Hi all, just got in my Mizzou castable refractory, and am waiting on my ITC100. I have a couple questions on applying the stuff since ive  read so many different ways to do it. What im working with is a 12 dia × 18 long forge that im going to wrap with 2 layers of 2 in kaowool, bringing my interior down to roughly 4" diameter. Heres my ?

I have 20lbs how much do I need to mix up?

Should i let it dry a day or two before pouring the floor? 

I've been told mix it to yogart consistentcy and paste it in the forge,  good idea? 

Should I fire the Mizzou before applying ITC? 

Also I've had some issues with my old lining falling down after getting really hot! How do I avoid this with the expensive stuff!

4" of Kaowool is a little much and you'll find it stays put better if you use 1" and more wraps.

I've never used Mizzou but I'm not clear on what you want to do with it. Are you making a hard inner liner or just using it to coat the Kaowool? Those are two very different things.

If you're just washing the Kaowool you'll be ahead to use a proper kiln wash. Thin coats of Mizzou will heat check and spall.

If you're making a hard inner liner I had really good luck by casting between sonotubes, round concrete forms. I used sonotubes that nested with a 3/4" gap and rammed the refractory between them. The next day I just pealed the outer tube off and a day after that burned the inner one out.

I wrapped it with 2 layers of 1" 8lb. Kaowool and had to bind it tight with news paper (like a ring compressor) to get it in the forge shell. I just let the paper stay in place it wasn't bothering anything. I already drilled the hole for the burner so it was only a matter of sacrificing a garage sale hole saw to drill through the hard liner while it was still green.

I gave it a couple days with a light bulb in it to dry and lit my first fire for about 10 minutes, let it cool and it was ready to work.

This was before I knew about ITC-100 but the refractory was Pyramid Super, air set. It's a 4,000f (working and 4,700f peak) high phosphate plastic (rammable) refractory so is immune to flux damage and way exceeds the max temp an air propane burner can produce so it didn't need a wash.

It's about 25 years old by now and there's no sags, no flux holes or other damage worth mentioning. I just don't use it much anymore.

Frosty The Lucky.

am i seeing bubbling on your gas lines?  usually indicates leaks