In this Instructible i'll show you how to mix you own refractory. I want to give thanks to Lionel Oliver II at http://www.backyardmetalcasting.com! I take credit for making the Instructible, everything else goes to him! ENJOY!!
"Masonry cement" (on the left) is not the same as "Portland cement". Portland cement is plain cement powder and specifically says Portland cement.
Masonry cement is a mixture of Portland cement and sand. It may also contain other components (admixtures) to provide a certain characteristic such as waterproofing agents, colors etc. In some cases you only need to add water to masonry cement mixtures.
Fireclay is usually (at least where I buy it) sold in 50lbs (about 23kg) plain packages and they don't even say "fireclay" on them. I get it from a place that exclusively sells masonry supplies for $8.00 (2002 prices). I've never been to a ceramics supply place so I can't say whether or not they sell it. Whip out your phone book and call if your wondering, in fact maybe I'll do that.
Another type of clay is Bentonite clay. I haven't been able to find any where I'm at. I've read that it's available from feed stores and farm supply places. Kitty litter is bentonite clay. But unless you have a big rock tumbler or ball mill I don't expect anyone to use this source. Anyone willing to grind enough kitty litter by hand is a much more patient person them me. I've tried using it whole but it didn't work, however I think I might know a way.