I take no offense.
And thermites are USUALLY steady-burning materials, they burn extremely hot, but they don't produce gas, they certainly produce no shockwave (CuO/aluminium metal thermite is the exception, this does explode, violently, apparently although I've never done it, and cannot ever see nyself needing to do so since I have zero need to take such measures in order to obtain a sample of metallic copper, its everywhere, all I need are a few bits of wire and a torch, or save the replacement extension wires I solder on to those of my power supply since they frequently end up fusing solid.
What I didn't realize, and I had asked at a forum for like-minded folk about the characteristics of manganese dioxide thermites, is that the metal is produced in the form of a gas, it vaporises. I queried using manganese oxide hydroxide, was told it was unsafe so I roasted that hydroxy-oxide on its own (with no reducing agent) to convert it, (perfectly safely) to manganese dioxide. Queried and got no response until AFTER reporting the speed of the propagation of the reaction. The classic thermite is iron oxide (Fe2O3 type, usually, red iron oxide) which is, like most kinds, steady burning, but extremely intense. I KNOW not to look at thermite whilst its going without protective eyeware. And I was wearing at the time, since it was being done at night in order not to cause a disturbance, just a facial blast shield, it isn't tinted although protects the face, head and neck, right down to the chest, from flying sparks, bits of chipped glass should they ever occur to a user of such a shield, acid or alkali mist spray caused by the localized boiling of say, alkali metal hydroxides or concentrated sulfuric, nitric acid etc. dissolving in water, which is very exothermic and can make the liquid boil, throwing up small quantities of acidic/alkaline mist, which is not generally enough to be even annoying, unless it were to get into somebody's eyes, elsewhere its likely I won't even notice it.
As for 'accidents like that can't happen', what would be correct is 'every precaution should be taken, and indeed must be taken to avoid forseeable risks' not 'accidents can't happen'
Accidents can happen and they do happen. Industrial plants and professional laboratories have accidents. There have been liquid helium leaks at the large hadron collider for example, and a particle accelerator complex like that costing tens or even hundreds of millions of dollars with the most experienced, knowledgeable folk in their fields available, it still has the potential to happen. Or nuclear reactors, like the fukushima and chernobyl fires. Or the so-called 'demon core' a plutonium pit (a pit is the two halves of subcritical fissile nuclear material which when fused together by the powerful shockwave of an atomic bomb's initiator explosive charges, be it by firing them together down essentially, a long pipe like bullets, in some uranium devices or in the case of plutonium, being surrounded by shaped charges and imploded, likewise in hydrogen bombs (deuterium-tritium mixture is placed in a capsule at the enter of the pit, of a conventional fission bomb, the implosion plus the massive energy released during fission of the nuclear primary ignites the nuclear secondary) one was being studied, outside a bomb, within a stack of tungsten bricks, and accidentally, it dropped, contacting the other half of the pit, and for a fraction of a second to second or two went critical, it didn't cause a nuclear explosion but it did go critical, and it irradiated and killed people in the room doing the studies.
Accidents CAN happen. Accidents DO happen. One doesn't WANT accidents to happen but they do, which is why they ARE 'accidents' rather than 'hey I just deliberately caused a fuckup and dived into a woodchipper in a graceful swan-dive off a tree branch backflipping along the way' or 'hey I just went and poured myself a glass of fuming nitric acid, knowing precisely what it was, and drank it for fun, knowing it would burn me alive from the inside out in an agonizing, cruel, horrific slow way to die'
See what I mean? if you have a foulup in any conditions, could be washing dinner plates and the soapy hands make you accidentally slip and drop the plate, even with rubber gloves on, it can and does happen. Doesn't mean you don't make every effort to prevent it happening.
Thankfully my eye is feeling a little better. And 'arc-eye' hurts like crazy, its self-limiting however unless someone were to be really, really stupid.
Or for another example, take Albert Hoffmann's serendipitous discovery of the properties of LSD for the first time, opening up, more or less, an entire field of research. That was an accident, caused by absorption of a miniscule quantity somehow, of which he was unaware until bicycling home, and beginning to feel most strange in a unique way, of lysergic acid diethylamide, one of a large series of ergot alkaloid derivatives semisynthetically derived from ergotamine, and other ergopeptides, which themselves are toxic. He was a careful, meticulous chemist, and although in his case the discovery was made possible by the exceptionally high potency by weight of LSD. He then the next day, carefully went through everything he had worked with that previous day, and ingested, deliberately, tiny quantities. IIRC he started off with one quarter of a milligram of LSD in an effort to search for and discover exactly what compound he had created which he had accidentally absorbed a probable couple of hundred micrograms down to maybe 50-75mcg or so (for comparison IIRC a grain of table salt on average weighs about 200mcg). He had, he found out, in that 1/4th of one milligram of the twenty-fifth compound in his series of compounds, lysergic acid diethylamide, ingested (deliberately) what he thought to be a dose likely without activity and slowly work it up until an active dose was reached over many smaller increments. Yet it turned out to have a most powerful effect, as 1/4mg of acid is a dose thats pretty strong.
That first dose level being active, was accidental, he believed it a dose that would be too small to possibly exert an effect. And he was in fact, after respiratory stimulant drugs for hospitals and paramedics, as well as investigating uterotonic effects of ergometrine (aka ergostetrine depending where you hear the compound spoken of), ergotamine etc.
That was benign, he had an experience he considered truly astonishing and most certainly worthy of research, but the actual fact of the first deliberate dose of LSD-25 he took, after accidentally somehow absorbing a trace quantity and experiencing subtle but definite effects whilst going home, flowering on his perceptions, he believed it would possess sub-active levels were it the active compound itself. It didn't. Not by a long shot, and it was, despite his being a knowledgeable pharmaceutical chemist of meticulous and thorough nature, nevertheless, not deliberate that upon that specific trial it should show bioactivity straight up off the bat.
All anybody can do is exercise the greatest care possible. For example, I make sure to be clean and smooth shaven every time I work with something particularly toxic if it is volatile in the slightest, if I need a mask at all, I shave immediately before donning it, to ensure a tighter seal between mask and face, I make sure the straps are tightened right, its sat at the right angle on my face, I test the outlet seal, I clean and dry the mask unless it has been cleaned and dried since the previous use, and I also test the seal between mask and face by means of hands over both canister intakes and then testing to make sure it'll hold a vacuum when breathing in momentarily.
ALL anyone can do, is be as careful as they can. And I've worked with far, far, far nastier things, that give no second chances, compared to which thermite is a pussycat, regardless of the metal/oxide. In any care, my eye is feeling somewhat better now, although I'll be wearing an eyepatch for the next day or two, and it still hurts like a bastard. Although the pain meds are helping, I can, now, open my eye with the patch on.
With the darkness of the welding visor I have, you can't even SEE out of it in daytime, bar illumination from an intense flame, so its quite hard to work with, in the dead of night there is no way anyone would stand a cat in hell's chance of seeing anything but a welding torch flame, electric arc etc already struck, or a thermite lit already. So I was using a clear visor and intending to light the mixture and turn away, simply listening for the sound of the reaction (a hissing, spitting crackling sparking noise with somewhat of a 'whoosh'.
They (copper oxide of the type CuO aside, and nanopowder composite thermites excluded) DON'T generally explode, and neither did this, it didn't detonate, it behaved like for example, black powder (gunpowder) or flashpowder (Al or Mg dust and a perchlorate or sometimes nitrate such as potassium nitrate) not placed into a casing, but sprinkled over a piece of paper, out in the open in a small pile (small enough in the case of Al or magnesium flashpowder not to self-confine under its own weight), and then lit, so all it does is burn rather than explode, for which it needs a casing, or in the case of flash compositions such as those used in 'banger' fireworks (theres about 50-100mg aluminium flash comp in most commercial little red bangers (you know, bigger than a chinese cracker on its own, a tiny fraction narrower than a centimeter in diameter, rounded, about 2 and 3/4 inch long and with a stubby, rather thick fuse thats difficult to ignite?) the mixture in those is flashpowder, in the firework it'll go off with a loud bang, if the same quantity of identical powder were to be allowed to be removed, as I found out as a kid, from the firework, being that its not a high explosive, which propagate detonation via a supersonic shockwave severing chemical bonds and releasing great amounts of energy in the process, but whats known as a low explosive (these deflagrate, or burn fast as hell without detonating, producing great amounts of gas very quickly, but don't possess the same degree of brisance (shattering effect) that the shock-front of a HE does) if initiated without being confined spatially, such as poured on a sheet of ordinary paper all it does is go 'poof', its just a mixture of a fuel and an oxidizer, rather than often being part of the same molecule too. Not that HEs cannot ever be binary comps, they can (panclastites being a classic example, or astrolite, based on hydrazine although both are not these days used for E.g mining or militarily, especially the panclastites which are notoriously dangerous)
Myself, I don't do pyro these days, did as a kid, got plenty knowledge about it but its not something I actually do practically, I just still have the knowledge accumulated by past experiment and both past and present reading. And, through needing to know about potentially explosive reactions, which aren't intended to be explosive, so as to be able to avoid creating such conditions accidentally.
https://en.wikipedia.org/wiki/Thermite for a description.
The thermite reaction is somewhat of a singular exception, as some elements are very difficult to obtain from their ores, oxides, sometimes halides, and the use of a more reactive metal with a lesser reactive metal oxide or some other compounds (Al/calcium sulfate (gypsum) is an example of a nonconventional type) that whilst not meant to explode (cupric oxide excluded as I mentioned prior) and is useful for such refining of metal ores.
I just did not know that in the case of manganese the reaction is hot enough, with Mg/manganese dioxide to boil the metal as its produced and vaporise it, and quite how fast it occurs. Now I need to look into a housing for a crucible that will take the heat, made out of something like thick stainless pipe, open ended so as not to be able to confine the gas and as such not capable of explosion, and act like a giant condenser, with something like a pair of copper liners and a water jacket made out of copper with a pair of pipe connecters leading to it, fed by the hose, perhaps initiated by an internally created electric arc from a high wattage power source. Essentially like a glass liebig type lab condenser, but large, heat resistant metal, and curled round to collect the manganese sample for my collection, which can later, once enough, doing a few grams of mixture at a time (this was IIRC a couple hundred milligrams short of 3g), the manganese metal can be melted with a propane, or if needs be an oxyhydrogen torch whilst wearing a gas mask with particulate filters to protect against manganism (its toxic especially if inhaled, causing neurodegenerative disorders and parkinsonian type toxicity) so careful, I was. I just looked at it not knowing how fast the flame propagates.
And of course, this wouldn't 'blow up my house', it wouldn't blow up anything, not being confined, lit in an open crucible as a test more or less. And it was done outside, as all such intensely hot reactions are if they don't just sit there (like for example using my molten metal bath, that is alright indoors provided good ventilation owing to the lead etc.) And as are other reactions involving chemicals I deem too dangerous to use indoors.
