Tom Buck on mon 11 nov 02
David, others:
I did follow-up testing of the pots I glazed with my revised raku
lustre recipes. I put the pots out in the bright summer sun for three
months continuously. The only change that occurred was the slow darkening
of the bright penny glaze-- it moved closer to the red matt lustre, which
was unaffected. Use Recipe No. 7 of Tomats Red if you want a durable matt
red (needs extra reduction to get a solid red). If you want a glossy red,
use No. 8.
Just as silver spoons, et al, will darken if exposed to household
vapours, so will the bright penny slowly change with exposure to bright
light (the surface stops vapours but not photons). the Copper metal
re-oxidezes to red copper oxide, the colour of C10R copper reds.
I reported this data to Ceramic Review in a letter in 1996/7 but
never did post the report on digitalfire.
peace. Tom B.
Tom Buck ) -- primary address.
"alias" or secondary address.
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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