search  current discussion  categories  kilns & firing - misc 

oxidation after recuction ???

updated tue 28 oct 08

 

Gene Arnold on tue 21 oct 08


I down loaded the firing chart from the Axner web site to use as a guide =
with my oxi probe. All looks good in the firing schedule as a good =
reduction firing guide, but it calls for a 15 minute oxidation at cone =
10 then close the kiln up for cooling.

What I'm trying to figure out is why would you need to do oxidation at =
the end after reducing from cone 012 to cone 10??

Still trying to figure this gas kiln out, but getting closer every =
firing.

Gene=20
mudduck@mudduckpottery.net
www.mudduckpottery.net

Ron Roy on mon 27 oct 08


Hi Gene,

It's supposed to make sure the clay surface gets reoxidized - it that does
not happen the clay stays grey - not brown for instance.

That said - I don't know of any kiln that is tight enough to keep oxygen
out during cooling.

When you break a reduced pot - made with clay with iron in it - the inside
should be grey to black (the same colour all the way through) - and a thin
skin of brown reoxidized clay on the surface where there is no glaze.

RR


>I down loaded the firing chart from the Axner web site to use as a guide
>with my oxi probe. All looks good in the firing schedule as a good
>reduction firing guide, but it calls for a 15 minute oxidation at cone 10
>then close the kiln up for cooling.
>
>What I'm trying to figure out is why would you need to do oxidation at the
>end after reducing from cone 012 to cone 10??
>
>Still trying to figure this gas kiln out, but getting closer every firing.
>
>Gene
>mudduck@mudduckpottery.net
>www.mudduckpottery.net

Ron Roy
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0

Edouard Bastarache on mon 27 oct 08


Ron,

I only now ½-reduced for 20 minutes after a 20 minute full reduction
and "no problemo", my clay is dark brown enough.

I have a friend who full reduces for 20 minutes, does not oxidize,
he says there is enough cracks in the kiln walls that it will oxidize by
itelf during the night. His clay is dark brown and he says his glazes
look better now


Gis la revido (A la revoyure)

Edouard Bastarache
Spertesperantisto

Sorel-Tracy
Quebec
Canada

http://www.pshcanada.com/Toxicology.htm
http://www.flickr.com/photos/30058682@N00/
http://pagesperso-orange.fr/smart2000/livres.htm
http://www.flickr.com/photos/potier/20321056/
http://myblogsmesblogs.blogspot.com/
----- Original Message -----
From: "Ron Roy"
To:
Sent: Monday, October 27, 2008 6:27 PM
Subject: Re: oxidation after recuction ???


> Hi Gene,
>
> It's supposed to make sure the clay surface gets reoxidized - it that does
> not happen the clay stays grey - not brown for instance.
>
> That said - I don't know of any kiln that is tight enough to keep oxygen
> out during cooling.
>
> When you break a reduced pot - made with clay with iron in it - the inside
> should be grey to black (the same colour all the way through) - and a thin
> skin of brown reoxidized clay on the surface where there is no glaze.
>
> RR
>
>
>>I down loaded the firing chart from the Axner web site to use as a guide
>>with my oxi probe. All looks good in the firing schedule as a good
>>reduction firing guide, but it calls for a 15 minute oxidation at cone 10
>>then close the kiln up for cooling.
>>
>>What I'm trying to figure out is why would you need to do oxidation at the
>>end after reducing from cone 012 to cone 10??
>>
>>Still trying to figure this gas kiln out, but getting closer every firing.
>>
>>Gene
>>mudduck@mudduckpottery.net
>>www.mudduckpottery.net
>
> Ron Roy
> 15084 Little Lake Road
> Brighton, Ontario
> Canada
> K0K 1H0
>


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - http://www.avg.com
Version: 8.0.175 / Virus Database: 270.8.4/1749 - Release Date: 2008-10-27
07:57