Remote detonation & improvised blasting cap
I see alot of threads with great recipies for explosive mixtures, thermite, etc, but very little discussion of detonation techniques. I would like to kick off this thread with a basic homemade electric blasting cap & remote detonator i made the other day. It is useful for detonating most explosives such as ANFO or gunpowder. Thermite would require some magnesium strips as an intermediate booster to achieve the proper ignition temperature. So here it is:
Flashlight lightbulb (non-LED), electric wire, ground up match-heads, tape, pre-paid cell phone with vibrating electric motor, 9V battery. wire solder
1. tape (or soldier) wires to terminals of light bulb.
2. drill a hole in the glass of the light bulb, fill bulb with ground match-heads.
3. open back of cell phone and locate the motor used for vibration (notice the lop-sided metal shaft that causes vibration when it spins).
4. secure wires near spining cam on motor so when it spins it completes circuit with light bulb.
5. Insert bulb into main charge
6. attach 9V battery to this OPEN circuit. (do yourself a favor and make the wires long enough that a pre-mature detonation would not kill you when you hook up the battery)
7. Call cell phone (i know you made sure it was on vibrate...)
Sorry for the length, but this shit really works. I know this design can be improved, so please let me know what you think...
September 2nd, 2009
You can go ahead and link us to the rotten eggs posts or the instructables that showed you how to do that now... The reason being, the original posters of that setup on both sites did a much better job explaining with pictures than you did explaining with words. And a light bulb full of match heads will NOT detonate ANFO. Sorry, try again.
how will match heads detonate ANFO, don't you need a supersonic explosion for that???
Match heads will more than likely not light ANFO. I believe that barium nitrate was recommended for such purposes. And no, a supersonic explosion is not required in the least.
Sorry about the ANFO mistake - I admit i have never used it before. Thank you DoG MikkyW, for your constructive criticism.
CP1074, I am not pretending to be the inventor of this device, nor am i trying to compete with websites with expertise and presentation that far exceeds my own. I am however, trying to have a conversation about detonators so I can learn from other members.
You (and the others) have already shared your knowlege of the detonation of ANFO with me, something I (perhaps foolishly) missed on the other websites. That is the reason I have brought my rough description of this device into this forum.
Please share your comments about possible improvements to the circuit (i am trying to substitute a relay instead of the electric motor but without much success)
I think you can get a decent amount of heat if you go to walmart and buy a model rocket set. They come with a little black box with a button that you press to make the metal tips on the wires get really hot(for me they turn red).
true that... my primary concern here is how to close the circuit (connect the battery) using a cell phone call. your method would work equally well as a substitute for the lightbulb cap, but the remote controlled switch remains an issue. the spinning motor switch is a little scary in my opinion...
I tried hooking up a switch to the phones circuits for the ringer, vibrator motor, speaker, etc. I can't seem to find the propper parts. Ideally, this would allow the cell phone to me used as either a timed detonator (by using the alarm clock) or a remote detonator (by calling the phone). I suspect i'd need to find the specs on the voltage for the motor and ringer circuits and find compatible relays to solder in place.
OK... This is all based in theory as I currently have not tested this fully nor do I have a spare phone to test with.
With my current phone, if I have the wired headphone plugged in and the phone set to silent or vibrate, when I call the phone the headphone makes a static noise. I tested this with a multimeter and have found that the jack produces no amperage or voltage at the speaker leads when this occurs. It does however create continuity across the two wires.
In theory, an e-match that can be detonated with either a 9 volt battery or a 4 pack of AA's could be wired to a circuit that is fired by a small relay wired across this monoplug lead coming out of the phone. A small watch battery can be used to trigger the relay with the + lead going from the battery to the relay and the - lead going from the battery to the jack (normal open) then from the other side of the jack to the - on the trigger side of the relay. When you call the phone this closes the mono lead creating continuity allowing the watch battery to close the relay which in turn allows the battery pack to fire your e-match. Again, this is theory at the moment as I have not tested it. I am unsure of the resistance across the mono jack on the phone and whther it will allow the watch battery to close the relay.
I'm hoping to test this soon.
Great idea. I'll give this a shot as well. I don't get the static on my headset when I call it, but that could just be the individual headset and the circuit may still be closed. Let me know if you test it successfully.
I did a quick google search and found the resistance across a 2.5mm jack is about 3 kohms, a 3.5 mm jack is about 50 mohms. Then I found an ipod headset (entire circuit) has a resistance of 8 ohms... so values are all over the place. but maybe it give us a range to work with & the type(s) of relays to try.
Last edited by runn3r88; September 5th, 2009 at 10:33 AM.
Reason: found new information
How to make an ANFO primary detonation cap:
Get any kind of oxidiser you can find, hydrogen peroxide or nitrous oxide solution, sodium chlorate or potassium nitrate, WHATEVER
on a really hot day go onto the baking street and find the dryest, whitest dogshit stuck to the pavement
crumble your white dogshit in a pestle and mortar or coffee grinder, and mix accordingly
65%+ oxidiser with white dogshit, and a sprinkle of caster sugar should add some extra nice flavour
Knead with flour and custard powder until a thick paste then microwave for 6 minuites and you have both a delicious desert AND a powerful primary explosive
(no gaurentees, i made this using my chemical logic! Somebody is yet to test this for me!!!)