David Zdrazil

Examining some wild clay

An active landslide of clay, along the coast of Northern California. 

A cracked texture seen through a green-blue glaze.

Clay on the coast of northern California. 

Gathering some clay near the coast in Northern California.

Detail of a wooden lid made from old growth Redwood burl. 

The toasty surface of a vessel after being wood fired.  The colors and patterns of the unglazed piece are a result of the flamepath produced by the proximity of other objects.  Straw soaked in salt water was placed on the piece for a hidasuki effect.    

Wood fired stoneware, native WI clay, natural ash glaze

The atmosphere of a wood kiln produced a natural glaze which draws out minerals and impurities from a native Wisconsin clay.  Crystals grow during the cooling process.

Pattern from wadding on the bottom of a wood fired vessel.  Every piece in the wood kiln is placed on small wads of clay to prevent the wares from being fused to each other or kiln shelves during the firing.    

Seashells can be used in the wood kiln to separate wares or prevent them from fusing to kiln shelves as wood ash accumulates and melts into a natural glaze.  The shells leave marks pieces but break down into powder after the firing. 

A wooden lid made from Buckeye burl.

A dark glaze made from 100% local materials.  Similar to temmoku glazes, a tea dust effect happens in the wood kiln under the right conditions.   

A closer look a wood fired piece

A very specific process is required to achieve this luscious blue glaze in a wood kiln. 

Crystallization in the glaze around the rim.

Construction of my 2 chamber wood kiln.

This versatile and unique little wood fired kiln is my own original design.  It is inspired by a combination of anagama, ground hog and updraft bottle kiln designs.  The kiln is very efficient and can be fired with very little smoke.  It is usually fired for approximately 20 to 30 hours.  

There are two wood fired chambers- soda is introduced to the back chamber of the kiln, which can be fired on its own. This kiln is located at College of the Redwoods in Eureka CA, it was designed and built by Zdrazil and students there. Several hundred pieces can be fired in each load.  

The wood firing atmosphere can have a great effect on the surfaces of the work inside the kiln.  Glazes and clay bodies develop rich variation while fly ash can accumulate and melt into a glassy glaze.  

This little kiln was built in 2014 on the island of Molokai, HI.  Sustainability and community are important parts of there, so
wood firing is a natural fit.

The first wood kiln I built near New Richmond, Wisconsin in 2001. 

The first wood kiln built at College of the Redwoods in 2008. It was destroyed during a 6.5 earthquake in 2010.

Peaking into the kiln at around 2000 degrees Fahrenheit.

Making firebricks. 2007.

This kiln and custom burner was built in 2009 to research firing with hydrogen because of it's potential as a sustainable fuel.
For more information see"Firing With Hydrogen" in Ceramics Technical #33

Kiln building class at College of the Redwoods. 2010. 

Cone 9 is down

A view into the back chamber.

A view into the front chamber.  The wood firing process can be equally important as the process of making the work.