tantalum arc torch

so I was practicing some stainless steel welding using some scraps I found in the steel drawer.  Some of the triangle pieces I found wouldn't make good welds, no matter what I tried.  I started asking around, and someone recoginized the shape as tantalum.  Tantalum has a pretty high melting point, so I'm thinking of trying a tantalum arc torch.  It's not as high as carbon, but it might have better thermal conductivity.  I suspect it might react, but hopefully that won't reduce conductivity.  I'll let you know how it works out once I try.

carbon

so, carbon melts at over 6000 degrees F, and as you can see below my torch is melting it. Actually the pictures are all shortly after turning it off. Nonetheless, I estimate the temperature is more like 9000 degrees, based on the research I've done. This is actually hot enough to vaporize the carbon. Some further trivia, these rods are elementally the same as diamond, and this is one technique they use to create fullerenes, carbon nanotubes, and such.

I started out sharpening the carbon in a pencil sharpener, though for the positive side, that just caused faster melting. My advice is only sharpen one side, especially with a dc powersupply.
I found an excellent source of carbon, hopefully it will show in the attached image. I just cut open a 1.5 volt heavy duty battery and found 4 cells inside, each with it's own carbon rod. I got this battery out of a recycle bin. I think anything that says Heavy Duty, or Extra Heavy Duty will work, and EverReady is a popular brand. Expensive batteries have different reactions going on and don't have any carbon.

carbon arc torch, last try

so, here it is, the awesome carbon arc torch. I had trouble coordinating the arc strike and picture take time, and the positive side is quite melted. The carbon came from an EverReady D cell battery, and the rest was scrap, with the exception of the electrical connectors, which I bought from Roberts oxygen.
This website is really giving me some trouble. Also, it's really hard to capture the black body radiation, like glowing red with the camera we have here in the lab, but hopefully you'll get the point.
here are links to all the pictures in large format:
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winding coils and transformers isn't for humans.

So I decided to try and wind a power transformer as my other ones are broken, and I don't have much to do at work with out one.  We have a nice coil winding machine which I thought would be nice to use.  After getting it all set up and glueing all the wires in place after winding I test to make sure the wire isn't broke, and plug one end into the wall and the other into the volt meter.  When I flip the switch I hear some buzzing and then my coil bursts into flames.  I look and see that the light on the soldering iron is still on so I know I haven't tripped the circuit breaker, so I un-plug the transformer and blow the fire out.  the leads turned from copper color to black, and the side of the volt meter got charred too.  As such, from now on, if possible I"m buying transformers and coils if I need them, unless I'm keen on seeing some fire works.