A: Please be careful if you’re trying to build your own. This isn’t simple kitchen chemistry of cobbled-together parts, if you want a torch that works well, and is safe. Remember that what the torch is doing is taking a substantial amount of electricity, which has plenty of risks and considerations of its own, and using it to generate a mix of oxygen and hydrogen. Handled wrong, that’s a rather potent and explosive mix. And to make the water electrically conductive, it’s mixed with highly corrosive chemicals.

Don’t forget you can’t just burn the oxy/hydrogen mix as is. It’s too hot, too combustible. The torches on the market all run the gas mix through a vapor fluxing unit to mix in the fumes of one of several common solvents, either with or without added boric acid flux. The result of all that is your nice usable clean flame. The commercially made torches do it right, and do it safely. But getting there is not as simple as describing what the things do.

Also, for the record, this is hardly new. The first one I ever used was in the mid 70s, not long after I first entered the commercial jewelry world after college. They’d been around for quite a while before then. The torches have, however, been refined since then, and one can get decent units for less money, that work better than the earlier ones. There are quite a number of different brands and versions around for your purchase consideration. L&R makes a great, though somewhat costly, workhorse of a torch. Spiraflame makes several versions, even costlier if I recall, but very high quality. Krohn industries makes one, I think, and those three are just the first names to pop into my head. There are at least three or four others I can think of, but their names escape me as I type this. A bit of net searching should be able to find you a number of choices, and I’ll bet you that buying one, at least one of the smaller units, would be a good deal cheaper than making one, if you value your time at all reasonably as part of the cost.

Just as an illustration, consider the humble electric motor. A good polishing motor costs perhaps a hundred fifty dollars. You don’t really even need to know how or why it works to copy the obvious features of the design if you’ve got one to take apart. But getting it right, so your own home-built version of a buffing motor runs, develops power, doesn’t short out, burn out, or make too much noise? Try building your own for less than buying one. I doubt even the geekiest among us could do it.