Need advice on refractory for new foundry build

[Jay.bro]

I've been researching the web and all of the forums and I've had a small hiccup with my first foundry build. I built a box of dirt foundry and ended up burning through the bottom of it and caught it on fire a little bit. I plan on modifying it but I picked up a 20 lbs propane tank today that has a valve issue and I got to thinking. Does anyone have experience with pouring plaster of Paris and play sand mix over kaowool for use in a charcoal foundry I'm only going to be melting mostly aluminum, brass, copper and possibly try my hand at making some bronze or aluminum bronze in the future once I get more practiced. I'm just beginning my journey into metal casting but I've done a ton of research and I've read a few things about casting refractory over kaowool but not plaster/sand mix. I know its better to buy a tested refractory I was just looking at alternative options. Any advice would be appreciated and thank you in advance.

[Steve Sells]

STOP 

plaster of paris may be fine for lead and tin, but not anything like bronze or copper read more before building

[Jay.bro]

Okay thank you Steve that's what I was wanting to know I seen several youtubers that claim plaster would work and several ppl say they use it on other forum sites I think I'll find some refractory to pour over the kaowool instead

[Irondragon Forge ClayWorks]

Just a thought, most of the how to do it You Tube videos are down right dangerous, by folks who have no idea how to safely do what we do.

[Jay.bro]

Yeah I figured as much irondragon that's why I turned to the most experienced group of ppl I knew to ask