Niter Posted July 14, 2008 Posted July 14, 2008 MnO2 + Al -- 7 : 3 (slow burner)Cr2O3 + Al -- 8 : 3 (hot burner)Pb3O4 + Al -- 9 : 1 (flashes) and of course: CaSO4/Al (flashes)CaCO3/Al (flashes) BaSO4/Al (flashes)
starlight Posted July 14, 2008 Posted July 14, 2008 I tried a thermite with Kno3 60 sulphur 10 Pb3O4 20 Silicon 10 what do you think?
Rob Allen Posted July 16, 2008 Posted July 16, 2008 Hey guys if you added copper sulphate to the Al S thermite would you think you could get a blue flame? I don't have per chlorate and wish to make blue stars, little help?
GalFisk Posted July 16, 2008 Posted July 16, 2008 No. Blue requires a chlorine donor, and low flame temperatures. I think there exist some (inferior) KNO3 blues, but for good ones you need a (per)chlorate. The sulfate mixtures wouldn't technically be thermites, since the combustion reaction doesn't consist of a reactive metal reducing the oxide of a less reactive one.They're still fun though.
Rob Allen Posted July 16, 2008 Posted July 16, 2008 Hey mate thanks for that, I know it's the wrong thread but I've seen some of the KNO3 blue mixes posted, you wouldn't be able to tell me the best of the crap KNO3 blue, mix/ratio... Cheers.
Niter Posted July 16, 2008 Posted July 16, 2008 Hey guys if you added copper sulphate to the Al S thermite would you think you could get a blue flame? I don't have per chlorate and wish to make blue stars, little help? Sweet Mary and Joseph, using Al/S for stars is a particularly bad idea. Al/S burns to Al2S3 (aluminium sulfide) which by action of atmospheric moisture slowly releases highly toxic and extremely foul-smelling hydrogen sulfide. You would have a situation where your audience goes oooh and aaah looking at the fireworks and then go oooh and aaah as their clothes start to smell of rotten eggs. And real Thermites make the worst possible stars as slag of molten metal would rain down on your audience. Aluminium and Sulfur can be used in stars when combined with Potassium nitrate (and a dash of boric acid) though as this will burn the sulfide to sulfate, losing its stench and toxicity. Potassium nitrate.....50Sulfur.....................25Aluminium...............20Dextrin.....................3Boric Acid..................2 This would be more like a star formulation.
Richtee Posted July 16, 2008 Posted July 16, 2008 Sweet Mary and Joseph, using Al/S for stars is a particularly bad idea. Spoken like a true IRA pyro...LOL!
Rob Allen Posted July 16, 2008 Posted July 16, 2008 Woha Dude mary and Joseph have nothing to do with it, I hope. I asked first for this reason, thank you. I didn't mean Al S alone, my bad... Yeah, cooler temperate for blue not hotter. I'm new at this and although I'm not a pyrotechnition and I may get things wrong on posts, I make sure I'm 100% sure of what I'm doing before I do it, which is partly based on from input from what you guys say, so helpful answers welcome. Cheers.
FrKoNaLeaSh1010 Posted July 17, 2008 Posted July 17, 2008 This doesn't really have to do with thermite but a pale blue/teal can be made using bp/zn i believe it was 75/25. It is known as akwapo stars after the inventor Po. It is in the composition section of the site so I would double check the ratio there but it does make a pale blue with a slight green hint and is kno3 based.
flying fish Posted July 20, 2008 Posted July 20, 2008 I tried the standard 3:1 Fe2O3:Al mix for the first time today just for the fun of it. I had bought the Iron Oxide for glitter effects (win 25, 26) and possibly some primes later on...but then realized..."oh, yeah, there's something else fun I can do with that!" However, 4 grams of the mix, when using bright flake Al seemed rather unimpressive. It wasn't much brighter than the sparkeler that I used to ignight it, and on top of that, it failed to burn through the full pop can I had sitting right on top of it. I guess I will have to try it in larger quantities to get more of an effect...in addition to using less reactive aluminum (spheroidal) since I'm paranoid about being showered with molten iron (again, I haven't worked with thermite before, so I don't know what to expect). If I recall correctly from way back in the High School demo, the Al used was much coarser than most of the Aluminums than we use in pyrotechnics (maybe more like "firefly" aluminum granules), hence my concern that something might explode while using fine aluminums rather than just burning "peacefully." Edit - was looking back in this thread and it appears 200 mesh or finer is usually used anyway...So I guess I'm not too worried about it too much. I will try the atomized Al though...
Rob Allen Posted July 21, 2008 Posted July 21, 2008 Hey flying fish, you got any vids of flying fish shells??? I take it it's your speciality since thats your name... I made one once and it worked really well, I didn't tape it so I'm gonna make another but I want to see others Anyone else got em?
flying fish Posted July 21, 2008 Posted July 21, 2008 Actually, I created the flying fish screen name mostly as a tribute to the old mario games (and there was a seafood restaurant called "flying fish" that I used to go to, hehe). I honestly don't know much about the fish effect and have only experimented a little with flying fish fuse. My first shell actually did use the flying fish fuse and was "unfortunately" not caught on tape...but wasn't very impressive anyway. However, here is a video I had found on youtube from someone else that demonstrates a pretty impressive use of flying fish fuse:
Rob Allen Posted July 21, 2008 Posted July 21, 2008 Ah ok, no worries. Yeah that you tube one looks real good I can't make the green unless I make a cell, I can't be stuffed with that so I'll stick to glitter
FrKoNaLeaSh1010 Posted September 2, 2008 Posted September 2, 2008 I was just watching a tv special about fire weapons and they had a section on thermite. They were talking about the standard iron oxide and aluminum thermite but they used an uncommon method of igniting it. They said it was an easily ignitable mixture of barium oxide and magnesium. So pretty much they used a thermite to ignite another thermite. the barium oxide/magnesium lit with a match and produced beautiful green sparks before the iron oxide/al thermite ignited, Does anyone have any experience with barium oxide thermites? Naturally barium compounds are rather toxic but the green sparks looked pretty good and i was thinking about making some barium oxide to try this with but figured i would ask if anyone has ever made any or has any info on ratios or any other info about it. The color and ignitability from a match are very appealing.
tentacles Posted September 3, 2008 Posted September 3, 2008 (edited) I'm not sure barium compounds are a smart thing to play with, but you'd almost certainly have to reduce the Ba with another more reactive metal (or organic). I'd be willing to be what they used was actually barium peroxide, something you can order from firefox... http://en.wikipedia.org/wiki/Barium_peroxide If you're looking for ignitability from a match, just make up some meal/NC prime slurry, toss in a few bits of Mg (I have a tub of those curls from firefox) and goop on a dollop of that. Or make just about any hot meal prime and dollop that on with NC. Take some meal and toss in some Mg or Ti, make NC slurry with it. If you like not burning the crap out of your fingers, you can stick a piece of visco in the prime while it's still goopy, and let it dry. You could probably achieve similar results using strontium peroxide as well, although I doubt you'd get a vivid red color (it is possible though). Firefox sells that too. Edited September 3, 2008 by tentacles
FrKoNaLeaSh1010 Posted September 3, 2008 Posted September 3, 2008 (edited) I am well aware of how to make thermite ignite easier. If i really wanted it to ignite that easy i wouldnt even use a flame ignition i would use a kmno4/glycerine reaction to ignite it or just use magnesium ribbon. the appeal was the fact that it made nice green sparks and the thrill of experimenting with a new thermite. I have made tons of different thermites ranging from copper oxide, manganese dioxide, V2O5 and a bunch others but never thought of using barium or strontium for colored thermite. Also the toxicity of barium doesnt scare be at all as i have all the proper lab equipment and have worked with barium compounds before. Also after you've been within 5 feet of hydrazine and other severely toxic compounds barium just doesnt seem that scarey. If it was indeed the peroxide i dont know why a world renown explosives expert from england would say "barium oxide" instead of barium peroxide especially when he was going into very good detail about the thermite formula and ratio. If anyone has heard of him it was Dr. sidney alford i believe and i have seen him on numerous different tv specials and programs as an authority on everything from thermite to very high order explosives. There was another show i seen with him where he went very in depth on shaped charges and the munroe effect and all that so i would assume he knew what he was talking about and wouldnt say it was barium oxide if it was barium peroxide. I have never worked with metal peroxides so i dont know much about them but if anyone has experience with barium oxide or the peroxide please let me know as the barium oxide would be a lot easier to make than the peroxide and i am not looking to buy more chems as money is tight at the moment. Edited September 3, 2008 by FrKoNaLeaSh1010
FrankRizzo Posted September 3, 2008 Posted September 3, 2008 (edited) If you want a cheap barium compound that will react violently with a reducing agent like magnesium, look no further than barium sulfate. Is not nearly as exothermic as the other sulfates like magnesium sulfate (epsom salts) or even calcium sulfate (plaster of paris), but it does give quite a show. In fact, the barium sulfate/magnesium reaction is used for strobe pots, the additional ammonium perchlorate used to bring the combustion temperature up to the sufate's reactivity temperature. Edited September 3, 2008 by FrankRizzo
Miech Posted September 3, 2008 Posted September 3, 2008 Wasn't it the reaction between ammonium compounds and magnesium which has caused some fires in the past? I wouldn't like to make such a composition, let alone storing it for extended time.
FrankRizzo Posted September 3, 2008 Posted September 3, 2008 Wasn't it the reaction between ammonium compounds and magnesium which has caused some fires in the past? I wouldn't like to make such a composition, let alone storing it for extended time. Absolutely. Using the wrong ammonium compound (ex. ammonium chloride) with a fine reducing agent like magnesium is indeed a very bad idea. However, ammonium perchlorate can be used in comps with magnesium as long as the magnesium has a protective dichromate coating. You may be confused though, I wasn't advocating ammonium perchlorate with magnesium. Instead, I was stating that barium sulfate and magnesium make a fine combination for a high energy reaction with no other chemicals needed. *In strobe pots*, ammonium perchlorate is added to prime the sulfate reaction.
FrKoNaLeaSh1010 Posted September 3, 2008 Posted September 3, 2008 I am well aware of the sulfate strobes as i went through a phase of making magnesium based strobes a couple years back. I was more interested in the thermite reaction though. I will never forget the first time i made thermite i made 100g of red iron oxide/aluminum and ignited it on wet pavement and it left a little glowing iron ball on the pavement that i kept as a momento. If i were to make a barium based thermite it would in theory leave me some molten pure barium if it doesnt vaporize. I was only interested in it because i dont have much chems left but i do have about 2 ounces of barium nitrate that i could have converted to barium oxide to make this with. I am just trying to utilize the rest of my chems which arnt very many. I would just use the bano3 for stars but i dont have any kclo4, chlorine donors, or red gum. All i have for pyrotechnics are bp chems and a small amount about 2 ounces each of bano3, srno3 CuO and magnesium. I like CuO/Mg thermite and made some the other day and then when i seen the tv show about the barium thermite it just made me interested into making a different one to use up the barium salt that i have. and i gotta admit it was quite vigorously burning throwing green and white sparks and looked rather amazing. almost like a mini colored fountain and i;ve never made colored fountains only the basic charcoal, iron, aluminum based ones or ones with micro stars so something on the ground throwing colored sparks was appealing to me as i like doing things i havnt done before. Would anyone happen to know the stoichiometric ratio of BaO/Mg? Or any info on converting barium nitrate to the oxide. I would assume heating it would lead to thermal decomposition to the oxide but I have been out of chem for a couple years and unfortunately dont remember a lot of what i used to....perhaps i need to break out my old chem textbooks.
Mumbles Posted September 3, 2008 Posted September 3, 2008 There is always "thermate". It is made with barium nitrate and is flame/fuse sensitive. To convert to the oxide, the easiest way is probably to convert to the hydroxide and decompose it thermally. Water vapor given off, no nasty NOx. Stoichiometry would be 1:1
Richtee Posted September 3, 2008 Posted September 3, 2008 If you want a cheap barium compound that will react violently with a reducing agent like magnesium, look no further than barium sulfate. OK Frank...I thought I'd try this out... interesting stuff. Soo..I don't have mag, but I have magalum. Mixed 10 grams total 1-1 and poured into a Dixi cup on top of a pop can. Stuck in some visco coiled on the inserted end. Ffffff----tt... nothing...wait... a second after the visco got to the mix, BalOOOOIE... crushed the can and scart the SHEET outta me...what gives?? Self containing??
Miech Posted September 3, 2008 Posted September 3, 2008 You actually made flash. It's a sort of photo flash I've used a couple of times, working with aluminium (dark), magnesium and obviously also magnalium. Magnesium gave the fastest burning mixture, while magnalium produces way more light output. It's quite impressive stuff if made with airfloat barium sulfate and -625 mesh magnalium, it actually scared me. It doesn't seem very sensitive, but it just seems like that.
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