Jeff Tsai on sun 14 apr 02
Okay, this is not about saggaring in electric kilns or anything like that,
but I have a question and would like suggestions for a kiln I will fire
tomorrow.
I loaded a saggar kiln; it's a small hardbrick gas kiln with a hardbrick
saggar box in the middle. I've been having probalems with this kiln ever
since I rebuilt the interior cause the bricks were falling in. I used to get
these beutiful oranges and pinks and tan/yellows. Suddenly, I rebuilt it and
it was all black and white and bleah. (bleah being whatever ghastly color
you
can think of)
Anyway, I finally got fed up the the whole thing and tore down the entire
deal and started over. I redirected flames, cleaned out the saggar box
(which
I used to just lay stuff in and layer up vermiculite and sawdust and
colorants and salt) and put in shelves. I stopped using almost any
vermiculite and use very little sawdust now. I use the same colorants
(copper
carb, cobalt ox and Red Iron ox.) with seaweed and salt.
Anyway, I did a firing in a box that was now much more open with losts of
open air inside. The colors came out pretty good. I got a lot of reds and
blues. BUt I miss those oranges and pinks.
I figure the reds are developing from copper fumes mostly, and so here's my
question. Anyone know enough about chemicals and their reactions to
atmosphere to tell me if I reduce the kiln more heavily during my firing, or
less heavily during the firing, if that might change that red into a pink or
orange? Any totally unbased answers are welcome.
-jeff
Dannon Rhudy on mon 15 apr 02
... stopped using almost any
>vermiculite and use very little sawdust now. I use the same colorants
(copper
>carb, cobalt ox and Red Iron ox.) with seaweed and salt.
......colors came out pretty good. I got a lot of reds and
>blues. .....if I reduce the kiln more heavily during my firing, or
>less heavily during the firing, if that might change that red into a pink
or
>orange?.....
I assume that you are talking of low-fired saggars.
The reds are likely reduced copper. Unreduced, the copper
will make green flashing (usually fugitive, however). The pinks
and oranges are likely from the salt fuming. Sometimes you
get it , sometimes you don't. Saggar fired work is unpredictable.
You've noticed that. It can become a bit more predictable with
practice. Try not to use too much salt - it can cause spalling,
eventually, if you do.
regards
Dannon Rhudy
| |
|
