Forge (Furnace) Liner

[mstu]

Kitty litter, the cheapest kind (bentonite, not fuller's earth), and certainly use the unscented kind. It should dissolve into mud when wet if it's the right kind. Mix in a bag of perlite or vermiculite (potting soil additives), then when it dries, fill in the cracks with more of the same. It should be less than $10 to fill a forge that size.

Michael

[blkbear]

The cat will be upset (hahahahaha!!!) when she sees that I am heading outside and not cleaning out her box with the new stuff.

Brian

[FredW]

I made some refractory for a small foundry using sillica sand, fireclay (Hawthorn bond), Mizzou, perlite, and sawdust.
The sawdust will burn out making the mix more insulating. Any kind of fireclay will work.
I let it set up for a month befor firing. I then fire it as if it were ready to go. I melted some brass and had no cracks when done.

Fred

[Wim]

I made a forge from an old barbeque too. No liner. The funnel shaped coal box is made from mildsteel is surrounded by an air box. I blow my air in that box, it come out the bottom preheated and it cools the funnel at the same time.