Rated to 2600 degrees F (1427 C) and is 8lb density (HiQuality) Ceramic Blanket Fiber (fiber) Insulation (for forges, kilns, tempering ovens; Inswool /aka Kaowool). Sold in pre-cut lengths or full box.
#1 Tip: Apply our Ceramic Refractory Paint (ITC -100) to your wool (and brick).
Our ITC-100 greatly increases heat reflection, liner durability, flux resistance, forge efficiency (by up to 40%), it prevents wool fiber from becoming aerosolized, and it is stable to 5000 degrees. A little goes a long way, and our pricing is remarkable. (Metaphorically: ITC 100 does to a propane forge what a turbocharger does to a diesel motor - it's like free power and efficiency.)
#2 Tip: Use wool rated @ 2600 degrees (no less!) in your Propane Forge.
Propane atmospheric forges have a theoretical combustion temperature limit under 2600 degrees. (Of course, this would go up if someone started cutting the propane with acetylene ...). This is important because wool heated above its rating becomes aerosolized, and is not healthy to breathe (think asbestos). Wool rated at 2400 degrees (or 2200, or 1800 ..) will look the same as our 2600 degree wool, is fractionally cheaper, but I strongly recommend against its use at welding heats.
#3 Tip: 1" wool with Rigidizer is our best-seller, but we also stock 1.5" & 2."
While most forges use a total thickness of 2" of wool, most people double up with TWO layers of the 1" blanket in order to make fitting within tight spaces and around curves easier, and it allows you the option of replacing only the exposed 1" (half thickness) of the blanket. You can apply our inexpensive spray-on Rigidizer to stiffen up the wool blanket. (Also - it is easier to apply ITC-100 Ceramic Refractory Paint onto rigidized wool).