Metal Casting Zone

Hi there, I'm a new guy here, glad to find some like-minded folks.

I have a burnout oven made from a hotplate with an insulated box on top (see pic). It maybe reaches 500˚F - clearly not enough to actually "burnout" much of anything. I guess it's more of a "meltout" oven. My silver and gold castings, however have been OK, but I could stand fewer failed castings... none would be nice.

For other projects, I have a little home-made charcoal "garbage can" furnace that melts aluminum and brass, so I know it gets plenty hot. Any reason why that shouldn't work as a lost-wax burnout furnace?

If 3 hours in that silly little 500˚F hotplate burner has worked reasonably well for me, why shouldn't 1-2 hours at 1100˚F in my charcoal burner? I would create some kind of steel screen compartment to protect the flask/mold from flying charcoal/ash debris. Any thoughts?

To burn out the wax pattern you should have a controlled heat of approx 1200 degrees.The investment can get burned it the tempature is too high or it could have residue if the temperatur is not controlled. A great book on lost wax is Lost Waxor investment casting Author James e sopcak Amazon.com has this book for sale. It gives a great deal of information and illustrated on DIY construction of the necessary Furances burnout ovens and pressure casting equipment. Good Luck and be careful

I found a deal on a tiny little kiln on ebay for $200 that can reach 1500 degrees F. It doesn't have temp control, but last night I read that you can put a little strip of aluminum (beer can) in your kiln, which will melt at 1200 degrees F as an indicator of temp - which is the perfect temp for wax burnout. Nice.

I'm now considering rigging up an aluminum wire inside the kiln, that closes a relay, which connects the kiln to 110VAC. When the wire melts, the low-voltage relay circuit opens and the relay snaps to "OFF" - turning off the kiln. Mostly I'll probably just peek under the lid to see when that beer can strip melts, but an automated system sounds fun. I can't afford a $500 automated kiln right now, on top of everything else (vacuum pump, etc).

Here is my new kiln.. just shipped. I cant wait to get it:

Where did I put that fire extinguisher? Oh..ya..over buy Dave's new kiln.

Looks promising. Postings are light but often quality in these forums, in a weeks time you'll get some ideas thrown your way on this. And I'll be lurking over in the corner taking notes.

The oven you purchased should work . I highly suggest you look into the book i suggested as the price is very reasonable and the information is well worth it.

OK! I bought the book, used on Amazon for $5 - and why does 80% of the jewelry-related stuff I buy come from Arizona??

Thanks for the suggestion. I look forward to reading it.

Daverham wrote:
why does 80% of the jewelry-related stuff I buy come from Arizona??

HIPPIES! Ok, I'm joking, don't come and hunt me down in your VW Microbuses.
My brother used to live in Arizona and that's where he learned how to make silver and turquoise jewlery. He was an Old Hippie.

... and I have a microbus - when I'm not riding my bike, I'm driving that. Go figure.

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.

Ok, no more Microbus cracks.

I don't know about cones, I thought they were temp and time at temp indicators..