[Clayart] alternative to hay in primitive kilns

[Snail Scott]

Carolyn: In my plaster molds (for wax casting, not clay slip)  I have used horsehair, bulk hemp fiber, and excelsior to give tensile strength. They are going to be less cost-effective than straw for larger structures, but likely will work in your castable refractory in a similar way. Horsehair is very resistant to rot, and hemp is surprisingly strong. Excelsior (springy shredded wood fiber) is sold for loose packing material, and also as pads for swamp coolers. I believe it was also formerly used as taxidermy stuffing!)

-Snail