arch insulation

[nhdog]

Keeping the heat in the arch is important and various means have been discussed using brick or fire board etc. Space permitting, would not sand held in a form built around the outside of a barrel or oil tank arch work as well, providing of course it didn't interfere with the operation? With some of the smaller barrel arches, this would allow more room for the fire box.

[madmapler]

I stacked blocks around a sheetmetal arch that I built as my first evaporator. It worked well but the sheetmetal wouldn't hold up for many seasons. It gets red hot in there. Sand may dissipate some of the heat better. I don't know. The idea is to insulate between the fire and the sheetmetal.

[ScottyWelden]

First year, I cut up an aluminum truck box and surrounded it with insulation and then blocks. at season' s end. the aluminum was 90% gone.
Second year, I found an old, heavy-gauge file cabinet, and did the same. At season's end, 15% of the metal was gone.
Next year, it's gonna be fire brick for the box. (Still not sure whether to keep the insulation layer, though)

[Bricklayer]

This was the first year with my new home built arch and i used 1.5" Roxul IS board in the firebox with firebrick to cover it. Worked amazing. I could hold my hand on the metal sides for about 10 seconds when arch was at running temp. Is about 50$ for a bag of it. A fraction of the cost of ceramic blanket. Can't take direct flame though or it will dry out and fall apart like arch board