Bruce Girrell on wed 26 may 99
Not saying this is an old subject, but the first article in Vol. 1 No. 1 of
Ceramics Monthly (Opening the Door to Copper-Red Glazes by Harding Black)
deals with local reduction of copper sulphate by silicon carbide. He
provides two cone 06 recipes. Each uses 1 "part" (per cent?) tin oxide, 1
part copper sulphate, and 0.2 part silicon carbide in addition to the other
ingredients.
Black then discusses various high fire copper red reduction glazes, some
using copper filings, a technique he tried after one of his students
scrubbed a pot with a "Chore Girl" scrubbing pad and got bright red spots in
the glaze where there were bronze fragments from the scrubbing pad.
These glazes are surprisingly complicated - up to 12 ingredients (16
ingredients if you count all the stuff that goes into the Bernard Leach
copper pigment).
It's kind of interesting how these subjects just keep making the circuit.
There has been a recent thread on Why cone 10? The _second_ article in that
same first issue, entitled Contemporary Pottery and High Fire by Daniel
Rhodes, tackles the same subject.
Those interested in the influence of women potters may be interested to note
that the cover story in the first CM issue was about Adelaide Alsop
Robineau, whom the magazine credits with "[saving] American ceramics from
portending oblivion and [causing] the National Ceramic exhibitions to be
founded." You may cringe a bit, though, when a few paragraphs later we get
the following sentences: "...no American all-ceramic exhibitions existed.
The American ceramist had yet to 'arrive.' Arrive *he* did when Mrs.
Robineau entered her now famous Scarab Vase..." (emphasis mine). Wish I
could post a picture of the vase.
It took CM until June of that year to get to the topic "Are Lead Glazes
Dangerous?"
And by December, guess what? "Local Reduction Copper Reds" by Edgar
Littlefield. Four cone 9 recipes using 1% tin oxide, 0.2% copper oxide, and
0.2% silicon carbide and three more cone 04 glazes using 1% tin oxide, 0.14%
copper carbonate, and 0.3% silicon carbide.
Bruce "the more things change, the more they stay the same" Girrell
| |
|
