Article 7221 of rec.pyrotechnics: Path: ms!darwin.sura.net!mips!pacbell.com!att!ucbvax!teaching.cs.adelaide.edu.au!agbrooks From: agbrooks@teaching.cs.adelaide.edu.au (Zoz) Newsgroups: rec.pyrotechnics Subject: FAQ UPDATE - Comments Please! Message-ID: <9206010847.AA01062@dougal.teaching.cs.adelaide.edu.au> Date: 2 Jun 92 00:17:45 GMT Sender: daemon@ucbvax.BERKELEY.EDU Lines: 935 Well, here is the updated FAQ. Thanks a lot to everyone who sent me comments and help. I've added a comment prefixed by '--***' next to everything I've changed since the last one, so you don't have to read through the entire file again. Please reply with comments, corrections etc. again! Thanks! >>>>> 1. Introduction - Welcome to rec.pyrotechnics ============================================= Rec.pyrotechnics is a worldwide newsgroup dedicated to the discussion of fireworks and explosives, mostly concerned with their construction. The readers of rec.pyrotechnics welcome anyone with an interest in the subject, be they experienced or just trying to get started in the hobby. If you are just getting started, try to get hold of as much information on the subject as you can, and read it carefully. If it is explosives you are interested in, make sure you read up on the theory behind explosives. There is a lot of misinformation in movies etc. regarding explosives, so it is important you get a good background from a reliable source. In the Pyrotechnic Literature section below are several books that are must-reads for anyone serious about pyrotechnics. Try all your local libraries - even if they don't have the books mentioned below, they are sure to have some information on the subject. Remember, you can never be too well-informed - it is *your* safety that is at stake, and not being aware of all the aspects involved is extremely dangerous. Pyrotechnics and explosives are not safe - factories have been destroyed in the past, and they have access to the best materials and equipment, and take the most stringent safety precautions. Some people on the net have also been injured by accidents, and many of them had years of experience and took extremely comprehensive safety measures. Some knowledge of chemistry and physics is essential - if you didn't do high-school chemistry, get yourself a chemistry textbook and read it. Make sure you understand the basic principles involved for any composition you might be making. It is a good idea to check a recipe out with someone who is experienced in chemistry, to make sure you haven't missed any safety aspect. If you take the time to find out all the information, and put safety of yourself and others as your highest priority, you will find pyrotechnics an extremely fun and rewarding hobby. --*** added explosives aspect to the welcome, + more safety warning 2. Reading rec.pyrotechnics =========================== Often you will see an interesting composition or method posted to rec.pyrotechnics and the temptation is to run out and try it immediately. However, sometimes information posted will contain errors, or omit important safety aspects. Sometimes people will post methods that they heard from some vague source, or that they think should work but haven't tried. Leave it for a couple of days to see if anyone on the net responds to it. If not, get a printout of it and read it several times to make sure you are completely familiar with it. If you have any questions or corrections for an article, please don't hesitate to post. People on the net would much rather answer a question that may seem "silly" to you, than to see you get hurt. 3. Posting to rec.pyrotechnics ============================== If you have a composition or a method that has served you well, please share it with the net. Also if you have a question, people will be happy to help you out with it. However, please remember that you message is going to be read by a lot of people around the world, many of whom may not be as familiar with aspects of your posting as you are. Include all relevant safety information, for example possible mixing and storage hazards, toxicity, expected behaviour of the composition once ignited etc. If you post something you haven't tried, be sure to make that clear in your article. This is a good idea when asking questions as well - make sure it is obvious that you are asking a question, rather than posting something you don't know about and hoping someone will correct it. Read through your article before posting it to make sure that you have covered every aspect, and that there are no errors or ambiguities that could cause people to interpret part of it the wrong way. 4. Legal Aspects of Pyrotechnics ================================ Chances are that many of the procedures involved in pyrotechnics are illegal without a permit where you live. There are generally separate laws regarding storage of chemicals, manufacture of fireworks, manufacture of explosives, storage of fireworks, storage of explosives, use of fireworks and use of explosives. The laws regarding fireworks may also be split up in terms of the "Class" of fireworks concerned - commonly available fireworks are Class C, while the fireworks typically seen at displays will be Class A or B. Make sure you know where you stand in terms of the law in your area, and get a permit if necessary. Make sure that what you are doing will not cause any damage to other people's property, and that there are no innocent bystanders that can get hurt. There are plenty of laws relating to injury or damage to third parties and their property, not to mention lawsuits. We don't want anyone to get in trouble with the law because of anything here. --*** Legal section extended 5. PGI - Pyrotechnics Guild International ========================================= Pyrotechnics Guild International, Inc is a non-profit organization of professional and amateur fireworks enthusiasts: builders, shooters & watchers. Membership includes a quarterly journal and an annual convention. (Idaho (Fire) Falls, Idaho, 92) For membership information, contact: PGI Ed Vanasek 18021 Baseline Ave Jordan, MN 55352 You need either three reccomendations from random people or one reccomendation from a PGI member. Dues are $25., US. Another newsletter is American Fireworks News, monthly, miscellaneous news, technical articles, ads, $19.95/yr. AFN Star Rt Box 30 Dingmans Ferry, PA 18328 --*** info added 6. Pyrotechnic Literature ========================= 6a. Fireworks Literature ------------------------ These are extremely good books on the subject of pyrotechnics, and are really a must-read for the serious pyrotechnics enthusiast. Many others that are not listed here are also worth reading - check out your local library, Books In Print, Pyrotechnica Publications etc. for more references. Conkling, John A.: "Chemistry of Pyrotechnics: Basic Principles & Theory" (Marcel Dekker, New York, NY 1986. (ISBN 0-8247-7443-4).) See also Conkling's articles in Scientific American (July 1990, pp96-102) and Chemical & Engineering News (June 29, 1981, pp24-32). Shimizu, Takeo: "Fireworks - The Art, Science and Technique", 2nd ed. (Pyrotechnica Publications, 1988. (ISBN 0-929388-04-6).) Lancaster, Ronald: "Fireworks, Principles and Practice" (Illus.) 2nd ed. (Chemical Publishing Company Incorporated, 1992. (ISBN 0-8206-0339-2).) --*** updated Lancaster reference to 1992 reprint Weingart, George W.: "Pyrotechnics" (Illus.) (Chemical Publishing Company Incorporated, 1968. (ISBN 0-8206-0112-8).) Davis, Tenney L.: "Chemistry of Powder and Explosives" More references are available from Books In Print. By far the best source for all books on fireworks is: Pyrotechnica Publications 2302 Tower Drive Austin, TX 78703 USA 6b. Fringe Literature --------------------- These books usually deal with home-made explosives etc. more than fireworks, and are usually dubious at best. Most are not worth buying, especially if you are more interested in the pyrotechnics field. Much of the information in them is inherently unsafe - many of the books deal with field-expedient methods, and assume that some casualties are acceptable along the way. If you want to try anything out of one of these, it is a good idea to ask about it on the net or to someone experienced in pyrotechnics or explosives. "The Anarchist's Cookbook": this is in "Books in Print" so your local bookstore should be able to get you a copy. Alternatively, you can send $22 (includes postage) to Barricade Books, PO Box 1401, Secaucus NJ 07096. The Anarchist's Cookbook gets a big thumbs down because it is full of inaccurate information. "Ragnar's Guide to Home and Recreational Use of High Explosives": thumbs down as it is even more inaccurate than The Anarchist's Cookbook. US Army Technical Manual 31-210 1969 "Improvised Munitions Handbook": The Improvised Munitions Handbook generally gets okay reviews; it contains a whole bunch of recipes for making explosives etc. out of handy chemicals. You can get it from several sources, gun shows, or for $5 from Sierra Supply. "Poor Man's James Bond Vol. 2": mostly a set of reprints of various books, in small type. It does have Davis' Chem. of Powder and Explosives and what appears to be Vol. 1 and 2 of the Improvised Munitions Handbook series. Vol. 1 of PMJB has a reprint of Weingart's book Pyrotechnics (?) Here are some sources for the books. Catalogs from most of these places are likely to be interesting. Loompanics, P.O. Box 1197 Port Townsend, WA 98368. This company sells a wide selection of fringe books on drugs, explosives, war, survival, etc. Catalog $5. Sierra Supply, PO Box 1390 Durrango, CO 81302 (303)-259-1822. Sierra sells a bunch of army surplus stuff, including technical manuals such as the Improvised Munitions Handbook. Sierra has a $10 minimum order + $4 postage. Catalog $1. Paladin Press, P.O. Box 1307 Boulder, CO 80306 Delta Press Ltd, P.O. Box 1625 Dept. 893 El Dorado, AR 71731 Phoenix Systems, P.O. Box 3339, Evergreen CO 80439 Phoenix carries fuse (50 ft/$9), smoke grenades, tracer ammo, dummy grenades. Catalog $3. U.S. Cavalry, 2855 Centennial Ave. Radcliff, KY 40160-9000 (502)351-1164 Sells all kinds of military and adventure equipment. Thanks to Ken Shirriff, Phil Ngai, Keith Wheeler, Charles Marshall, Gary Hughes, and others. 6c. Net-Available Information ----------------------------- "The Big Book Of Mischief 1.3", commonly abbreviated TBBOM, is available via anonymous FTP at kalikka.jyu.fi. This is generally a compilation of articles from many sources such as 'The Poor Man's James Bond' and from here in rec.pyrotechnics. This also comes under the heading of 'Fringe Literature', as many of the items and methods contained in it are of dubious safety and reliability. --*** FTP site for TBBOM added - are PYRO1-4.TXT (The Gopher files) readily --*** accessible on the net anywhere? 7. Frequently Asked Questions ============================= Below are descriptions of several things that are frequently asked about on rec.pyrotechnics - they are not generally of much use in fireworks, but they are here to cut down message traffic on these subjects which have been covered many times before. First though, here are some safety rules. Read these and memorize them. 1. Mix only small batches, especially when trying something out for the first time. Some mixtures, particularly flash powder, will detonate rather than deflagrate (just burn) if enough is present to be self-confining. It doesn't take much to do this. Small amounts of unconfined pyrotechnic mixtures may damage your hands, eyes or face. Larger amounts can threaten arms, legs and life. The hazards are greatly reduced by using smaller amounts. Also be aware that a mixture using finer powders will generally behave MUCH more vigorously than the same mixture made with coarser ingredients. Many of these mixtures are MUCH more powerful than comparable amounts of black powder. Black powder is among the tamest of the pyrotechnician's mixtures. --*** rule completely redone 2. Many of these mixtures are corrosive, many are very toxic, some will react strongly with nearly any metal to form much more unstable compounds. Of the toxics, nearly all organic nitrates have *very* potent vasodilator (heart and circulatory system) effects. Doses for heart patients are typically in the small milligram range. Some can be absorbed through the skin. --*** rule added 3. Keep your work area clean and tidy. Dispose of any spilled chemicals immediately. Don't leave open containers of chemicals on your table, since accidental spillage or mixing may occur. Use only clean equipment. 4. If chemicals need to be ground, grind them separately, never together. Thoroughly wash and clean equipment before grinding another chemical. 5. Mixing should be done outdoors, away from flammable structures, and where ventilation is good. Chemicals should not be mixed in metal or glass containers to prevent a shrapnel hazard. Wooden containers are best, to avoid static. Always use a wooden implement for stirring. Powdered mixtures may be mixed by placing them on a sheet of paper and rolling them across the sheet by lifting the sides and corners one at a time. 6. Don't store powdered mixtures, in general. If a mixture is to be stored, keep it away from heat sources, in cardboard or plastic containers. Keep all chemicals away from children or pets. 7. Be sure all stoppers or caps, especially screw tops, are thoroughly clean. Traces of mixture caught between the cap and the container can be ignited by friction from opening or closing the container. 8. Always wear a face shield, or at least shatterproof safety glasses. Also wear a dust mask when handling powdered chemicals. Particulate matter in the lungs can cause severe respiratory problems later in life. Wear gloves and a lab apron when handling chemicals. This rule is very important. 9. Make sure there are no ignition sources near where you are working. This includes heaters, motors and stove pilot lights. Above all, DON'T SMOKE! 10. Have a source of water READILY available. A fire extinguisher is best, a bucket of water is the bare minimum. 11. Never, under any circumstances, use metal or glass casings for fireworks. Metal and glass shrapnel can travel a long way, through body parts that you'd rather they didn't. 12. Always be thoroughly familiar with the chemicals you are using. Don't just rely on the information provided with the recipe. Look for extra information - the Merck Index is very good for this, especially regarding toxicity. It can also provide pointers to journal articles about the chemical. 13. Wash up carefully after handling chemicals. Don't forget to wash your ears and your nose. 14. If a device you build fails to work, leave it alone for half an hour, then bury it. Commercial stuff can be soaked in water for 30 minutes after being left for 30, then after 24 hours cautious disassembly can be a valid learning experience. People have found "duds" from shoots that took place over a year ago, having been exposed to rain etc, which STILL functioned when fitted with fresh fuse or disposed of in a bonfire. Even after a 30 minute waiting period (minimum), initial pickup should be with a long- handled shovel. --*** above rule updated 15. Treat all chemicals and mixtures with respect. Don't drop them or handle them roughly. Treat everything as if it may be friction- or shock-sensitive. Always expect an accident and prepare accordingly, even if all these safety precautions are observed. Several people on the net have gotten stitches, lost fingers, or been severely burned. Some of them were very scrupulous in their safety precautions and had many years' safe experience with pyrotechnics. --*** rule 15 updated 7a. Nitrogen Tri-Iodide, NI3 ---------------------------- Nitrogen Tri-Iodide is a very unstable compound that decomposes explosively with the slightest provocation. It is too unstable to have any practical uses, but is often made for its novelty value. Some books describe uses for it in practical jokes etc. but in my experience it has been far too unstable for this to be a feasible idea. Reagents: Solid Iodine (I2) Ammonia solution (NH4OH) - Use only pure, clear ammonia. Other solutions, such as supermarket 'cloudy' ammonia, will not give the desired product. --*** info on ammonia added Place a few small pieces of iodine in a filter paper and filter ammonia through them. Use a small amount of ammonia and refilter it, to reduce wastage. The smaller the pieces of iodine the better the result, as more iodine will react if it has a greater surface area. You will be able to recognise the NI3 by its black colour, as opposed to the metallic purple of the iodine. Reaction: 3I + 4NH OH ---> 3NH I + NI + 4H O 2(s) 4 (aq) 4 (aq) 3(s) 2 (aq) --*** not sure of this, but it balances OK. When the NI3 decomposes it will leave brown or purple iodine stains. These are difficult to remove normally, but can be removed with sodium thiosulphate solution (photographic hypo). They will fade with time as the iodine sublimes. --*** Iodine stains fading info added Safety aspects: NI3: Despite the common misconception presented in many articles on NI3, it is NOT safe when wet. I have personally witnessed NI3 exploding while at the bottom of a 1000Ml plastic beaker full of water. NI3 can not be relied on not to decompose at any time. Even the action of air wafting past it can set it off. If you want to dispose of some NI3 once you have made it, it can be reacted safely with sodium hydroxide solution. NI3 is a potent high explosive, and should be treated with respect. Its power, instability and unpredictability require that only small batches be made. Do not make more than you can immediately use. Never attempt to store NI3. The detonation of NI3 releases iodine as a purple mist or vapour. This is toxic, so avoid breathing it. Toxicity data on NI3 is unknown, but I think it is safe to assume that eating or touching it would be a bad idea anyway. --*** NI3 safety info updated Iodine: Iodine sublimes easily at room temperature and is toxic - ingestion of 2-4g of iodine can be fatal. Make sure you are in a well-ventilated area, and avoid touching the iodine directly. Ammonia: Again, use in a well-ventilated area as ammonia is not particularly pleasant to inhale. Ammonia is corrosive, so avoid skin contact, especially if using relatively concentrated solution. If skin contact occurs, wash off with water. Don't drink it. 7b. Thermite ------------ The thermite reaction is a redox reaction that produces a lot of heat and light. In its usual configuration, temperatures can exceed 3000 degrees C, and molten iron is produced. It is therefore mainly used for welding, and by the Army in incendiary grenades. There are many possible configurations - basically it is the reaction between a reactive metal and the oxide of a less reactive metal. The most common is as follows: Aluminium powder, Al (coarse) 1 volume part Iron (III) Oxide, Fe203 1 volume part A stoichiometric mixture will provide best results. --*** line above added The powders are mixed together and ignited with a suitable fuse. Many people use magnesium ribbon - I don't recommend this, as magnesium ribbon is not all that easy to light, and quite prone to going out due to oxygen starvation. A much better fuse for thermite is a common sparkler. The mixture should be shielded with aluminium foil or similar to prevent sparks from the sparkler igniting the thermite prematurely. Reaction: 2Al + Fe O ---> Al O + 2Fe + lots of heat (s) 2 3(s) 2 3(s) (l) The mixture can be varied easily, as long as the metal oxide you are using is of a less reactive metal than the elemental one you are using, e.g. copper oxide and zinc. Adjust the ratios accordingly. Safety aspects: Reaction: Make sure you no longer need whatever you are igniting the thermite on - the reaction will melt and/or ignite just about anything. If you ignite the thermite on the ground, make sure the ground is DRY and free of flammable material. If the ground is wet a burst of steam may occur, scattering 3000 degree metal everywhere. Be careful when igniting the thermite - use adequate shielding to prevent premature ignition. Don't get close to the mixture once ignited - it has been known to spark and splatter. Don't look at the reaction directly. It produces large amounts of ultraviolet light that can damage the eyes. Use welder's goggles, 100% UV filter sunglasses or do not look at all. --*** updated - any comments on the validity of sunglasses? Aluminium: Aluminium dust in the lungs is very bad. The original Tin Man in the movie "The Wizard of Oz" had his lungs severely damaged by the aluminium dust used to colour his face. As always, wear a dust mask. Make sure the environment you are working in is dry - aluminium powder is dangerous when wet. Fine aluminium dust is pyrophoric - this means it can spontaneously ignite in air. For this reason aluminium powder with a large particle size is recommended. --*** Aluminium safety info updated Iron Oxide: This is not directly toxic, but any particulate matter in the lungs is not good. Again, the dust mask is important. 7c. Dry Ice Bombs ----------------- Dry ice bombs are devices that use pressure to burst a container, producing a loud report and limited shock effects. No chemical reaction is involved - the container, usually a plastic 2-litre soft drink bottle, is burst by the physical reaction of solid carbon dioxide, CO2, subliming into gas. As the CO2 sublimes, the pressure builds up and eventually the container ruptures. The method is very simple - some dry ice is added to the container, some water is added (about 1/3-1/4 full) and the cap is screwed on tight. Within a short time the container will burst, usually extremely loudly. The water can be omitted if a longer delay time is required. It is reported that these devices can be manufactured using liquid nitrogen instead of dry ice, and no water. This is not recommended as the delay time will be substantially shorter. --*** reversed additon - dry ice goes in before water, added LN2 variant Safety aspects: Device: NEVER use glass or metal containers! I cannot stress this enough. Dry ice bombs are extremely unpredictable as to when they will go off, and a glass or metal container is very very dangerous to both the constructor and anyone else in the vicinity. Plastic bottles are much safer because the fragments slow down quicker, and thus have a smaller danger radius around the device. Plastic fragments are still very nasty though - don't treat the device with any less caution just because it is made of plastic. There is no way to tell how long you have until the dry ice bomb explodes - it can be anywhere from a few seconds to half an hour. Never add the water or screw the cap on the container until you are at the site you want to use it and you are ready to get away. Never go near a dry ice bomb after it has been capped. If a dry ice bomb fails to go off, puncture it from long range with a slingshot, BB gun, by throwing stones at it or similar. Some indication of timing can be achieved by semi-crushing the container before capping - once the container has expanded back to its original shape it is no longer safe to be anywhere near. Don't forget that the temperature of the day and the size of the dry ice pieces will affect the delay length - don't assume that delay times will be similar between bombs. A hotter day or smaller pieces of dry ice (i.e. greater surface area) will create a shorter delay. Remember, even though no chemical reaction occurs you can still be legally charged with constructing a bomb. --*** added warning about plastic shrapnel, also instructions not to add water --*** until at the site and ready to get away, also info about temperature and --*** dry ice chunk size affecting delay length, also disposal of unexploded --*** bombs by long-range puncturing. Dry Ice: Humans will suffocate in an atmosphere with a carbon dioxide concentration of 10% or more. Use in a well-ventilated area. Dry ice typically has a temperature of about -75 degrees C, so do not allow it to come into contact with the skin, as freezer burns and frostbite will occur. Always use gloves or tongs when handling dry ice. 7d. Smoke Bombs --------------- --*** replaces ammonium chloride/potassium chlorate composition A relatively cheap and simple smoke mixture is potassium nitrate(saltpetre) and sugar. The mixture can be used in powder form, but much better results are achieved by melting the components together. The mixture should be heated slowly until it just melts - beware of excessive heating as the mixture will ignite. Keep a bucket of water next to you in case the mixture does ignite, and peform the entire operation outdoors if possible. The mixture does not have to be completely liquid, the point at which it has about the viscosity of tar or cold honey is about right. While it is semi-liquid it can be poured into cardboard or clay molds, and a fuse inserted. Once it cools and hardens it will be similar to a stick of hard candy, hence its common name of "caramel candy". --*** Anyone know a way of starting this without actually causing it to flame? --*** I would assume much more smoke would be produced if this could be done. --*** Also don't know the reaction for this one. When I did it, white smoke --*** was formed, so elemental carbon is not responsible for the smoke. Any --*** ideas, as this would help with toxicity info. As far as I know. the --*** smoke is non-toxic, apart from its particulate nature which could be --*** a problem with just about any smoke. Safety aspects: Mixture: The mixture burns very hot. Don't go near it once ignited, and don't assume that whatever the mixture is contained in or standing on will survive. Try not to breathe the smoke as fine particles in the lungs are not good for them. 7e. Basic Pyrotechnics ---------------------- (created by Gav. Minor textual clean up & expansion by dwp) Following the request for some basic info. here's a bundle I've slammed together. I hope that other people will join in with some useful suggestions for the novices amongst us. With this item being so long, I'd guarantee that there are some mistakes and ommisions,. In which case I'd appreciate someone who knows a bit about this read it through, and to write in and correct any glaringly dangerous errors. I'm not too concerned about split infinitives, however. I thought I'd start from the top with a couple of definitions, and then a quick list of the more common compounds used, their uses, and follow it up with some quick DONT's. Hope this goes some way towards helping those who are starting out...... Most of this is taken from a couple of sources, together with some of my own experience. Stars Can't find a definition for these, surprisingly. I suppose you could descrbe a star as a sample of a pyrotechnic composition which has been pressed into a block, cut into a block, rolled into a solid sphere. In this way the block or sphere of composition burns over a period of up to a few seconds, as designed). These are the bright burning objects you see ejected from rockets, roman candles, and blown out of shells. In fact they are much as they descibe themselves. They appear as bright stars when flying through the sky. Shell At it's simplest, this is a sphere of cardboard (or plastic) which contains a bursting charge (sometimes blackpowder), and stars, together with a fuse. It is blasted into the air using a mortar tube, and blackpowder as a propellant. The time the fuse burns determines the height at which the burst lights the stars, and spreads them all over the sky. The result is the *unexpected* explosion of colourful stars you see in the sky at organised displays. A shell can contain stars, stars & report, various kinds & colors of stars, etc. Sizes range from 1.5" to 36". Lance A cardboard tube (generally), in which burns a pyrotechnic composition. Often used to create pictures, write messages, etc, when several (dozen/hundred) are put together - this is referred to as lancework. Waterfall A tube, generally containing a pyrotechnic composition which burns aluminium (or sometimes other metals, such as magnesium) powder containing compositions. When several tubes are set off next to each other, placed so that they face horizontally, and ignited the effect is like a brilliant flaming white waterfall. Mine A device similar to a shell: in this case the shell is not shot into the air, but the blasting charge throws the stars into the air from where it sits. They are usually designed to throw the stars in the form of an inverted cone direction. -Gav (edited by dwp 25/5/91) There are loads of other words which I could sit here and define for you. I'll leave you to query them as they appear in the net. =========================================================================== And so to the list of chemicals.... You may recall from chemistry lessons that fire needs Fuel, Oxidiser, and heat. In pyrotechnics we need several other properties to get the fire to behave in the way we design it. We need materials with several different types of property, O-Oxidising agents F-fuels C-colouring agents E-Substances which prduce effects, sparks, whistles, etc CI-Substances to improve colours S- smoke producers B-binding agents Phlegmatisers, to reduce the sensitivity of some compositions ST- Stabilisers, to prevent unwanted reactions AR- substances which accelerate /retard combustion Aluminium F, E This is used in many compositions to produce bright white sparks, or to produce a bright white flame, when added to a composition. As a general rule, the coarser the powder, the more the *spark* effect. Ammonium perchlorate O Used as an oxidiser in rocket fuels. Using it in a composition improves the production of rich blues and reds in the flames. It is unwise to mix ammonium perchlorate (or any ammonium salt) with chlorate salts (e.g.potassium chlorate), --*** changed 'chlorate' to 'perchlorate' on above line as this may result in the production of ammonium chlorate, which is explosive. Anthracene S Used in combination with potassium perchlorate to produce black smokes. Antimony F, E The metal is commonly used in the trade as 200-300 mesh powder. It is mainly used with potassium nitrate and sulphur, to produce white fires. It is also responsible in part for the glitter effect seen in some fireworks. Antimony trisulphide F,E Used as for antimony, easier to ignite, dirtier to use, more difficult to get good effects with. Barium salts C Used to colour fires green. several are used: Barium carbonate C,ST Using the carbonate salt of barium reduces the formation of acids in firework compositions. Barium Chlorate O,C Used when deep green colours are needed. It is one of the more sensitive chemicals which are still used, best to avoid if possible, but if used it should be in combination with chemicals which will reduce its sensitivity. Barium nitrate O, C, CI Not very strong green effect. Used with aluminium powder to produce silver effects. below 1000c aluminium burns silvery-gold, characteristic of aluminium-gunpowder compositions. Above 1000c it burns silver, and may be achieved using barium nitrate. Barium oxalate C Sometimes used, generally in specialised items with magnesium. Boric acid ST Weak acid powder, used with aluminium mixtures to prevent their decomposition. Calcium carbonate ST Finds occasional use as a neutraliser. Calcium oxalate CI Used to add depth to colours produced by other metal salts Carbon black/Lampblack F A very fine form of carbon made by incompletely burning hydrocarbon fuels. Filthy stuff, but gives it's own special sparkling effect Charcoal F Probably the most common fuel in firework manufacture, it is not pure carbon, it may contain in excess of 10% hydrocarbons.Indeed, the purer carbon charcoals (eg the activated charcoal one can buy) do not necessariy give better results, and are very often worse than *lesser* grades. On a molecular level, it is comprised of layers of carbon atoms. When used in gunpowder manufacture, both sulphur and ptassium nitrate are *squeezed* between the layers, under pressure, giving an intimacy of mixing, and so a quality of gunpowder, which is very difficult to match with all but the best laboratory equipmen. Clay Very important to the firework maker. Used to make chokes (constrictions) in the card firework tubes, which increases the exit velocity of the gases, for use in fountains and rockets, for example. Copper &copper compounds C Used to add both green and blue colours to flames. Copper metal C Both the bronze, and electrolyic forms are occasionally used, but easier methods are available for the same effect. Copper acetoarsenate - paris green C Toxic, but used to produce some of the best blue colours in combination with potassium perchlorate. Basic copper carbonate C Best copper compound for use with ammonium perchlorate for production of blue colours. also used in other blue compositions. Copper oxides C Used for many years for blues, but needed mercury chloride to intensify colours. Seldom used. Copper oxychloride C Occasionally used in cheap blue compositions. Cryolite C Also known as greenland spar. this is an insoluble sodium salt. Sodium salts are used to produce yellow colours, but as sodium salts generally absorb water, this tends to be a problem. By using cryolite this problem is surmounted. Seldom used to my knowledge. Dextrin B Used as a binder, to act as an adhesive to hold a composition together. Gallic acid 3,4,5 trihydroxybenzoic acid E sometimes used to produce whistling fireworks, probably the most sensitive of all whistling fireworks, it is sensitive to both friction and impact when used with chlorates, but cannot be used with perchlorates either. There are plenty of safer alternatives. Gum resins, Gum arabic, Gum copal, Shellac, Wood resins,etc B Various adhesives used to bind firework compositions. Gunpowder This is a section to itself. At its most basic, it is a mixture of potassium nitrate (75%), charcoal (15%), and sulphur (10%), although other proportions have been used at various stages through history. (eg, in 1250 the percentages were published as 41.2, 29.4, 29.4 respectively). It can be made to an adequate standard in the garage lab, but the difference between that and the commercial grades is huge. I've not seen any that's been made by anyone *at the lab bench* that compares, although I'd love to hear from anyone whoUs got suggestions for relatively simple steps for approaching that quality. The difference is in the manufacturing process - commercially it's milled, pressed, etc. a process that's difficult to emulate at home. Gunpowder is commercially available in different grain sizes. something else to consider if you have access to it . I'll leave it for someone else / another time to take this topic further. Hexachlorobenzene CI Used as a chlorine donor in compositions, to improve the quality of colours. Traditionally, PVC seems to be preferred in european compositions. Iron Fe The metal filings have been used from the earliest times to produce sparks in fireworks. Iron will not keep well in firework compositions, and so it is generally pre-coated with an oil/ grease. One simple method is to add 1 gram of linseed oil to 16 grams of iron filings, mix, and boil off the excess oil. Linseed oil ST Used to coat metal powders in order to prevent them from oxidation, both prior to use, and in the firework composition. Polyesters are used in commercial fireworks, but linseed remains an accesible option to the amateur. Lithium carbonate C Used to colour fires red. It has no advantage over strontium salts for the same purpose. Magnesium E Used to produce brilliant white fires. Should be coated with linseed oil / polyester resin if used in a composition if not being used immediately, as it may react with other components of the mixture. The coarser magnesium turnings are often used in fountains to produce crackling sparks - an effect I'm rather fond of myself for no particular reason... Magnesium - aluminium alloys give similar effects, and are rather more stable in compositions. Magnesium carbonate Apparently useful for making perchlorate/chlorate salts free flowing - can't say I've ever used it myself, so I can't verify this. Phosphorus E Only red Phosphorus finds any real use in pyrotechnics, although I can't recall seeing any compositions with it in myself in any books less than 100 years old!! Weingart's "pyrotechnics" describes an effect using white phosphorus, which is placed in the top of a rocket just prior to launch, which gives an amazing effect of *liquid fire against a dense white smoke background* I haven't tried this myself, but I can't say I'd recommend it either. when I've used white phosphorus (which is horribly toxic, in a particularly nasty way, by the way), it has set on fire in air (as it says in the literature, but unpredictably.) Potassium benzoate E Used in whistling fireworks, in combination with potassium perchlorate. Must be very dry for this purpose, and should be less than 120 mesh. Potassium chlorate O One of the more important oxidising agents in the fireworks industry. It's sensitivity, particularly dangerous with sulphur, ammonium salts and phosphorus (it should NEVER be mixed with any of these), makes it unuseable in many potentially good compositions. Use potassium perchlorate where possible instead, unless ABSOLUTELY necessary. Potassium nitrate O One of the earliest oxidising agents, in fireworks it should pass 120 mesh, but can be usd at 60 mesh. The fine powder tends to cake if left, and has to be re-ground prior to use. Potassium perchlorate O Used in place of potassium chlorate, still an excellent oxidising agent. Mixtures with sulphur should still be avoided, though I've found some books clash on this point, I still haven't got the full story, and until someone can be definitive about this, I reckon such mixtures are best avoided. Potassium picrate E A shock sensitive compound, this is sometimes used in whistling fireworks. Relatively safe if handled with care. If ramming in a tube, don't use a lead ram (how many of us do..?), as lead picrate may be formed, which IS VERY sensitive. Sodium salts As for the corresponding potassium salts (ie sodium nitrate is equivalent to potassium nitrate, etc), but they are very seldom used, as sodium salts rapidly absorb water from the air. May be used in particularly dry environments - I gather the Egyptians used to use (and may still..) sodium nitrate in their gunpowder. Strontium salts C Used to colour flames a brilliant red. Strontium carbonate C, AR Used often for producing red colours, and as a fire retardant in gunpowder mixtures. Strontium Oxalate C, ST, AR As for strontium carbonate, generally, but suffers from greater water content. Strontium nitrate C, O Use only the anhydrous salt if possible. Gives the best red colours available. Sulphur F Together with charcoal, the backbone fuel of fireworks. Many books recommend that you do not use the common flowers of sulphur, as it contains free acid. I have no option but to, but surmount the problem (if it is real, I have never tested it, nor do I intend to for the hassle), by adding a very small quantity of potassium carbonate to the sulphur. Titanium F The coarse powder is safer than aluminium or magnesium for producing sparks, etc. Personally this is a great favourite with me. Excellent stuff if you have access to it Petroleum jelly Very occasionally used to coat metal powders, and thereby waterproof them. Zinc E Not often used. A mixture of zinc, ammonium nitrate, and ammonium chloride will ignite if a small amount of water is added to the mix. GENERAL SAFETY DO NOT mix chlorates with Sulphur or sulphides ammonium salts Phosphorus Pitch or asphalt Picric acid or picrates Fine metal powders AVOID Chlorates and oxalates (moisture problems) Chlorates with gallic acid Using potassium perchlorate with Sulphur / sulphides Phosphorus Picric acid / picrates Potassium perchlorate is hazardous when mixed with fine metal powders. Very fine metal powders are often pyrophoric. Phew.....amazing what you can get through waiting for a 3 hour reflux reaction...!!! Gav. --*** Many thanks to DWP, Christian Brechbuehler, Ken Shirriff, Robert Herndon, --*** Mike Moroney, Geoffrey Davis and others for their helpful comments, --*** corrections, additions and advice. -- ______ _____________ ______________________ ______ /\####/\ / / / / /\####/\ / \##/ \ /_______ / / _ ______ / / \##/ \ /____\/____\ / / / / \ \ / / /____\/____\ \####/\####/ / /____\ \_/ / / /_______ \####/\####/ \##/ \##/ / / / / \##/ \##/ \/____\/ /_____________________/ /____________/ \/____\/ agbrooks@teaching.cs.adelaide.edu.au