Has anyone tried Sakrete high heat mortar for hearth and dome?
It is in stock at my local Lowe's for $ 58.00 for 50 lbs.

Features:
  • For applications up to 2550 F (1399 C)
  • Air entrained for freeze-thaw resistance
  • Underlayment or wear surface
  • One hour working time
  • Non water soluble
  • Great workability and high strength
After all the looking for fire clay for home brew mix, this could be a dream come true at just over half the price of heat stop and found just five miles away.

Jack