scott@explorethejourney.org on fri 2 dec 05
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So some friends and I did our first pit-fire a few weeks ago, and I wanted to get some info on the
results. I added about 3 or 4 pounds of salt and about 3 pounds of Copper Carbonate. I had a lot
of nice reds and some oranges and yellows come out and of course a lot of black. My question is
what effect does the salt and CC actually have as far as adding color.
scott jarrett
jackson, ms
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Taylor from Rockport on fri 2 dec 05
Holy crapola, Scott. Three pounds of Copper carb. That must have been one
nice sized pit. Lucky.
Copper carb will give different colors depending. Greens when you don't
get good reduction and if you're nice to it maybe some red with reduction.
I've had great luck with mirracle grow getting reds. Same pot got greens
from copper carb sprinkled on surface of pot. (didn't shovel it in like
you did). I still haven't been able to figure out what the salt is doing
in my pit, but it is supposed to give salmons as well as other colors like
yellow. I think I'll wash my pots with Fe OX and Cu Carb this next pit.
Keep up the pit firing 'cause there ain't much better then a fire-filled
hole in the ground.
Taylor, in Rockport TX
http://www.wirerabbitpots.blogspot.com
On Fri, 2 Dec 2005 09:40:16 -0600, scott@explorethejourney.org
wrote:
>So some friends and I did our first pit-fire a few weeks ago, and I wanted
to get some info on the
>results. I added about 3 or 4 pounds of salt and about 3 pounds of Copper
Carbonate. I had a lot
>of nice reds and some oranges and yellows come out and of course a lot of
black. My question is
>what effect does the salt and CC actually have as far as adding color.
Sam Kelly on sat 3 dec 05
Depends on how hot the pit achieved, what you fired it with(wood?), the
salt and oxides can be sprayed on the pots before putting them in the pit.
http://home.exetel.com.au/pottery/pottery/pitfire/pitfire/index.htm
Sam- Australia
Bonnie Staffel on sat 3 dec 05
Hi Clayarters,
One thing to watch out for is the action of the salt on your pit fired
pots. It will eat and crumble away terra sig and even the clay body if
certain conditions are in place. I believe that moisture has a big part
to play in this result. Whether your wood has some moisture in it or
the sawdust, something is occurring during the fire to cause this. I
didn=92t have it happen in the summer firings in the trash can, so =
perhaps
it is firing in colder weather where the heat may cause condensation.
This is a problem that I want to solve as it happened to a couple of the
pots I fired and brought home from the Albion workshop. Since the wood
is in such close proximity to the pots, the moisture content could be
important. =20
When firing in a pit in the ground, then you have to consider the
moisture content of the ground, the humidity in the air, and possibly
the temperature in the air. My cohort, Ed Gray does not use salt so he
does not have the flaking problem. He fires most of his pots in a pit
fire.=20
Taylor, make sure your pots are dry after you wash them with FE OX and
Cu Carb before you put them in the fire if these findings are correct.
I have gotten an ecru color as well as yellows from copper but think
that the salmon color comes from the addition of the salt. I sure hate
to give the salt up, if I have to, as it does such neat things in the
fire. I would use only a minimal amount of salt and in the form of rock
salt. I have some gorgeous spotting on some shards. But I think that
the fire needs to be very roaring hot to overcome the corrosive action
of the salt. I would also add some iron in the sawdust mix to get
additional effects. I know that copper reds react much better if there
is a little iron available. Still, copper reds occur on porcelain as
well. Go figure!!!
Taylor wrote:
"Copper carb will give different colors depending. Greens when you
don't get good reduction and if you're nice to it maybe some red with
reduction. I've had great luck with miracle grow getting reds. Same pot
got greens from copper carb sprinkled on surface of pot. (didn't shovel
it in like you did). I still haven't been able to figure out what the
salt is doing in my pit, but it is supposed to give salmons as well as
other colors like yellow. I think I'll wash my pots with Fe OX and Cu
Carb this next pit. Keep up the pit firing 'cause there ain't much
better then a fire-filled hole in the ground."
Warm regards,
Bonnie Staffel
http://webpages.charter.net/bstaffel/
DVD=A0 Throwing with Coils and Slabs
DVD=A0 Beginning Processes
Charter Member Potters Council
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