PrimoPyro1990 .... Detonators .... DISCLAIMER: The following file contains information of harmful or illegal nature. Neither the BBS or author providing this information can be considered responsible for the use of this file. The person using this knowledge is solely responsible for it's use or misuse. This file is intended to educate only. Modern high explosives require a shock to explode. The detonator provides this shock. Detonators are powerful enough to take off your fingers completely and shatter your hand so care must be used in the making and handling of them. The standard nonelectric detonator consists of a brass tube about 1/4" I.D. with thin walls and a length of about 2 1/2" to 3". This tube is sealed at one end and open at the other. The tube contains two explosives, one layer upon the other. The bottom layer is called the base charge and is usually an insensitive high explosive. The top layer is the initiating charge and is a sensitive explosive. At one time the usual blasting cap contained 2 gms. of mercury fulminate and was called a #8 cap. A #6 cap contained 1 gm. of fulminate. Other caps with less strength were numbered lower. Since fulminate is a sensitive explosive, detonators with less of it were safer to handle. To use this type of detonator, a fuse is inserted into the tube and pushed against the fulminate. The tube is then crimped around a blasting fuse with a special tool for this purpose. An electric detonator consists of the same detonator as above but now an electric match is inserted in place of the fuse and sealed in with a water- proof seal. The wires for the detonator are twisted together or somehow shorted together to keep stray radio signals from causing premature deton- ation. If the wires are not twisted together, one lead may act as an antenna while the other acts as a ground. If the wires intercept a radio signal, the induced current may be enough to heat up the detonator's filament and cause an explosion. Old detonators were made with a spark gap instead of a filament and were set off when a high voltage spark jumped the gap. This type of det- onator can be set off by static electricity generated by walking across a carpet. Another type of detonator is the exploding brigewire detonator. This uses no primary explosive such as fulminate. Instead, a small diameter wire is used in place of a filament. A capacitor is charged up to say 300 v. and 200 uFD. The capacitor is then discharged through the detonator causing the bridge- wire to explode. This microexplosion is enough to cause the initiaton of the secondary explosive. If a battery is connected to the detonator, the bridge- wire burns through without detonating the explosive. These detonators are very safe to handle and use but the firing circuit is complex. Still another type of detonator is a percussion detonator. This is a mechan- ically initiated device. It consists of a nonelectric detonator with a primer sealed in one end. When a firing pin hits the primer the resulting flash fires the detonator. Sometimes a stab detonator is used. This is very much like the percussion detonator but instead of the firing pin, a needle is used to pierce the sensitive end of the cap. The most modern detonators include a built in electronic timer that causes detonation at some precise time after the detonation pulse is received. This delay is programmable and is used to tailor the explosion to suit individual needs. The explosive is also configured as a small shaped charge to cause a more perfect detonation of the main charge. Primary Explosives Used in Detonators Primary explosives are chemicals that do not burn but explode directly from a flame or spark. They are also usually very sensitive to shock. Mercury fulminate can be found in toy paper caps for use in a cap pistol. The quantity in a paper cap is about 1/10 of a grain. There are 15.4 grains in a gram so approximately 154 of them contain one gram. If you have heard one cap exploding, imagine 154 of them going at once. The following are manufacturing processes for small laboratory amounts of primary explosives. Follow safety rules if you decide to manufacture them. Mercury Fulminate: This is one of the oldest explosives used for making deto- nators. It is one of the easiest explosives to make. In a glass container put 40 ml. of 90% nitric acid. If you have red fuming nitric acid, put in 10 ml. of water then add 30 ml. of acid one drop at a time until all the acid is added. Water should never be added to acid. The reaction can cause splattering of the acid. Acid to water is what you oughta. Water to acid is not very placid. Now, add 5 gms. of mercury metal. As the metal dissolves in the acid, some red fumes of nitric oxides may be released. Avoid breathing them. Allow the mixture to stand until the mercury is dissolved. You may want to stir the acid to help the mercury dissolve. The mercury may take some time to dissolve so have patience. When the metal is dissolved, add the acid to 75 ml. of warm 90% ethyl alcohol.in a 500 ml. glass container. In a few minutes a reaction will start. The mixture will start bubbling and frothing so the reaction must take place in a large container. White fumes will start coming out of the reaction and must not be inhaled. The white fumes will give way to red fumes then change back to white again. A precipitate will be seen to form in the liquid. This is mercury fulminate. When the reaction stops bubbling, pour the liquid into about 12 oz. of water. Wash the precipitate out of the reaction container and into the water. Filter the fulminate out of the water and wash it with a few ounces of ethyl alcohol and a final wash of a few ounces of distilled water. The fulminate should be a grayish to a white powder. It is best stored under water until use. Mercury fulminate can be exploded by a 4 cm. drop of a 1 kilo weight. It will become "dead pressed" if subjected to pressures of 25,000 - 30,000 psi and will no longer explode but just burn. DDNP: Diazodinitrophenol is a greenish yellow to a brown crystal and is superior to fulminate as a detonating agent. To make it, dissolve 1 gm. of sodium hydroxide in 65 mls. of distilled water then add 6 gms of picric acid to the lye solution. In another container put 10 ml. of distilled water and add 5 gms. of sulfur to the water. Now add 5 gms. of sodium hydoxide to the sulfur/water. Boil this mixture until it turns bright red. Let the solution cool off. Add the sulfur/lye to picric acid solution in four portions letting the picric solution cool down in between additions. Stir the solution while adding the sulfur/lye. Let the mixture cool off then filter out the red particles. Dissolve the red particles in 130 mls. of boiling water. Filter the solution and discard any precipitate, save the solution. Add 80% sulfuric acid to the solution drop by drop until it turns an orange- brown color then add 15 mls. more sulfuric acid. Let the solution cool down to room temperature. Dissolve 3.75 gms of sodium nitrite (not nitrate) in 150 mls. of distilled water. Add the nitrite solution to the orange-brown solu- tion all at once while stirring. Let the solution stand for 10 - 15 mins. The solution should be a brown color. Filter out the particles of DDNP and wash them with 100 mls. of distilled ice water. Store the DDNP under a small amount of water until use. Lead Picrate: When picric acid reacts with a metal a picrate is formed. The heavier the metal the more sensitive an explosive is formed. Lead picrate is a useful explosive for making improvised detonators. The picrate will explode from heat, sparks, or shock. In a small glass container put 5 gms. of picric acid. Add to this 25 mls. of ethyl alcohol and stir the two to make a paste. Add 5 gms. of lead monoxide to the paste and gently stir the mixture. This is now an explosive. Store the paste still wet with alcohol in a sealed glass container until needed. Lead Azide: Lead azide is probably the most commonly used explosive in modern detonators. It is not as shock sensitive as mercury fulminate. It must be precipitated in the presence of dextrin to keep the particles of azide small. Failure to do this will result in an explosion as the large crystals of azide explode from inner stresses. Dissolve 17 gms. of lead nitrate and 1.5 gms. of dextrin in 250 ml. of distilled water. Adjust the pH of the solution to 5.4 with sodium hydroxide then heat the water to 70 deg. C. While stirring the solution strongly add a solution of 6.5 gms. of sodium azide and 1.5 gms of sodium hydroxide in 250 mls. of distilled water. Continue stirring for 5 min. Filter out the lead azide and wash with about 500 mls. of distilled water. Store the lead azide under water until needed. Secondary Explosives Used in Detonators These explosives are relatively insensitive and are used to strengthen the explosion of the detonator. These explosives are classified as a high explosive. Picric Acid: This process was taught by the CIA for their improvised explo- sives course. It produces an explosive from aspirin. Crush 20, 5 grain aspirin tablets and add 1 tsp. of water to it to make a paste. Stir in 1/2 cup of ethyl alcohol to the aspirin paste and then filter the solution to remove any solid particles. Evaporate the alcohol and recover the crystals that are left. Pour 1/3 cup of concentrated sulfuric acid into a large jar and add the crystals from the alcohol solution. Heat the acid in a simmering hot water bath for 15 mins. The acid should turn a reddish color. Now add 15 gms. of potassium nitrate to the acid 5 gms. at a time while stirring. Let the acid cool to room temperature then pour the acid slowly into 1 1/2 cups of water and let it cool down again. Filter off the particles of picric acid and wash them with 1 cup of ice water. Dry these crystals before using them. Picric acid is a very strong dye. Contact with it will stain just about anything. Picric acid also reacts with metal to form picrate salts that are a hazard. Any metal in contact with picric acid should be coated with an acid proof paint or an epoxy coat. Guncotton: This is not very commonly used especially for detonators but for improvised work it is perfect. Make an acid mixture composed of 3 parts by volume concentrated nitric acid and 1 part concentrated sulfuric acid. Take a small piece of cotton and quickly push it under the acid with a glass rod. Leave it under the acid for 5 mins. then pull out the cotton and squeeze out the excess acid. Quickly push it under water to wash out any acid rem- aining in the cotton. Now wash the cotton in fresh water containing a few percent of sodium bicarbonate. Pull the cotton apart to help the water get to all the fibers. Now wash the cotton in warm water for 15 mins. If you want to remove all the acid trapped in the fibers, expose the cotton to strong sunlight for one or two days then wash it in a 3% sodium bicarbonate solution for 1/2 hour followed by a wash with distilled water. If all this washing sounds redundant it isn't. The acid gets trapped inside the fibers of the cotton and causes the explosive to deteriorate after a while. Guncotton is very spark sensitive and should be stored wet with water until used. Cyclonite: Also known as cyclotrimethylenetrinitramine or simply RDX, this is one of the most powerful explosives known. It is not too sensitive but as with all explosives handle with care and common sense. RDX is produced by nitrating hexamethylenetetramine (HMT). HMT is used to make fuel sticks for use in small survival or camping stoves. It can be made by treating an ammonia solution with formaldehyde and evaporating the liquid to obtain the HMT. If you have problems getting formaldehyde, check out a boating supply or paint store for resorcinal glue. It is a two part glue, one part which is paraformaldehyde. This is a powder and is simply a polymer of formaldehyde which you can use. Cool 60 gms of 100% nitric acid to 0 deg. C. and add 5 gms. of HMT to the acid in several small portions while not letting the temperature go above 30 deg. C. When all the HMT is added, let the acid cool down to 0 deg. C. then let it stand for 20 mins. At that time, dump the acid into two pints of cold water. The RDX will precipitate and should be filtered out and then washed with water until it is free of acid. The RDX can be stored dry in a cool place until needed. Making a Detonator Obtain a small brass tube with a 1/4" I.D. and seal one end with an epoxy plug. The length of the tube should be about 3". Weigh out 1 gm. of one of the secondary explosives and press it into the bottom of the tube .25 gm. at a time. Do not subject the explosive to shock but press it in the tube with a wooden dowel to avoid all sparks. Press a small paper disk down onto the explosive. Weigh out .75 gm. of a primary explosive and press this into the tube .25 gm. at a time. If you are using an electric ignitor, insert it into the tube up against the primary explosive and seal the ignitor into the tube with a little epoxy. These detonators are much more powerful than the standard commercial or military detonator and should be able to detonate any explosive you are using. An electric ignitor for a detonator can be made as follows. Take a small (3/8" long) section of tube that you are using for the detonator and coat the inside with silicone or wax. Put the tube onto a piece of wax- paper. Fold a length of 27 ga. solid wire into a hairpin loop and hold the loop in the tube up against the waxpaper. Put a few drops of 5 min. epoxy in the tube and let it harden. Now fill up the rest of the tube with the epoxy. Peel the waxpaper away from the tube and push the epoxy plug out of the tube. Take a file and file the end of the plug until the wire diameter at the loop is reduced to 1/4 the original diameter. Mix a small amount of black powder with dextrin and water to make a paste then coat the wire loop. When 6 - 12 volts are connected to the wire leads the black powder will flash. This can be sealed into a detonator if you want to make it an electric detonator. You can take a shotgun primer and make up a brass collar to hold it tightly in a detonator tube. A little bit of epoxy will seal it into the end of the detonator if you want to make a percussion initiated detonator. Be careful when making, storing, and using detonators. Too many accidents have been attributed to the careless handling of them. *** Kilroy was here ***