Dave Finkelnburg on fri 2 jul 04
Randy,
Your question is tough to answer. You are using two materials that can
be highly variable, the Gerstley borate and the volcanic ash. Do you have
an analysis for the volcanic ash, or source information? Also, any idea how
old the Gerstley borate is?
Generally speaking, your test is probably more telling than any
calculation. Sounds like a decent glaze. Yes, it should be reasonably
stable, durable, and should fit some stoneware, probably will craze on some
porcelains.
Regards,
Dave Finkelnburg watching thundershower winds bounce the sunflower
blossoms in their wake
----- Original Message -----
From: "Randy McCall"
Sent: Thursday, July 01, 2004 8:36 PM
Volcanic Ash 25%
GB 25%
3134 10%
Custer Feld 10%
Kaolin 10%
Silicia 10%
Wollastonite 10%
100%
When tested to Cone 6 I got a nice smooth shiny clear glaze. Smooth to
touch.
Any comments on stability, expansion, etc? Combination of two glazes to
make one.
Randy McCall on fri 2 jul 04
The GB is recent, the VA does not have an analysis, it is also recent. =
I am sure it is not Mt ST Helens. =20
It has a very nice smooth texture that I like. I was getting some =
bubbles with the 2020 so that is why I added the VA/GB combo. I also =
did not like the VA/GB alone. Just tried it to see what I would get. I =
have JH's glaze software and the alumunia/silica ratio seems to be ok =
from what I can see. It is not a semi matt but close and shiny but not =
a bright shiny.
Randy McCall
----- Original Message -----=20
From: Dave Finkelnburg=20
To: CLAYART@LSV.CERAMICS.ORG=20
Sent: Friday, July 02, 2004 6:52 PM
Subject: Re: Question on this glaze? Randy McCall
Randy,
Your question is tough to answer. You are using two materials =
that can
be highly variable, the Gerstley borate and the volcanic ash. Do you =
have
an analysis for the volcanic ash, or source information? Also, any =
idea how
old the Gerstley borate is?
Generally speaking, your test is probably more telling than any
calculation. Sounds like a decent glaze. Yes, it should be =
reasonably
stable, durable, and should fit some stoneware, probably will craze on =
some
porcelains.
Regards,
Dave Finkelnburg watching thundershower winds bounce the =
sunflower
blossoms in their wake
----- Original Message -----
From: "Randy McCall"
Sent: Thursday, July 01, 2004 8:36 PM
Volcanic Ash 25%
GB 25%
3134 10%
Custer Feld 10%
Kaolin 10%
Silicia 10%
Wollastonite 10%
100%
When tested to Cone 6 I got a nice smooth shiny clear glaze. Smooth =
to
touch.
Any comments on stability, expansion, etc? Combination of two glazes =
to
make one.
=
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