Post by Anders Hoveland on Feb 3, 2011 16:03:12 GMT -8
This is an improvised bomb which is not very effective at damaging anything, but nevertheless makes an impressive explosion. While it would be very ineffective as a weapon, it is potentially very hazardous. The bomb utilizes fairly easy to obtain materials, but some careful thought and effort must be done for the construction and assembly.
When the pressurized gas mixture detonates, it expands to around 20 times its original volume. The explosion is extremely loud and could easily cause ear damage. The bottle can shatter thick clay pots if placed inside, and can blast a small hole if placed against a light framed hollow door.
Unlike typical gas bottle bombs, where a gas builds up, eventually causing the bottle to burst, this particular device actually involves a detonation of the pressurized gas mixture.
Hydrogen peroxide, of 10-20% concentration, is placed into a 2-liter plastic soda bottle. The bottle should be filled only a fifth to a fourth full, leaving plenty of room for gas above. Soda bottles can typically handle pressures 4-5 times greater than normal atmospheric pressure.
A propane canister fitted with a valve is used to introduce propane gas into the bottle. About 12 seconds of full flow should be sufficient. Propane is heavier than air, but can still escape out of the open bottle. A small quantity of catalyst is quickly added and the cap immediately tightly fitted on. After the cap has been placed on, immediately run away from the bottle.
The catalyst can be steel wool or manganese dioxide (the purplish black material found inside alkaline batteries). Only a small amount should be added, less than half a spoon full.
The bottle will slowly build up pressure. When the concave bottom of the bottle begins to pop out, the gas mixture should be detonated. Waiting for more pressure to build up could cause the bottle to simply burst. 1-Liter bottles seem to be able to handle more pressure than 2-Liter bottles. For the smaller bottle, the bottle typically will not burst for at least two minutes after the bottom pops out (this causes the bottle to tip over). For the larger 2-Liter bottle, the lid blows off the top (often breaking off with the screw top) much sooner, sometimes even before the concave bottom of the bottle has fully popped out.
The gas mixture can be detonated by two optional methods.
One method is to simply ignite a mixture of sawdust held together with a lesser portion of petroleum jelly that is placed over the bottle which has been turned on its side. This has several disadvantages. The other method is to insert and tape two cutouts of aluminum foil against the inside of the bottle. This is difficult, but not impossible. Each plate should have a surface area of at least
8 cubic cm, and the two plates should have a gap of exactly 1-2mm
between them. The insertion can be accomplished by placing tape around the 3 of the edges of the foil, cutting the tape to leave a 1cm perimeter of tape around the foil, then using tweezers to insert and place the foil plate against the inside of the bottle.
Two more plates are placed against the inside foil plates, but on the outside of the bottle. There should, however, be at least 2cm separating the outside foil plates. Both of these outside foil plates are connected to wires, which are connected to a high voltage transformer. The voltage of the transformer must be at least 6kV, but preferably more than 9kV. When the transformer is activated, the electric current can go through the plastic bottle and create a tiny spark gap that ignites the gases inside the bottle. The plastic layer acts as two capacitors for the foil layers. A recommended transformer is a 9kV portable neon transformer (actually a flyback circuit) which runs on a 12v battery. One should have some familiarity with electronics to utilize this latter method, which is more advantageous over the first. Using electric ignition can allow optimal timing of the detonation. One note about the wires, use wire lengths of at least 6 meters, and if the wires are not designed for high voltage, maintain a separation between the two wires, otherwise if the wires come into contact with each other, the electric current could arc through the insulation. It is recommended to take cover behind a protective barrier and wear safety goggles if directly observing the explosion. Unfortunately the high voltage has significant loss along lengths of ordinary wire. If a higher current (over 20mA) transformer is used, 14 meters would be a much more preferable safety distance. Depending on the transformer, a larger 12v lead acid battery may be required. Unless you are very familiar with the dangers and precautions that must be taken handling high voltage, it is strongly recommended that a large neon sign transformer (that plugs into an electrical outlet) not be used.
There are small transformers that plug into outlets (one of which I purchased for only 15 Euros online, it had the brand name "Fransformer"), but extreme caution should still be taken. Use an electric switch to turn on the tranformer. Under no conditions should the transformer be plugged in, and certainly one should completely avoid the high voltage side of the wiring when the transformer is on. Do not handle the transformer or wires carrying the high voltage, the current can easily arc through insulated gloves!
When the pressurized gas mixture detonates, it expands to around 20 times its original volume. The explosion is extremely loud and could easily cause ear damage. The bottle can shatter thick clay pots if placed inside, and can blast a small hole if placed against a light framed hollow door.
Unlike typical gas bottle bombs, where a gas builds up, eventually causing the bottle to burst, this particular device actually involves a detonation of the pressurized gas mixture.
Hydrogen peroxide, of 10-20% concentration, is placed into a 2-liter plastic soda bottle. The bottle should be filled only a fifth to a fourth full, leaving plenty of room for gas above. Soda bottles can typically handle pressures 4-5 times greater than normal atmospheric pressure.
A propane canister fitted with a valve is used to introduce propane gas into the bottle. About 12 seconds of full flow should be sufficient. Propane is heavier than air, but can still escape out of the open bottle. A small quantity of catalyst is quickly added and the cap immediately tightly fitted on. After the cap has been placed on, immediately run away from the bottle.
The catalyst can be steel wool or manganese dioxide (the purplish black material found inside alkaline batteries). Only a small amount should be added, less than half a spoon full.
The bottle will slowly build up pressure. When the concave bottom of the bottle begins to pop out, the gas mixture should be detonated. Waiting for more pressure to build up could cause the bottle to simply burst. 1-Liter bottles seem to be able to handle more pressure than 2-Liter bottles. For the smaller bottle, the bottle typically will not burst for at least two minutes after the bottom pops out (this causes the bottle to tip over). For the larger 2-Liter bottle, the lid blows off the top (often breaking off with the screw top) much sooner, sometimes even before the concave bottom of the bottle has fully popped out.
The gas mixture can be detonated by two optional methods.
One method is to simply ignite a mixture of sawdust held together with a lesser portion of petroleum jelly that is placed over the bottle which has been turned on its side. This has several disadvantages. The other method is to insert and tape two cutouts of aluminum foil against the inside of the bottle. This is difficult, but not impossible. Each plate should have a surface area of at least
8 cubic cm, and the two plates should have a gap of exactly 1-2mm
between them. The insertion can be accomplished by placing tape around the 3 of the edges of the foil, cutting the tape to leave a 1cm perimeter of tape around the foil, then using tweezers to insert and place the foil plate against the inside of the bottle.
Two more plates are placed against the inside foil plates, but on the outside of the bottle. There should, however, be at least 2cm separating the outside foil plates. Both of these outside foil plates are connected to wires, which are connected to a high voltage transformer. The voltage of the transformer must be at least 6kV, but preferably more than 9kV. When the transformer is activated, the electric current can go through the plastic bottle and create a tiny spark gap that ignites the gases inside the bottle. The plastic layer acts as two capacitors for the foil layers. A recommended transformer is a 9kV portable neon transformer (actually a flyback circuit) which runs on a 12v battery. One should have some familiarity with electronics to utilize this latter method, which is more advantageous over the first. Using electric ignition can allow optimal timing of the detonation. One note about the wires, use wire lengths of at least 6 meters, and if the wires are not designed for high voltage, maintain a separation between the two wires, otherwise if the wires come into contact with each other, the electric current could arc through the insulation. It is recommended to take cover behind a protective barrier and wear safety goggles if directly observing the explosion. Unfortunately the high voltage has significant loss along lengths of ordinary wire. If a higher current (over 20mA) transformer is used, 14 meters would be a much more preferable safety distance. Depending on the transformer, a larger 12v lead acid battery may be required. Unless you are very familiar with the dangers and precautions that must be taken handling high voltage, it is strongly recommended that a large neon sign transformer (that plugs into an electrical outlet) not be used.
There are small transformers that plug into outlets (one of which I purchased for only 15 Euros online, it had the brand name "Fransformer"), but extreme caution should still be taken. Use an electric switch to turn on the tranformer. Under no conditions should the transformer be plugged in, and certainly one should completely avoid the high voltage side of the wiring when the transformer is on. Do not handle the transformer or wires carrying the high voltage, the current can easily arc through insulated gloves!