what to line the arch with

[michael marrs]

have seen posts saying their arch is lined w/ fire brick, fire board , blankets of different types? My arch is block, and I assume will crack so I also assume these materials aid in not the longevity of the blocks. yes,no?

[Ghs57]

I used ceramic insulation board (arch board) in my evap behind the fire brick. It keeps most of the heat inside, but I'm not as crazy about it as I could be. Any exposed areas seem to get flaky, and the mortar also pulls away from the board, in some cases leaving the bricks lose. It seems the fire brick alone will preserve the block, as in my fireplace. There is no insulation behind the fire brick there, but it doesn't typically burn as hot as the evaporator. If you use insulation, you really need to protect it from impact (with your fuel when loading the arch) with fire brick.

[dadtkm]

my arch is metal , the insulation helps keep the heat in. A few spots are uninsulated and they are quite a bit hotter. Sorta makes sense, insulated block would be cooler and cooler block would last longer. Maybe ?