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Hi all,

I'm looking for advice on how to achieve a darker charcoal/black carbon trap finish. I'm working with Malcolm Davis Shino on bee mix & coleman porcelain. I have been unable to fire the gas reduction downdraft kiln because of work so I haven't been able to play around with it. This image was taken a while back before I really cared how heavy the carbon trap was (record record record). This is what I'm trying to achieve. It's Malcolm Davis Shino on Coleman Porcelain with wax resist fired to cone 10 in gas reduction. Any thoughts?

IMG_0013.jpg

Edited by Mullins Pottery

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wow- that is dark! I've never had Malcom Davis go that dark- did you start reducing at 012? I've had Penn State Shino go to a nice dark grey with black edges on the rims & even celadon with black on the rims when I started reducing early in the firing. 

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22 minutes ago, Mullins Pottery said:

What do you look for in terms of reduction when you say heavily? In other words how do you gauge how heavy/light the reduction is? What are the key indicators you look for when gauging reduction?

The size and color of flame coming out of the peep\chimney

Edited by liambesaw

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1 hour ago, Mullins Pottery said:

What do you look for in terms of reduction when you say heavily? In other words how do you gauge how heavy/light the reduction is? What are the key indicators you look for when gauging reduction?

For carbon trap, you have to reduce a lot heavier than a normal reduction. You need it to be smoking, lot of free carbon, if you want really black trapping.

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1 hour ago, Mullins Pottery said:

Also I know at my school they usually do a body reduction around 1400 for 30-40 min is too soon? 

That's pretty early. Reducing too early can cause issues with the clay body, and personally I find that any earlier than 012 makes it more difficult to get the kiln set properly.

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FWIW, I own a small Malcolm Davis teapot that is as black as OP’s photo. It was priced literally half as much as his other teapots of the same size. I’m guessing Mr. Davis did not intend it to look this way. But hey I think it’s beautiful. 

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agreed- 012 with flames licking out the edge of the door the whole time and that stall later on when she's almost done ( & you're tired & wanting to shut the kiln down & go to bed!)

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I've been fiddling with Malcolm's Shino for the past 3 seasons with varied results. I respect those who seem to have mastered the art of firing it with desired results.

It's a very organic and temperate glaze i how it reacts.

Here's a thread where I asked the question Proper Reduction Firing with varied response.

Meantime, just came across this : https://ceramicartsnetwork.org/daily/firing-techniques/gas-kiln-firing/demystifying-the-reduction-firing-process/

That said, not sure what you're trying to achieve with the piece you're showing. Most MS shino pieces go spotty qnd/or orange-ish if fired right.

The eresult you're showing could be attained using something other than shino, for instance a temoku or other high iron glaze...

 

Edited by Rex Johnson

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Thanks for the info. In terms of my goals with this process I know that there are other ways to accomplish a similar aesthetic with other glazes but I'm working with shino because  I enjoy the carbon trap process/color pallet . Also I've been tinkering with Gustin shino and Malcolm Davis shino to produce high fire overglaze decorations. At first separately but more recently I've been using them on the same pot. Shino's don't shift in the firing so they have been good candidates for brushwork and such. So basically getting that charcoal backdrop is just one part of the equation.  I very much enjoy the oranges & reds that are so common with malcolm davis i'm just trying to get a better handle on the carbon trapping part.

I fired a Geil downdraft over the weekend with some mixed results. I had most of my carbon trap pieces come out red-orange/orange with some carbon trapping .  Most of my bowls got that black carbon trapping that i'm looking for on the underside. One bottle that was glazed thicker than the rest ended up forest/snot green from too much carbon I assume I've never had this but I've seen it in the work of others. I'm wondering if I just glaze my pieces like normal and just reduce harder. With your combined experience does that sound like it might produce the desired results?

Firing schedule:

candled to 1250

opened up gas took it up to 1535 then began reduction

reduced to for 45 min, temp at end of reduction 1640

kept neutral atmosphere (slightly reduced) till end of firing (2310)

 

This is a link for a video of the pots from the firing. Sorry I haven't had time to photograph yet.

https://drive.google.com/open?id=0BwDDXHDlS0HGWnBhdy1JMmJfSUZESmM1Ul9zdDBEVGlEaGFz

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"opened up gas took it up to 1535 then began reduction

reduced to for 45 min, temp at end of reduction 1640

kept neutral atmosphere (slightly reduced) till end of firing (2310)"

So you reduced at 1535 for 45 minutes and then in neutral up to cone 10?

Those are fantastic results! I wish I could get my MS to react that well.

I've fired the same way but rarely get all that nice orange-ness.

Tell me more...

Edited by Rex Johnson

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