A low fire red clay 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, Kansas Clay completed a comprehensive test of their clay bodies. For each clay body, they tested 6 flat bars, which were rolled out on a slabroller. They ALSO tested vertical shrinkage of a thrown cylinder (6 sections, each with their own test). Flat Vertical Wet to Dry Shrinkage 6.06% 6.33% Overall Shrinkage 8.84% 9.17% Absorption 5.96% LOI 8.05% Testing Methodology Beginning weights in grams were recorded 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. *Important information about flat rate clay shipping Krueger Pottery Supply is doing our best to make sure you can get clay during this period of social distancing so we are now offering flat rate shipping via the US Postal Service on moist clays! You can choose a 25lb box shipped in a medium flat rate box or a 50lb box shipped in a large flat rate box. The shopping cart will correctly calculate the shipping for theses clays. Just make sure you select "Free Shipping" as your shipping method when you checkout. If you have any other items in your cart you will only be charged shipping for those items and not the clay. Important note. US Postal service flat rate price is only valid for orders shipped domestically. If you are buying clay to pick up, ship via UPS Ground, LTL Freight or delivery by KPS do not select "US Postal Service Clay Shipping" as it will add a shipping charge and increase your clay price. Bulk discounts on clay will only appear when you select the "50 Pound Box" size.
