Alisa and Claus Clausen on thu 7 sep 00
Recently at my supplier, he told me that I could use Bismuth nitrate =
instead of Silver Nitrate and get the same colorful effect in raku =
glazes. It comes with all the same hazard precautions as silver nitrate =
but the price was less than half.
In USD it would be equivilant to
1 gram Silver nitrate at 17 cents
1 gram Bismuth nitrate at 4.8 cents.
I do not know this material and wonder if the glaze gurus, raku guru =
would like to comment on Bismuth as a sub. for silver nitrate,=20
if it is a satifactory sub,=20
and or if there are downsides.
Best regards,
Alisa in Denmark
Tom Buck on thu 7 sep 00
Alisa:
Bismuth subnitrate in a Raku mix tends to yield silvery,
mother-of-pearl colours rather than gold. This lab reagent soon goes to
Bi2O3 in the kiln, and this oxide melts at 820 C so it would be fugitive
if overfired (900 C). Silver nitrate soon become silver oxide Ag2O and it
too is fugitive, perhaps moreso than Bismuth Nitrate, so Ag2O is also
sensitive to overfiring. Whoever wishes to obtain, Gold Lustre in a Raku
firing should work on this lustre alone and should not mix it with other
lustres in the kiln. I recommend light to medium reduction to a (C010 or
lower) fired pot.
bfn. peace. Tom B.
Tom Buck ) tel: 905-389-2339
(westend Lake Ontario, province of Ontario, Canada).
mailing address: 373 East 43rd Street,
Hamilton ON L8T 3E1 Canada
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