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Mizzou insulation ability question

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Hello everyone, a total newbie to forging, blacksmithing, etc. but getting ready to build my first forge.  So I saw all the video's on u-tube using the perlite and sodium silicate, saw some more video's where they were adding mortar mix, etc.  So I did even more reading in the comments section of said video's and found out that perlite and sodium silicate aren't good refractorants, above 1900* and just as well throw the mortar mix away.  The I started doing a little more research on several different forums and having no luck finding refractory cement locally, I did find Mizzou on Amazon.

What I'm wondering is if straight Mizzou is a good enough insulator that I could use it for the first inch or two of the inner chamber, then finish with a Mizzou and perlite mixture on the outer layer next to the tank wall.  Will the straight Mizzou insulate the perlite well enough to keep it from burning up?  If it does burn up is it a problem?

I'm planning on a 30# propane tank with a "D" opening where the carry handle was located.

It's $75 for a 55# bag of Mizzou, would it be cheaper to go with a ceramic blanket material and that process?

Thanks in advance,


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Welcome aboard Ken, glad to have you. Mizzou is a tough as can be reasonably flux resistant refractory but no more insulation than limestone.

If you check out the gas forge section on Iforge you can find the answers to your questions except where to find it locally. The current thread is Forges 101 and discusses the most recent popularly thought of as best forge liners. 

One charming little custom you'll discover here is a rather vigorous response to Youtube How to videos and especially all the idiot home brew refractories that have become urban legend and won't go away. At least you didn't fall into the Plaster of Paris and sand idiocy, thats not only bad it'd dangerous. 

Perlite CAN be used as a backer providing more insulation to higher end refractories. I recommend you NOT try turning Mizzou into an insulating refractory with Perlite, especially when there are already very good insulating refractories available, even in small quantities.

Just don't get in a hurry, all rushing tends to do is make mistakes permanent more quickly.

Again, good to have you.

Frosty The Lucky.

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Frosty is right. Much of what you see and read of Youtube is what I call "happy talk", but urban legends is a dead on description. You can find good ideas on YouTube, but in trying to winnow them from all the outright horrifying advice, you would need to already know all the right answers. Its kind of a question of the blind leading the blind :P

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Having just finished building my first forge, and going through the same questions, all I can say is check with Wayne Coe for all your insulation needs for your forge! He is on this site and has his own pages also I was totally happy with the quality of material and shipping time. Price was very reasonable also!

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