A low fire red clay with approximately 10% fine mesh silica sand and approximately 5% fine mesh grog that fires to a light red-orange color at cone 06 to 05, and a richer, deeper red color when fired hotter, up to about a cone 2. During the summer of 2020, we completed a comprehensive test of our clay bodies. For each clay body, we tested 6 flat bars, which were rolled out on a slabroller. We ALSO tested vertical shrinkage of a thrown cylinder (6 sections, each with their own test) beginning weights in grams were recorded the lines and weights were measured & recorded when bone dry The samples were fired to Cone 04 lines and weights were measured & recorded again The flat tiles were then soaked in hot water for 1 1/2 hours, then weighed again Math magic was then done to calculate the average shrinkage wet-dry and average shrinkage overall for both flat and thrown tests, and the average water absorption was calculated based on the flat bars. We also figured the "LOI" (Loss on Ignition) by computing the fired weight against the bone dry weight. This tells us what percent of organics burn off in the firing. Flint Hills clays have been evaluated by a nationally certified toxicologist, and have been found to be in compliance with ASTM C-1023 and D-4236, and to not contain any material in sufficient quantity to be toxic or to constitute a chronic health hazard when used responsibly. RECOMMENDED VIDEO: Red Clay Comparison by Bracker's
