The Book That Could Have Killed Me

It is funny how sometimes things you think are bad turn out to be good in retrospect. Like many of us, when I was a kid, I was fascinated by science of all kinds. As I got older, I focused a bit more, but that would come later. Living in a small town, there weren’t many recent science and technology books, so you tended to read through the same ones over and over. One day, my library got a copy of the relatively recent book “The Amateur Scientist,” which was a collection of [C. L. Stong’s] Scientific American columns of the same name. [Stong] was an electrical engineer with wide interests, and those columns were amazing. The book only had a snapshot of projects, but they were awesome. The magazine, of course, had even more projects, most of which were outside my budget and even more of them outside my skill set at the time.

If you clicked on the links, you probably went down a very deep rabbit hole, so… welcome back. The book was published in 1960, but the projects were mostly from the 1950s. The 57 projects ranged from building a telescope — the original topic of the column before [Stong] took it over — to using a bathtub to study aerodynamics of model airplanes.

X-Rays

[Harry’s] first radiograph. Not bad!
However, there were two projects that fascinated me and — lucky for me — I never got even close to completing. One was for building an X-ray machine. An amateur named [Harry Simmons] had described his setup complaining that in 23 years he’d never met anyone else who had X-rays as a hobby. Oddly, in those days, it wasn’t a problem that the magazine published his home address.

You needed a few items. An Oudin coil, sort of like a Tesla coil in an autotransformer configuration, generated the necessary high voltage. In fact, it was the Ouidn coil that started the whole thing. [Harry] was using it to power a UV light to test minerals for flourescence. Out of idle curiosity, he replaced the UV bulb with an 01 radio tube. These old tubes had a magnesium coating — a getter — that absorbs stray gas left inside the tube.

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Mini Arc Furnace Melts Its Way Into Our Hearts

[Grant Thompson], aka “The King of Random,” threw caution to the wind when it came to his latest awesome project – a mini electric arc furnace (EAF) (YouTube link). [Grant] uses a refractory brick as a furnace and crucible for the molten metal.  He wears eye protection and a respiratory mask as he cuts up the brick – a good idea, since you don’t want to inhale any of that dust. The electrode grips are made with things you can find at a hardware store, including copper wire and coupling, and 2 pairs of vice-grip style pliers. The copper wire is stripped and attached to the metal handle of the pliers using hose clamps. The pliers are now functional electrode grips- just put a carbon rod in each grip and hold them close to each other…but not without protection! [Grant] harvested the carbon rods  from the cells of 6V lantern batteries – dead batteries work just as well for this. It’s also a better bet to do this outdoors with decent ventilation and away from anything flammable. [Grant] realized that the rods from the batteries have a wax-like coating on them that takes about 30 seconds to burn off in spectacular flames the first time they make electrical contact. However, you can purchase carbon rods by themselves if you want to avoid ripping open batteries and possibly setting yourself on fire. The mini EAF runs on a welding power supply [Grant] made from microwave oven transformers  (YouTube link).

When it’s time to melt some metal, the scrap metal is placed into a bowl drilled into the brick. Using the electrode grips, the carbon rods are placed into the brick’s pre-drilled holes. It only takes ten seconds to melt pure zinc – do NOT do this with galvanized steel or brass castings, as zinc oxide is very hazardous to your health.

In the videos featured below, [Grant] shows a variety of metals are no match for his mini EAF. He even manages to melt rocks from his backyard! It goes without saying that an EAF (video link) can be very dangerous. When you’re dealing with high voltage, plasma, white-hot molten metal, and toxic fumes, you better know what you’re doing (or have a great life insurance policy). [Grant] has a penchant for showcasing projects that can make an OSHA inspector cringe,  but you have to admire his gumption!

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