help with cooking in hole (pit firing)

[ondina]

good morning
I write why I need help about Pit Firing

I don't understand why the result of my ceramic on pit firing is so gray, dirty, ...

I do:
I put iron mesh on the piece, I wrap it with cloth and leave it submerged on copper sulfate for 4 or more days
then I let it dry and I cook it in a metal drum
I put wood and sawdust
and I am 4 hours burning, then I cover (but letting it breathe, so as not carbonization)

But when the ceramic is cold and I clean them, they always have dirty and gray colors
It never get pretty red
or white and strong black contrasts
Can somebody help me? I do not understand why..
I've seen a lot of videos and I've read a lot
and I get very ugly results

thanks!

 

 

Ondina

[liambesaw]

The copper red is from a lack of oxygen, meaning when you cover it, you should not let it breathe.

[Bill Kielb]

You are trying for surface reduction so look at Raku glazes for composition because copper alone is difficult to get an effect without tin. Then read a bit about reduction. A common thread here is to create carbon monoxide, letting oxygen in too early creates that ugly green / grey.

[ondina]

On 4/23/2021 at 1:00 AM, liambesaw said:

The copper red is from a lack of oxygen, meaning when you cover it, you should not let it breathe.

thank you !!

thanks for the tips!
i tried it and it worked

[ondina]

On 4/23/2021 at 1:59 AM, Bill Kielb said:

You are trying for surface reduction so look at Raku glazes for composition because copper alone is difficult to get an effect without tin. Then read a bit about reduction. A common thread here is to create carbon monoxide, letting oxygen in too early creates that ugly green / grey.

Thank you!! thanks for the tips!
(: