumps of the mixed glaze, most
often lumps of Zinc Oxide that have absorbed moisture. If
they were silica, removing a bit shouldn't cause the glaze
to run unduly. If the glaze is truly running off the pot,
first ascertain that you have the correct firing temperature
(and that they sent the correct glaze). If those are
correct, you should be able to break down most of the lumps
by swishing over the screen with a rubber spatula. What
doesn't go through after that usually is not a large enough
percentage of the total to affect the mix. If you buy a
commercial glaze, there is no way of knowing the
ingredients, thus no way to know what one might replace the
lumps with.
--
Brad Sondahl
Sondahl homepage http://www.camasnet.com/~asondahl/
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Re:
my big question is: when you sieve something
out of a wet glaze, it will not achieve the same results,
how do
you measure the sieved out ingredients to replace them? Do
you
rinse the ingredients, let them dry, and reweigh? Any
suggestions
would be greatly appreciated.