metal crucibles?

[Metalsmith21]

Ive seen "youtube videos" of some people melting zinc or sheet/cast aluminum in old cast iron skillets, pans, etc.

Is that a good idea? Its probably better than a soup can.

[BIGGUNDOCTOR]

Both of those are low melting temp alloys. We used a cast iron pot for melting lead for sinkers back home. I would prefer a thicker wall than a frying pan myself.

[arftist]

Cast iron or steel will work for aluminum but the molten aluminum will disolve some of the iron.

Usually good for practice, though I use cast iron molds for aluminum and they work well.

 

There are a lot of things to work out in casting so before a big investment like a crucible it is good to practice with what is at hand.

[Nobody Special]

I've used steel for aluminum. It will melt through if overheated and can fail after too much oxidation. Also, because of the oxidation issue, thicker walls is always better, and you may also get small inclusions of iron oxide in your casting. Using a soup can for a single melt......I did it...back when I didn't know better. It's a good way to end up with molten aluminum on your toes and legs.

 

Also, by the time you get around to casting zinc, you should have enough experience and equipment that you shouldn't be using a makeshift crucible. Don't just muck about with it. Usual warnings about fume fever.

[Qhforge]

I use a 4" od pipe with 1/4" walls and a 3/8" plate oxy/acet welded to the bottom as my crucible. They will slag out after a while but mine has lasted for 200 melts and looks like it can go for at least 50 more. But I am using this forge to do it and I place the aluminum directly under the flame, not the crucible.

[Glenn]

Ive seen "youtube videos" of some people melting zinc in old cast iron skillets, pans, etc.
Is that a good idea? Its probably better than a soup can.

Glad you ask first.

 

Zinc Melting point   419.53°C, 787.15°F

Zinc Boiling point   907°C,      1665°F

This is for elemental zinc, not the stuff you would find at a junk yard etc which may or may not be alloyed with other things.

 

Crucibles are designed for melting and holding hot liquid metals. Soup cans are disposable packaging.

 

Ask yourself, is it a good idea to reuse disposable packaging designed for room temperature to hold 1000*F HOT LIQUID metal? 1000*F or more, because you do not have the equipment to accurately control the temperature. If you did you would also have, and be using, the PROPER crucible designed and approved for the material being melted.

 

Look at the differences in shapes between the crucible and the skillet or pan. There is a reason for the shape difference.  Youtube has a wealth of information, and has much misinformation.  You must decide what is correct, and what is incorrect, before you put life and limb at risk.

 

IForgeIron pushes safety because we do not want anyone to be hurt. 

[oldgoaly]

skimmers and degasses bells are made of steel, the pot on my Johnson 313 soft metal melter is cast iron. It is recommended one use a graphite / plubago?  coating on the metal. I bought gallon of it from McEnglevan a number of years ago, they are relatively close so shipping didn't cost more than the stuff!