With most of the apparatus and instruments we now take for granted yet to be developed, the early pioneers of the Electric Age had to bring a lot to the lab besides electrical skills. Machining, chemistry, and metallurgy were all basic skills that the inventor either had to have or hire in. Most of these skills still have currency of course, but one that was once crucial – glassblowing – has sadly fallen into relative obscurity.
There are still practitioners of course, like [2SC1815] who is learning how to make homemade incandescent light bulbs. The Instructable is in both English and Japanese, and the process is explained in some detail. Basic supplies include soda-lime glass tubing and pre-coiled tungsten filaments. Support wires are made from Dumet, an alloy of iron, nickel, and cobalt with an oxidized copper cladding which forms a vacuum-tight seal with molten glass. The filament is crimped to the Dumet leads and pinched into a stem of glass tubing. A bulb is blown in another piece of tubing and the two are welded together, evacuated with a vacuum pump, and sealed. The bulbs are baked after sealing to drive off any remaining water vapor. The resulting bulbs have a cheery glow and a rustic look that we really like.
Of course, it’s not a huge leap from DIY light bulbs to making your own vacuum tubes. That’s how [Dalibor Farny] got started on his handmade Nixie business, after all.