Perlite Refractory Concrete

[Helicopter Seeds]

Hello,
Anybody use home-made refractory concrete with Perlite or vermiculite?

Looking for an inexpensive way to add refractory lining to my brick arch to get more heat into the pans where it counts. I still hesitate to do more permanent work as I would like to add a better pan down the road and don't want to permanently consume my regular bricks. Fire bricks would cost over a hundred bucks, but pretty basic and easy. Saw some videos and it using sodium silicate "water glass" as a surfacer binder you can have a good clean surface. Seems easy enough and I thought to stretch metal plastering mesh on angle iron (used, I have some) and build up an inch thick. one bag would be enough at around 17 dollars, probably be done for under 50 with a removable refractory wall. This way, if I do get a bigger evaporator pan, my arch can still be modified without busting mortar.

Any thoughts?

[Bricklayer]

It's worth a try, I've made vermiculite concrete many times for insulating around flu tile in fireplaces but never seen it exposed to flame. It's very porous when it cures. If you poured a 2" slab you could probley see right through it. I've added sand to the mix before also to thicken it up. Not sure how this would affect the fire rating to open flame. You will have to make sure it's super dry when you fire up the arch to try it. If not all the moisture and air pockets will start popping like popcorn.