eastmeetswest – Hardwick Handmade pottery

These pots were fired in a 2 chamber woodkiln by Tree Hill Pottery. They fire with revitalized wood scraps and logs found in the Richmond, VA area. The kiln fires from cone 6 to cone 11 in oxidation and reduction depending on the area of the kiln. The following work represents my glaze tests in different locations of the wood/salt chamber of the kiln.

Magnesia glaze on the inside with 3% iron as a colorant. This cup was once fired in a wood/salt atmosphere to cone 10. Cup was hand built over a wood hump mold with texture added to the outside by pressing and paddling with hand made and found wooden sticks.

*Bourbon, Sake, Tea Cup 4″ x3″x 4″ $45.00*
*Email hardwickhandmade@gmail.com for orders*

Wood/Salt fired cup with woodash celadon glaze in the Chinese Longuan celadon tradition.

Trans Clear Pumice Glaze that can be found on Glazy.org This glaze is high in Calcium Carbonate and goes clear green where thick in reduction atmospheres over 1260 degrees cooled quickly. In an oxidized atmosphere this glaze goes clear/yellow. This cup is clear/yellow on the inside and clear/green on the outside indicating 2 different atmospheres at different times in teh firing.

VC Matte base. This cup has crystals from dark brown to green. The clay body looks reduced, but the interior of the cup looks oxidized and is a buttery yellow. My guess is the outside is showing carbon trapping from early in the firing producing the dark brown color. The green color may be coming from the salt in the kiln, but more tests are necessary.

Fake Ash glaze is darker and more brown on the exterior. Interior is showing more rivulets with more yellow coloration. Glaze has over 40% calcium carbonate, but has not run much. So, very possible the temp was not at cone 10. Surface is dry, but mature.

This is one of many tests for a blue celadon. It is showing a blue/green cast, but glaze needs to be much thicker. Glaze analysis was pulled from Nigel Wood’s book Chinese Glazes. Next firing will be same unaltered glaze with thicker application. Slight crystallization is evident.

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

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.

Tag: eastmeetswest

New Ceramics from the Varina Woodkiln

Flashing Clay Bodies