John Britt cita:
Dick Leach from Albion College in Michigan developed a number of castable mixtures that worked very well he had some that lasted for 20 years or so. A recipie that he used and called "excellent" was as follows:
C/10 firing range(salt too) castable
PARTS MATERIAL .
#2.5 crushed corn cobs
# 2.0 clay
# 2.5 grog
# 0.5 alumina
# 1.0 cement
# Mix to "snowball" consistency; ram it up. 4" thick walls.