Heidi Haugen on sun 22 aug 99
Am wondering about the use of chrome oxide as a colorant in functional
glazes, couldn't find much in the archives. I have just switched from
cone 10 red to cone 6 ox and am just beginning to test new glazes. In
"Electric Kiln Ceramics" by Zakin, he lists chromate compounds as
toxic. I am curious if this is just for the potter as a raw material,
or if chrome has been shown to leach. I will send my glazes to Alfred
for testing before selling but am curious if I should just forget about
chrome as a colorant and switch to copper carb for my green. Many
functional glazes in CM list chrome as a colorant and it was also
present in the cone 10 glazes that I was using.
Can I just substitute copper carb straight across for chrome?
Any help will be appreciated.
Heidi Haugen
Dave Finkelnburg on mon 23 aug 99
Heidi,
You need to do some test tiles. In my limited experience at cone 5-6
ox. copper gives yellow-greens and chrome gives much cooler, blue-greens. A
strong chrome glaze, for example, will yield a "Hunter Green." I've never
seen anything like that with copper.
By the way, copper leaching isn't so good for one's health, either.
Dave Finkelnburg
-----Original Message-----
From: Heidi Haugen
To: CLAYART@LSV.UKY.EDU
Date: Sunday, August 22, 1999 7:30 PM
Subject: chrome safety
>----------------------------Original message----------------------------
>Am wondering about the use of chrome oxide as a colorant in functional
>glazes, couldn't find much in the archives. I have just switched from
>cone 10 red to cone 6 ox and am just beginning to test new glazes. In
>"Electric Kiln Ceramics" by Zakin, he lists chromate compounds as
>toxic. I am curious if this is just for the potter as a raw material,
>or if chrome has been shown to leach. I will send my glazes to Alfred
>for testing before selling but am curious if I should just forget about
>chrome as a colorant and switch to copper carb for my green. Many
>functional glazes in CM list chrome as a colorant and it was also
>present in the cone 10 glazes that I was using.
>Can I just substitute copper carb straight across for chrome?
>Any help will be appreciated.
>Heidi Haugen
>
| |
|
