The first step to improvising a pipe bomb is to choose an appropriate explosive material as the filler. For simpler purposes match heads or gunpowder can be used though they burn rather slowly and create a lesser rupturing velocity of the pipe than other suitable materials. Permanganate with sugar half half or similarly Chlorate with sugar are easily available materials with the chlorate having a higher explosive effect than the permanganate. Aluminum (in powder form) is a potent fuel and when combined with Carbon Tetrachloride or Permanganate can produce a more dangerous explosive pipe filler. These are all of the lesser explosives which, however, are easier to acquire.
A more complicated scenario would involve the use of TNT or plastic explosives as filler which also increases the risk factors involved. The lesser powders are usually ground fine to accelerate their burning rate.
Choosing A Fuse
Military detonation cord is best to use as a fuse otherwise cannon or fireworks fuses can be used, or if available dynamite fuse.
To make a completely improvised fuse masking tape sticky side up can be placed on a surface and sprinkled with ground gunpowder, the powder will stick to the tape. It will make a fuse, although less reliable than others.
Option # 1 – Buy some fireworks sparklers. Read the box, the best ones work that have magnesium in them.
Option # 2 – Make your own sparkler for a fuse.
Option # 3 – This is dangerous, and not recommended: Another method is twine or heavy string. Simply melt some candle wax, dip the string in the wax, then lightly sprinkle gun powder on the wax before it cools.
Optional Detonation Devices:
A properly low voltage switch gate silicon controller rectifier or thyristor (any of several semiconductor devices that act as switches, rectifiers, or voltage regulators) will take the low voltage from a kitchen timer speaker line or cell phone vibrator or ringer and switch on a larger usable power supply from a battery or AC power, if the audio circuit is so low that it won't flip the SCR gate add an amplifier transistor. This is perfect for setting off timed tear gas during an event, or a phone or pager controlled smoke bombs to cover a retreat.
An altitude switch can easily be made with a can, tape, a plastic bag, wire, and two strips of metal. Securely tape and seal the plastic bag into the can with half of the air pushed out. Place one strip as a bridge on the top of the can, the other strip like a lever that the expanding bag can push across to touch the bridge strip. When the altitude gets high enough (a few thousand feet) the circuit will close and current can flow. A fun thing to do is put this onto a logging truck heading into the mountains that will ignite a string of firecrackers.
The expansion of dry beans in water can also be used as a timer, you need a clean unpainted metal disk like a can lid, two shiny nails and a straight walled plastic container. As the seeds or beans expand the metal disk will be pushed up against the nails which completes the circuit. Seal the container with tape unless air transport is expected.
All timers must be tested with the operational battery and a buzzer, or light-bulb in place of its ignite(r) or blasting cap several times. Always test the circuit to be sure that it is off before connecting the electrically activating the timer. A double activation circuit if there is room doubles the chance of success.
Perhaps the most widely used homemade concussion bombs are those made out of pipe. Perfected by George Metesky, the renown New York Mad Bomber, they are deadly, relatively safe, easy to assemble, and small enough to transport in your pocket. You want a standard steel pipe (two inches in diameter is a good size) that is threaded on both ends so you can cap it. The length you use depends on how big an explosion is desired. Sizes between 3-10 inches in length have been successfully employed. The basic idea to remember is that a bomb is simply a hot fire burning very rapidly in a tightly confined space. The rapidly expanding gases burst against the walls of the bomb. If they are trapped in a tightly sealed iron pipe, when they finally break out, they do so with incredible force. If the bomb itself is placed in a somewhat enclosed area like a ventilation shaft, doorway or alleyway, it will in turn convert this larger area into a "bomb" and increase the over-all explosion immensely.
You will need:
Obtain the Pipe, Materials, and Equipment.
-Needed is approximately a 2 inch diameter pipe 6 inches long with two threaded ends and two threaded pipe end caps.
-Teflon Pipe Tape.
-Plastic air tight zip lock freezer bags.
-Box wooden matches.
-Electric Drill with drill bit.
-Tube of Liquid Nail Glue.
-Bag of Cotton Balls.
-Fuse (see below).
-Detonator (see below).
-Explosive Materials (see below).
-Gun (black) Powder (this can be obtained from a local gun shop)(other types of explosives can be used, see below).
-12 inch Ruler.
-Black Magic Marker.
-Fuse (cannon fuse or firecracker fuse works best)
IMPOTANT: Test any fuse before using. Cannon fuse can usually be obtained from a local gun shop. If you make your own fuse, it will not be as reliable.
One thing that any bomber should have learned from The Unabomber's (Ted Kaczynski) bombs is, add some shrapnel.
This can be tiny nails, small screws, etc. For higher velocity, use small ball bearings or shotgun shot.
The shrapnel (nails or other sharp objects) can be part of the pipe bomb in two different ways-
(1) Mix the shrapnel with the explosive inside the pipe bomb.
(2) Duct Tape the shrapnel to the outside (outer wall) of the pipe bomb.
Using shrapnel will severely increase the damage you do while using this pipe bomb.
Important Safety Tip: Always prepare the pipe in advance and fill the explosive or powder into a sealed plastic bag, this reduces the possibility of a friction explosion.
Important Safety Tip: Never coat the cotton ball with liquid chemicals such as diesel fuel, alcohol, gasoline, etc. These types of chemicals expand in weather and will cause the pipe bomb to prematurely explode.
(How to) Make Pipe bombs
First pipe bombs made from soft metal.
1.) Flatten one end of a copper or aluminum pipe carefully, making sure not to tear or rip the piping. Then, the flat end of the pipe should be folded over at least once, if this does not rip the pipe.
2.) A fuse hole should be drilled in the pipe near the now closed end
3.) and the fuse should be inserted.
4.) Next, partially fill the casing with a low order explosive, and pack it with a large wad of tissue paper.
5.) Flatten and fold the other end of the pipe with a pair of pliers. Do this slowly, since the process of folding and bending metal gives off heat, which could set off the explosive.
Preparing the pipe.
First using the ruler and magic marker, mark one inch lines on the outside of the pipe for measurement purposes.
This is done upside down from use.
Using one of the pipe caps, drill a hole in the center. This should be slightly larger than the fuse or detonator.
Insert the fuse, it needs to be long enough to go into the pipe, about two inches.
Using some hot candle wax gently drop wax on both sides of the hole in the cap to insure closer.
Take the pipe and apply the teflon tape to the top of the pipe.
Using the alcohol wipe both of the pipe cap threads clean, let dry.
Take the pipe cap and screw it onto the pipe tightly.
Now cut the ends of the wooden matches off.
Drop the match heads into the pipe.
Now pack about inch of compressed cotton into the pipe. Be careful not to damage the fuse and make sure it extends past the cotton. Use a broom stick to compact the cotton but remember there are match heads so don't pound or scrap it around, pack it tight but not to tight.
Now cut a small hole in the bottom of the plastic bag gently load the bag into the pipe making sure the fuse goes inside the bag.
Pull the bag up and over the open end of the pipe.
Now fill the bag with the gun powder. Remember you still need to close the bag and get it totally inside the pipe so the end will close.
Once you think you have the right amount of powder, seal the zip lock bag and stuff it inside the pipe.
Note: If you are using shrapnel you load that alternating with the gun powder.
Once the bag is inside and you know the cap will go on without compressing the bag, fill the empty areas, if any with cotton, do not pack.
Wipe the inner and outer threads of the pipe with a damp washcloth (do not get any water inside the pipe).
To be safe, clean the outside of the pipe threads with alcohol and let thoroughly dry.
Now apply the teflon tape to the threads of the pipe.
Gently screw the bottom cap on.
Finally using the Liquid Nail Glue run a bead of glue around the pipe caps and pipe on both ends. This prevents the pipe caps from coming lose.