about reduction firing problem

[Hammer]

Hi, this is my first time to firing with a reduction way,

but it looks didn't so success, because the glaze color looks so uneven,

my temperature is set 1200°C and reduction time is start from 880°C and turn off on 1200°C,

I am really not sure my gas fire is too weak? or too long? make some area looks didn't like a celadon,

it become too dark and brown.

 

How should I make it better on next time?

 

Many Thanks 

PS: my kiln is electric and can inject the gas on the sideway.

 

[Bill Kielb]

Interesting, the glaze is very crazed  on that cup so not a great fit. Reduction only affects a few metals and level of reduction is a thing. So when you say a better look what look are you trying to achieve? Copper reds for instance are often shown as a product of reduction because the effect is dramatic. (See Below)

What look are you trying to achieve?

 

[Callie Beller Diesel]

I think your problem is not your firing, but maybe your glaze thickness. When I worked with high fire celadons, I found that if the glaze was a bit too thin, it would not develop the colour fully. It looks like you’re very close. You might find recording the glaze weight or specific gravity to be helpful.

Even the traditional Korean potters had results that looked a little like this. 

 

Welcome to the forum!

[Hammer]

Hi Bill and Callie, thank you try to solve my problem,

I think I want to make a color just like a little light green to blue glaze, not a dark brown green...

so maybe the reduction gas wasn't the main problem,

I think next time I can try to add the thickness of glaze layer.

 

Many Thanks,

Hammer

 

[Bill Kielb]

1 hour ago, Hammer said:

so maybe the reduction gas wasn't the main problem,

I think next time I can try to add the thickness of glaze layer.

 

Maybe, definitely something to try. Here is a general statement about iron in reduction.  In reduction 1‐6% w/calcium phosphate gives blues, ½ ‐3% with some calcium gives celadons. Only some metals are influenced, iron being one of them and I think your sample above shows reduction in one area with very little elsewhere. So concentration is a thing and uniformity as well as how long something is reduced for. All fun things to experiment with.