How to choose an alternate wire?

[kickflipsnnollies]

I was at my local B&M the other day and a guy came in who had a spool of 34g steel beading wire he was using to vape with. He had triple-twisted it to get a decent resistance in his kayfun. I didn't hit any of his stuff, but it got me thinking as to how safe that might be.

What exactly are the properties we need in wire?

Obviously it needs to provide an adequate amount of electrical resistance and have a pretty high heat tolerance. But what numbers should I follow exactly? How hot does a super sub-ohm vape (I would base everything off of the hottest temps that might be encountered) tend to get? I know to avoid lead and other metals that might be harmful in my alloys. Any weird metals I might not think of to avoid, or to definitely have in my alloy? Anything that's gonna make it not malleable enough to work with?

Now I'm perfectly happy with my Kanthal A-1, but I also like to play around a lot, especially when it's cheap. I'd rather get some background info first to keep myself safe though.

Thanks in advance for any answers or comments!

 

[State O' Flux]

When heated, Kanthal wire (iron-chromium-aluminum) produces a self-generating, protective oxide layer called aluminum oxide or alumina (Al2O3). This insulative layer is both thermally conductive and electrically resistive - it protects the inner, electrically conductive iron-chromium content from corrosive elements... and prevents the individual coils from shorting, one to another.

This is most clearly noticed when you test fire a new, compressed coil... the coil initially shorts and heats unevenly. The more you fire it (and shape it to final perfection) however, the more evenly it will heat - from the hot center out to the cooler ends.
This is the alumina layer developing and insulating the coils surface. Although the coils are "touching", the electrically conductive component of the coils are (again) insulated by the alumina coating.

Other wire metallurgies can function as a resistive or Joule heating element... but without the properties that make Kanthal so unique, and so elegant for our needs.