Quick And Easy Thermic Lance Is Hot Enough To Melt Rocks

Heat can be a hacker’s best friend. A little heat can help release a stubborn nut cleanly, and a lot of heat can melt a rusty bolt clean off. An oxy-acetylene torch is handy for these applications, but if you need a more portable setup, and you want enough heat to melt rocks, you might want to look into this field-expedient thermic lance.

Thermic lances have been around a long time in the demolition industry, where cutting steel quickly is a common chore. Commercial thermic lances are just a bundle of steel fuel rods which are set on fire while oxygen is blown down a consumable outer tube. The resulting flame can reach up to 4500°C with impressive results. In need of a similarly destructive device, [NightHawkInLight] came up with a super-simple lance – a small disposable tank of oxygen and regulator, a length of Tygon tubing, and a piece of 5/8″ steel brake line. No need for fuel rods in this design; the brake line provides both fuel and oxygen containment. As you can see in the video below, lighting the little lance without the usual oxy-acetylene torch is no problem – a “wick” of twisted steel wool is all that’s needed to get the torch going. The results are pretty impressive on both steel and rock.

You say you’re fresh out of brake line and still need some “don’t try this at home” action? No problem at all – just hit up the pantry for the materials needed for this tinfoil and spaghetti thermic lance.

[Thanks, funebre]

42 thoughts on “Quick And Easy Thermic Lance Is Hot Enough To Melt Rocks

  1. i was wondering how i was going to cut up that roughstock for later use, this gave me an excitingly fun way to do it, i wonder if the oxygen flow from expired medical bottles will do, only one way to find out.

    1. Oxygen is oxygen. Medical grade simply means it has no contaminants or a far lower amount that welding grade. If you can get hold of an oxygen concentrator that still works, it can be used for light duty welding. Jewelers love them, hook up to an O2 concentrator and a gas pipe for cheap and endless torch power.

        1. What makes the tank expired? It seems the tank was full with a stuck valve and the employee tried to use a wrench to open the valve enough to let the oxygen bleed out.

          The same danger presents itself when said cylinder is on a cart following a 90 year old smoker or when a much larger oxygen tank is sitting behind a welder.

          1. The valve itself was stuck, and the workshop man was trying to take off the valve assembly from the head of the tank.

            Cylinders are “off” when they no longer pass safety checks, and the degradation of components means that a valve-closed or valve-open failure may only occur once the cylinder is pressurised.

            The smoker is likely to set his home on fire (and most sane companies refuse to rent cylinders or concentrators if there is a smoker in the home) and will certainly have a set of safety-checked valves.
            The welder would also insist on inspected tanks.

            “Expired” tanks would not be in either of those examples, and oodain specifically mentioned expired bottles.
            My point was that would be in advisable, and who would have thought that merely trying to loosen a valve assembly from the top of a tank, without external heat or spark, would result in an explosion, a fire which melted steel, brass, and the severing of a firearm.

    1. I never liked macguyver, it’s all such unscientific and impossible BS, but since you and some others might I can tell you I recently saw a headline that they are probably going to make a new macguyver series, and wikipedia seems to suggest the new one will be a woman.

        1. Well there was no need to go as far as they did in macgyver IMHO, things like taking two pieces of a mirror and the hold them just right in the sun to crate a laser to cut through things at long range, I mean you can use more realistic science and still have a show.like macgyver.

          It’s the same as with the CSI shows, once you start showing two people typing on the same keyboard at the same time to make a VBscipt to hack into a computer or some such silliness you just went too far with your comedy.for a show not meant to be a comedy.

          But macgyver was meant for kids some might argue, but that’s my beef, you should respect kids a bit and not put too much nonsense into their heads in my personal view. But that’s just this guy”s view. Take it or leave it.

      1. Are you thinking you are clever enough to coax us into a ruse? Please Whatnot. We haven’t seen a single positive contribution, suggestion or point out of an systemic error to warrant your opinion of MacGuyver.

        Tl;dr – This CYKA, never even watched SG-1

    1. I agree but i think the bottle will have one already? I might be wrong. Also I would use stainless steel shower tubing instead of the plastic, It’s quite cheap and isn’t going to melt on contact with a spark.

    1. Technically I think an explosion (or at least a detonation) has to propagate at the faster than the speed of sound, but as long as there is a local increase in air pressure, you’re good.

    1. no, you need the high oxygen content to oxidize the steel fast enough to get a decent amount of heat. at atmospheric composition you would have all that inert nitrogen preventing your reacting and carrying that heat away.

  2. Does anyone know how copper or aluminum tubing would behave? I saw an article that stated that iron burns via exothermic oxidation of the molten part. Copper is listed as having low-flammability but burns in the same mechanism as Iron. Aluminum has high flammability and burns from the aluminum vapor at the flame end..

    1. I saw a reference to some commercial thermic lances that use aluminum fuel rods for higher temperatures. Think about it – aluminum and iron burning together is basically thermite…

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