Metal Casting Zone

My new kiln can supposedly hit 1500 deg F, but it has no temp controls and I have no pyrometer. So in my usual effort to do it well, but do it on the cheap, I'm looking into Orton pyrometric cones, as used by potters.

I guess they slump at specific temps so you know when you hit the mark. At 1200 deg F, I could shut off my kiln. Lost wax burnout complete, and not too hot.

According to this chart (www.bigceramicstore.com/Information/ConeChart.html), I need #020 cones, which would indicate 1180 deg F. Anyone ever used these? Does that sound like it makes sense?

By the way, a 50 pack of these cones costs $8, which is perfectly affordable, and I also just love the low-tech-ness of it all.

Anybody tried this?

I have a friend who uses this method....he uses three cones, one about 1100, one about 1200 and a third about 1300 or 1400.

He shuts off the kiln when the first cone is completely slumped over, the second just starting to sag and the third still intact.

Probably this is more accuracte thatn necessary, though.

I have also just read in a little how-to book on jewelry casting that you can use an aluminum nail instead of a cone....aluminum melts at about 1200 degrees.

I must have read that same book last night! Not sure where one finds aluminum nails, or what good those would do in the construction world... but aluminum rod is easy enough to find.

Aluminum nails are very common....used as roofing nails and nails for aluminum siding and evestroughs.
The book is "Handbook of Lost Wax and Investment Casting" by James E. Sopcak, cost $2.00 in 1968.
(edit)
I just Googled the book...it's listed on Amazon for about $20. but it also lokks like you can find it as a download.....