Refractory? Or not Refractory............
The army has relented for a couple of days, and granted us a mmmm......weekdayend? Anyways, I took a break from working on my engine, and played with concrete all weeke........I mean monday and tuesday. Including the furnace for my foundry. I started small. Merely poured a new mailbox post (2.5 parts sand, 2.5 parts gravel from the shitty grading job the did in front of my house, take that Copperas Cove!!!!, 1 part portland cement, and just a leeetle bit of water.)
That was fun, so I finished my furnace (for metalcasting, see mmm...two? articles down). I finally got bentonite clay for a fire clay to use to make refractory (heat reflecting concrete for a lining). (1.5 parts portland cement, 2 parts silica sand, 1.5 parts perlite (they sell it in the fertilizer section at the hardware store), and 2 parts fire clay/bentonite. (Also, most clumping cat litters are pure bentonite, but unless you have a mortar and pestle and your REEAALY patient, you can get some from a feed store, where they sell it as a pond lining.)
Granted, that all sounds as fun as regrouting tile, but I got to spend my "weekend" being manly, and literally up to my elbows in gooey concrete. Pictures of the furnace will follow in a day or two, but it's frikin dark out now. Maybe when I give it it's first firing this weekend. P.S. This will NOT be as cool looking as the liquid oxygen bbq.Link
But then again, he can't pour metal with his............unless you count a lap full of molten bbq grill.