Flashing Clay Bodies

I am currently searching for a deep red/orange clay body that flashes this color in atmospheric firings to Cone 8 and above. I have mixed roughly 20 tests and made cups out of them and fired them in Soda and Wood/Salt kilns to Cone 8 and Cone 10 respectively. Here are my findings.

It seems that red/orange flashing is promoted by small amounts of iron chemically incorporated in high temperature clay and dry material ingredients introduced in the clay body.

What Parmelee suggests in his book Ceramic Glazes that clay bodies higher in silica will need higher percentages of iron compared to clay bodies higher in alumina, stays true. Though, iron percentages stay below 3% on a whole.

Also, it seems that the silica/alumina ratio should stay below 4. The current wood kiln has tests that are below 2 (showing a high alumina content)

My tests have 2 different realms. One direction is a grolleg/PV body and the other is a Neph Sy/silica body. Both directions are currently using high alumina materials.

These are the tests in a cone 8/9 Soda Firing
4
clay body test #4
5
Clay body test #5
6
Clay body test #6

These 3 tests were fired in a first firing on a clay slab to ensure they would not melt down with higher than normal percentages of flux I was a little worried. I believe the firing had too much reduction to promote the flashing and too much soda to allow flashing in some areas. Cup number 6 has engulfed in soda, so no visible flashing is seen except on the foot of the cup.

My belief is that too thick a layer of flux (could be wood ash, soda in this case or salt) will stop the development or cover teh development of flashing. Also, I think that an oxidation atmosphere during 700 degree to 900 degree Celcius is neccesary for red/orange flashing, though I’m unsure if this needs to happen in firing or cooling or both.

This cup is blah blah blay

These 2 tests have 35% Mica with different types of silica mesh in them. Notice the excess iron in the mica has colored them brown as if they were made from EPK or were a dark stoneware, even though they are mainly grolleg kaolin. The silica mesh made no difference in the color. They were fired in different parts of the kiln.

These two tests have lower flux, but more silica and less mica and the color is very light almost a pastel pink. I believe the iron should have been increased to counter the added silica. It seems that 4-5% iron material needs to be added to get a deeper color.

Pocahontas State Park guest Artist

hand built ceramic workshop out in the rain, but under a tent.

December 1 &2 I was the guest artist at Pocahontas State Park.  The current CCC Museum was once a craft building built for the community to make arts and crafts in 1939. A wood kiln was built as well on the grounds to support pottery making.

Pulling up the sides of an earthenware cup

Each day I threw pottery and did a hand built workshop where the students made pinch pots and worked on different techniques such as rolling coils, attaching slabs, creating textures and making handles for cups.

The rangers did clay workshops with children and built a fire near the kiln. The made smores in the afternoon and talked to people walking or hiking by.

The weather was overcast, but being in the woods and making pottery outside was very cool.

I enjoyed all the volunteers that helped out and the park rangers who participated in making the event a success.

Making pinch pots and working on hand built techniques.

Teaching the volunteers how the wood kiln works, so they can pass it along to those that are interested.

Maybe, next time the weather will be nicer and there will be more people. Either way I would love to work there again. What a great time.

Throwing Pottery on Treadle Wheel

Back in the ’90’s I worked in Woody Creek, Colorado at the Aspen Community School. I did after school programs in organic gardening, resource efficient construction and pottery.

While I was there I used a treadle wheel to make pottery which is not electric. You kick it and make the wheel head spin.

It is a great way to connect with the rhythm of making pottery. I loved doing it, but no longer have access to a treadle wheel and they are expensive to purchase. I think they go for $3000 nowadays.

 

Wood Fired Pots

Bourbon/Sake/Tea Cup

Yes, the annual firing was done the week after Thanksgiving and I went and picked up my pottery last night.

I am so thankful for Mike and Alex firing my pots at Tree Hill Pottery, here in Richmond, VA. My work turned out great and I’m excited to show you the results.

I reformulated my clay body to create a red flashing clay body. Unfortunately, I failed again. I researched and studied flashing bodies in Graduate School and lost the recipes I created, so now I’m working to create a new body with less expensive and readily available ingredients.

Bourbon/Sake/Tea Cup

Bourbon/Sake/Tea Cup

I have 4 glazes that are really looking good in the firing. My favorites are the Tenmoku, Amber, Cobolt and Pumice. I have a great Oribe, but didn’t use it in this firing. My next glaze will be a white.

Bourbon/Sake/Tea Cup

I hope you like these as much as I do. They are an Asian aesthetic. The cups are small holding 5-6oz. The trays are 14-16in long.

🙂 Matt