First arc-melted sample. 
My friend Max Whitby sent me an email about an arc melting furnace he had seen at a university in England.  It could easily melt even very high-melting metals, like iridium. 
 
It seemed like a device I could approximate at home using some things I had lying around.  The most important component was an old stick welder I inherited from the former owner of the farm buildings in my compound.  I've never learned to use it as a welder (my modern wire feed welder is much easier to use), but it's an excellent source of brute electric current when you need it (up to a couple hundred amps). 
 
After I got a nice big chunk of graphite from eBay, and some graphite electrodes from Farm & Fleet (my local farm supply store), I decided it was time to give it a try.  The furnace at the university had a vacuum chamber built around it allowing for melting of reactive metals without oxidation or other contamination.  I may go that route some day, but for a first proof of concept experiment I just did it in the open air. 
 
I cut an approximately 2"x2"x1" block of graphite, hollowed out a cup in the middle, and clamped the ground electrode of the welder to it.  Then I placed my metal sample in the cup, put on a welding helmet, and touched the graphite electrode to the sample.  After a bit of practice, I could easily bring the whole thing to white heat in a couple of seconds. 
 
Judge for yourself whether I was successful in melting the iron: This thing used to be a 7/16" hex nut. 
 
Source: Theodore Gray 
Contributor: Theodore Gray 
Acquired: 27 April, 2003 
Text Updated: 11 August, 2007 
Price: Donated 
Size: 0.75" 
Purity: >95%
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