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I've seen a bunch of tutorials on creating a fireworks igniter using, a resistor or a piece of copper wire and a 9 - 12 v battery. Basically you the resistance from the small piece of copper or 1 ohm resistor get so hot it triggers a match. The professional ones use nicrome wire. I'm interested in trying this out, and I have an 18V drill battery, alligator clips, and thin piece of copper wire. I measured the resistance of the copper wire at about 1 ohm.

Will closing the circuit for a small amount of time damage the battery? Can the current from the drill battery melt the copper? Would another conductor that is not as good a conductor create more heat with less current?

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    \$\begingroup\$ Why not use some model rocket igniters they're essentially what you're talking about estesrockets.com/rockets/engines/flight-supplies/… Also don't build fireworks at home :) \$\endgroup\$ – Some Hardware Guy Jul 2 '15 at 15:19
  • \$\begingroup\$ battery specs needed. 18V across 1ohm means 18A, quite a lot of juice but a good drill battery should be able to deliver that. \$\endgroup\$ – Vladimir Cravero Jul 2 '15 at 15:20
  • \$\begingroup\$ @SomeHardwareGuy because I want to be able to re-use the igniter, and use regular matches ... also I want to try and get this working for tonight \$\endgroup\$ – user379468 Jul 2 '15 at 15:29
  • \$\begingroup\$ As a kid I used to use steel wool fibers for similiar things which should be OK for a match if you just need sparks. Single use but cheap and as Vladimir said your wire would need 18A which would probably fry your alligator leads assuming you're talking about small ones because it'd take a while for something reusable to get hot enough to ignite anything. \$\endgroup\$ – PeterJ Jul 2 '15 at 15:42
  • \$\begingroup\$ How about this .... found a small 6W bulb ( tungston filament ) if I manage to smash the bulb without destroying the filament, do you think it would get hot enough to light a match? I realize it's only pulling about half an amp \$\endgroup\$ – user379468 Jul 2 '15 at 17:00
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You really should visit one of the excellent fireworks forums that are available. They have detailed instructions for making your own electric matches.

Skylighter is an excellent site run by professionals. This link takes you to their page for making your own e-matches.

It's been a long while since I read the procedure but I recall enough to give you some guidelines. But you should really go learn from the experts.

In general, home-made electric matches are made from little slivers of double-sided PCB material. You solder your lead wires (solid-core zip-cord) to each side of the sliver.

Then wrap very thin nichrome wire several times around the sliver, making sure to leave space between the turns. Use solder to hold the wire in place. The solder doesn't adhere to the nichrome wire but a sufficiently-good electrical connection is made that these igniters are reliable.

Then dip the e-match into liquid pryogen and allow to dry.

The nichrome wire used is hair-thin and has a resistance of many ohms per foot. But the actual distance of resistance is only the thickness of the PCB material. In addition, there are many such bridges all in parallel - two resistive bridges per wrap of wire on the PCB sliver.

You should wind up with a resistance around 2 Ohms. With a 12V battery, that's about 6 Amps of current. The match will ignite in a few milliseconds.

The professional sites that have this information will have the formula for the pyrogen. It's not complicated and it's not particularly dangerous so long as it is handled with care. But you really don't want to accidentally ignite a pot of the stuff.

Also note that the pyrogen isn't particularly flammable while it is wet. Only after it drys.

The commercial electric matches that I use have a lacquer coating on top of the pyrogen. This reduces the chance of friction causing accidental ignition and also increases the physical stability of the e-match.

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  • \$\begingroup\$ The only part I don't understand is why the electric part of the match needs to be consumable ... seems to me that the nicrom part can / should be re - usable and the part with the phosphorus ( match ) would be consumable \$\endgroup\$ – user379468 Jul 4 '15 at 15:50
  • \$\begingroup\$ Mostly because of the flame damage that occurs when the match ignites. I suppose that it might be possible to clean up the PCB material so that you can solder to it again. But, for the most part, e-matches are considered to be a "one-time-use" consumable item. \$\endgroup\$ – Dwayne Reid Jul 4 '15 at 19:44
  • \$\begingroup\$ Commercial e-matches are pretty darned inexpensive these days. But where I live (Canada), you must be trained and licensed before you are allowed to posses or purchase them. You must also be able to show that you can store them safely. \$\endgroup\$ – Dwayne Reid Jul 4 '15 at 19:47
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You want Nichrome wire. This is an alloy specifically designed to generate heat though high resistance. It is rated in ohms per foot (the linked wire is about 1.5 ohms/ft).

Since the stuff is so cheap ($10 for 100 feet), you can probably just empirically figure out what length to use to light your match. Start with a long coil attached to your battery and see how fast it gets red hot. If you want it to get hotter or get hotter faster, shorten the length of the nichrome segment.

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