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refiring oxidized pots

updated wed 29 oct 97

 

Tracy Wilson on sat 25 oct 97

Howdy folks...
Well I just tried an experiment and it didn't turn out very well.
I tried to make my 36 cu ft downdraft kiln into a 40 cu ft downdraft kiln
by lowering the bottom shelf into no-person's-land. This move was
partially to get some extra pots out of the firing but also to try to speed
up the firing time from 22 hrs. to anything quicker.
Unfortunately, this area (I just discovered) gets NO reduction what so
ever.
Has anyone ever had any luck refiring oxidized pots? It seems that the
claybody has already hardened when I come up through body reduction temps
the second time around.
I suppose the seconds room was getting a little low, but...
_____________________________
Tracy Wilson
Saltbox Pottery
#4 Shaw Rd.
Woolwich, ME 04579
phone: 207-443-5586
fax: 207-443-6544
email: saltbox@ime.net
web: http://www.ime.net/~dwilson/
_____________________________

Peggy Heer on sun 26 oct 97

Hi Tracy....I once got a teapot out of a reduction fire (gas kiln) which
was totally oxidized on one side and totally reduced on the other
side...split the fire results right down the middle of the TP from the top
of it to the bottom. I tried refiring the pot in what was a heavy
reduction fire and the oxidation side did not reduce. Fired it several
times just to make sure...this all happened just after I built my gas kiln
in '75. and was just learning how to fire, making ajustments to bag walls,
etc, etc.
Anyway the bottom line, in my experience, is no you cannot reduce after
oxidation....others may have a different experience. I still have that
teapot and have the reduction side on display to show me what I am missing
without my gas kiln. :>{{
Someday soon I will have it again.
As Always In Clay Peggy


>----------------------------Original message----------------------------
>Howdy folks...
> Well I just tried an experiment and it didn't turn out very well.
> I tried to make my 36 cu ft downdraft kiln into a 40 cu ft
>downdraft kiln
>by lowering the bottom shelf into no-person's-land. This move was
>partially to get some extra pots out of the firing but also to try to speed
>up the firing time from 22 hrs. to anything quicker.
> Unfortunately, this area (I just discovered) gets NO reduction what so
>ever.
> Has anyone ever had any luck refiring oxidized pots? It seems that the
>claybody has already hardened when I come up through body reduction temps
>the second time around.
> I suppose the seconds room was getting a little low, but...
>_____________________________
>Tracy Wilson
>Saltbox Pottery
>#4 Shaw Rd.
>Woolwich, ME 04579
>phone: 207-443-5586
>fax: 207-443-6544
>email: saltbox@ime.net
>web: http://www.ime.net/~dwilson/
>_____________________________

Peggy Heer / Heer Pottery E-Mail p4337@connect.ab.ca
52120 Range Road 223
Sherwood Park, AB. Canada T8C 1A7
Phone (403) 922-6270
http://www.ffa.ucalgary.ca/artists/pheer/

Eric Struck on tue 28 oct 97

Hi Tracy,
If your trying to get copper reds, fire your oxidized pots to ~ cone 018
then reduce heavily. I've tried it and it works. The process is explained
in detail in "Syllabus for Advanced Ceramics" by F. Carlton Ball, Keramos
Books.
Another interesting technique is transmutation lustre. Make a paste using
clay and copper carb, smear it on your pot, fire to cone 018, reduce
heavily. Carefull not to overfire or the paste will stick to the glaze.
When the kiln has cooled rub off the paste and presto, copper red. This is
assuming that you have a copper red base. I've tried this technique with a
low fire black glaze and got copper color
I've had better luck with the tansmutation lustre, you dont have to reduce
quite so hard. Anyway, good luck!
Eric Struck
ericstr@lightspeed.net