Tim Roberts on tue 24 sep 96
Hi All,
What is praseodymium? Does anyone have experience with this oxide that you
would share? TIA
Always learn.
Tim Roberts
KEMPB on tue 24 sep 96
Hi Tim,
Preaseodymium gives a very reliable yellow colour in glazes under
both oxidation and reduction but it needs at least 10% or more in a glaze
to have any real strength of colour. I understand it is not sold in the oxide
form but rather as a stain in combination with zircon.
My students use it in their Cone 7 oxidation glazes with great results...but
it is a little pricey.
Regards
Brian kemp. Singapore
kempb@nievax.nie.ac.sg
PJLewing@aol.com on wed 25 sep 96
Praseodumium is the metal oxide used to produce lemon yellow stains. It
produces not as intense a yellow as vanadium or antimony, but unlike
vanadium, you can use it in reduction, and unlike antimony, you can use it at
higher temperatures than about ^010. I have used praseodymium stains under a
clear glaze at ^10 reduction to get a pale lemon yellow. It is a metal
oxide, so it's not exactly good for you, but it's not nearly as deadly as
either vanadium or antimony.
Praseodymium is pretty much always used in the form of a stain, with
zirconium and silica. About 5% will produce the strongest color. Any more
than that will not produce any stronger color. Your only control of
intensity of color will come with different base glazes. Sorry I can't be
more specific there, but I know that some bases produce stronger color than
others, I just don't remember which. One thing I have noticed is that in
small batches of praseodymium yellow glaze, a very small amount of
contamination with another color of glaze will significantly muddy the yellow
color.
Mason makes several praseodymium yellow stains- the dark lemon yellow one is
a bit more intense than the others.
Keep Testing.
Paul Lewing, Seattle
http://digitalfire.com/magic/lewing.htm
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