Little Brown Jug + Dig Deeper Exhibition - The Arts Center of the Capital Region

 

     This past summer Bruce became aware of a really interesting upcoming exhibit called the Little Brown Jug Project taking place at The Arts Center of the Capital Region in Troy, New York. He decided to join in on the fun of developing a glaze from Schaghticoke Slip Clay, a close cousin to the historically famous Albany Slip Clay from the Hudson River Valley of NY.  After filling out the online forms and paying a nominal fee to cover shipping, the folks sponsoring the project mailed us enough of this raw slip material to do many tests and actually glaze a good number of pottery pieces to submit to jury for the show.

     For more in-depth information on this project you can visit the Little Brown Jug Project. Also visit Margaret Boozer's  website, one of the "Little Jug" organizers and Ceramic Artist from Northern Virginia, for additional information.

     In the 1970s Bruce began his clay career in his hometown of Stillwater, at the Oklahoma State University ceramics studio. During this period Albany slip was an important glaze ingredient, along with Colemanite, and Volcanic Ash sourced from a farmer’s field in Wilson, Kansas. Bruce’s first solo successful glaze development, labeled “4X” was 25% each of Albany Slip, Red Art Clay, Colemanite, and Volcanic Ash with Copper and Rutile as colorants fired to cone 6. Given the state of his understanding of glaze chemistry at that time, it is ample evidence of how successful these materials are as glaze ingredients. This is especially true of Albany Slip Clay, which can be a complete glaze by itself if fired to a high enough temperature, or the Albany Slip Clay can easily be fluxed with materials such as Colemanite or Frits to melt at lower temperatures. 

     “True” Albany Slip is no longer available commercially due to the closing of the mining in that area. In the late 1980s, the city of Albany, NY needed to grow and the real estate value outstripped the clay’s commercial value from the ceramics community. Many substitutes for Albany slip have appeared on the market--sold as Albany replacements-- the most well known today is Alberta Slip. As seen on Digital Fire, a blend of clays and minerals to approximately reproduce the chemistry of Albany Slip in a consistent fashion. Another promising product is Sheffield Pottery’s Albany slip substitute made from their Sheffield slip clay and amended to a very close chemistry with the original Albany slip.  

Bruce's Final Glaze Formula - Schaggy B

Schaghticoke slip       37%  

Calcined Alberta slip  31%

Ferro Frit 3269            11%  

Bisthmuth oxide         11%  

Veegum Cer                1.5%

CMC                            0.5%     

We used calcined Alberta because that is what we had on hand in our glaze lab. We had previously calcined some Alberta clay to just under 1900F in a bisque firing, and we accounted for the LOI of approximately 9% at that temperature with some fuzzy math. Without the calcined slip the glaze had too much shrinkage and consequent crawling if used on biscuit fired pieces. We added gums to our glaze to facilitate brushing the glaze on the pottery.  We apply the glaze this way, instead of dipping or pouring the glaze, in order to protect the details of the fossil fish and underglaze image decoration.

The piece is Schaggy-B on Starwork’s cone 6 Star Red Cay with underglaze decoration.

This bottle is Schaggy-B over sliptrailed fossil fish decoration on Standard cone 6 porcelain #365