More ^10 Reduction

Some Porcelain Shino bowls. Penn State inside, Malcolm's Shino outside.

Rutile Blue with Copper Grape over the Rutile inside

Some High Fire Bowls

Here's a few bowls from the last kiln load. The shino bowls have really old (Mixed 12/26/10) Malcolm Davis that I put on really thick on the outside and Penn State on the inside. The others are Tenmoku with Nuka over on the outside.

Re-firing Shino

I had some blistering on a couple of my saggar Shino pots so I decided to re-fire them to Cone 06 in oxidation using a low fire glaze to cover the blisters.
The pots in the center are the re-fired pots and those on the outside are pots that were fired at the same time, but not re-fired.

As you can see, the iron really got activated in the oxidation re-firing, but the pots didn't lose all the carbon trapping.

The amber colored glaze at the bottom of the mug and on the back of the cup is the low fire (commercial) glaze intended to fill in the craters left after I ground off the blisters. Next time I'll grind a little better...

One more saggar Shino

Malcolm Davis Shino saggar fired to Cone 6 1/2 in an electric kiln. I put two pieces of charcoal cut in half and about 1/3 cup of wood chips in the saggar this time. The glaze was brushed on the outside and the liner is MC6G Raw Sienna. I spattered some wax on the outside of the pot this time. I definitely need more experimentation with this as I'd like to get a result in between the last firing and this one.

Another Saggar Shino test

Malcolm Davis Shino saggar fired to Cone 8 in an electric kiln. I only put one piece of charcoal and about 1/3 cup of wood chips per saggar this time. The glaze was brushed on the outside of these pots. I poured Penn State Shino inside.

The only carbon trapping on the left cup was on the handle, which was right above the lump of charcoal. I guess I need to make sure to spread the charcoal out and I should probably use one and a half or two lumps in that saggar next time.

The other side of the cup on the right has almost no color (it all looks like the far right of the cup in the image above). The saggar it was in is a bit larger that the sagger used for the cup on the left and the charcoal and almost all of the wood chips were on the side that got color. I'll definitely put two lumps of charcoal in that one next time and make sure to spread the wood chips around better. It's kind of amazing to me that the atmosphere in a small sealed saggar would be so strongly affected by where the combustibles were located.

By the way, I was able to save the fiber blankets from both saggars this time by peeling them off the tops of the saggars very slowly and carefully.

Electric Saggar Reduction

I made a couple of saggars for testing reduction in my electric kiln. I sprayed Malcolm Davis Shino with Redart on the outside, Coleman Tea Dust liner. (Note to self - the shino had been sitting around for a couple months)

The saggars are cylinders about 8"x8". Inside each saggars, I put about 1/4 to 1/3 cup of wood chips, three charcoal briquettes, and a pot which was raised about 5/8" from the floor of the saggar on a clay "cookie" and triangle stilts. I put a layer of SuperWool 607 HT on top of the saggar (to plug any gaps) and covered that with a kiln shelf.

These got serious reduction. The Coleman Tea Dust is basically black inside except where the pyroxene crystals formed. The other side of the pot on the right is pretty much completely black. I'll definitely try with less combustible material next time. I also need to mix up enough Shino so I can dip the pots.

One other note. The fiber blanket stuck to the top of the saggar so it was ruined. The fiber costs $1.67 per square foot if you get it from eBay so it's not a ridiculous expense, but I'll probably try a strip around the top of the saggar next time to limit the amount of waste.


Before firing...

Fun with SiC

Artificial reduction in an electric kiln using silicon carbide. I got some 1500 grit Silicon Carbide from eBay to see if artificial reduction would work with SCM. These were fired to Cone 8 electric.

Here are the pots with Strontium Crystal Magic plus 1% Silicon Carbide as the base with Hanna's Fake Ash and Water Color Green + 1% Cobalt Oxide over.

These worked out really well. They look very similar to the pots fired in reduction. I'll probably do a comparison post with Oxidation, Reduction, and Artificial Reduction pots side by side at some point. The pot on the right is made of a really dark stoneware, which I assume caused the Water Color Green to change to the brownish green (kind of icky) color.

On the other hand, here are some pots with Malcolm Davis Shino (with Redart) plus 1% Silicon Carbide. The little pot had Coleman Tea Dust + 1% Silicon Carbide inside. Both of these glazes were bad ideas. The Shino is a huge mass of blisters that crumble into glass powder very easily. The Tea Dust was a pretty good crater glaze, but definitely not functional.

Before firing...

Left for Reduction Firing 8/23

We have two weeks off, so I probably won't see the results for three weeks. Crappy cel phone pics follow the jump...

Some More Shino 8/15

These all use the same glazes on the outside as the last set of Shino pots, but with Penn State Shino sprayed a little farther down the sides. Malcolm's Shino with Redart is on the bottoms. The bigger pots have Coleman Tea Dust inside, the bottom three have Black (Tenmoku) inside.

Here are three 1 1/2 pounders (15-17 oz).

and here are three 1 pounders (12-14 oz)

Some Shino cups ready for reduction firing

These have Penn State Shino on the top half, Malcolm's Shino on the bottom half, and Coleman Tea Dust inside.

There are also four smaller cups with the same glaze outside, but Black (Tenmoku) inside.

Reduction Firing July 25, 2010

Cone 10 reduction.
Pitcher - stoneware (Laguna Half and Half).

Sprayed Shino glazes. Penn State Shino near the top. Malcom Davis Shino (with Redart) lower. There's a line of a Tenmoku around the rim. Inside is VC AA Taffy - probably should have used the Tenmoku at least on the rim and beak.

Reduction Firing July 25, 2010

Cone 10 reduction. Stoneware shot glass (3 oz).

Sprayed ball-milled Malcolm Davis Shino (with Redart) pretty thin on the outside. Penn State Shino on the inside.

Reduction Firing July 25, 2010

More Shino glaze tests.
Cone 10 reduction. Did some stoneware bowls, here's two.
Top is Penn State Shino outside. Bottom is Malcolm Davis Shino (with Redart) outside. Both are sprayed fairly thin. Both bowls have VC AA Taffy poured inside with a brushed line of green Wood Ash just under the rim.

More Shino

Some Shino glaze experiments.

All pots have Penn State at the top and Malcolm Davis below (with overlap). All are sprayed on fairly thin.

One interesting note is that both shino glazes were mixed up over a month before this use. I've heard it's hard to get color from Malcolm Davis shino if it's more that a week or so old, but I definitely didn't have any lack of color. I let the Penn State shino overlap the Tenmoku liner and that didn't work out very well this time (blistered, which hasn't been a problem in the past).

More Shino

Some Shino glaze experiments.

Left and right are Penn State Shino. Center is Penn State at the top and Malcolm Davis below. All are sprayed on fairly thin. (The bowl is one of the bad bowls from the previous post.)

Old Stuff - Shino

Malcolm Davis Shino glaze sprayed on.
Cone 9.5 Reduction.

Old Stuff - Shino

Some Malcolm Davis Shino glaze sprayed on...

Cone 9.5 Reduction
Not much carbon trap on this one.