E-Match
Simple, homemade electronic igniters from easy materials.

Background

Electronic ignition systems (igniters, e-match, and squibs) are used by just about every professional fireworks display. They allow quick, efficient, and easy ignition of fireworks at the push of a button. Unless of course you want to be running around with a lighter for an hour. Igniters use a high resistivity element such as NiChrome, tungsten, carbon, or steel. For a really cheap igniter you can even use small strands of copper wire. When current is passed through the elements, they heat up and sometimes explode. The heat ignites a booster composition which in turn ignited your firework. There are many How Tos online about making igniters. Just in case you don’t understand this one, here is one from pyroguide.com. It even has a section on making Nitrocellulose (NC) lacquer. If you don’t want to build your own you can buy them from skylighter.

Version 1: NiChrome

Step 1: Prepare the Wires

Connecting wires Two 3 inch pieces of wire are cut. They are stripped 1/4 inch on one end and 1/8 on the other. It doesn’t really matter the gauge of your wires as long as they can carry more current than your heating element. Here is a good table for AWG current handling. I used 22 AWG wire from RadioShack because that what I had.

Step 2: Connect the NiChrome

First connection to the NiChrome Folding the wire over NiChrome is the most common form of electronic igniter. NiChrome is an alloy of Nickel and Chromium oddly enough. It has a high melting point and high resistance to oxidation. It is perfect for all types of heating elements such as those used in toasters and hair dryers. So if you don’t want to buy NiChrome you can pull apart a toaster. They typically go for about $2.00 at your local Salvation Army. A single toaster can make thousands of igniters. So now that you have your NiChrome, you can attach it to the wires. Soldering won’t work with NiChrome unless you have silver solder and acid flux. Besides, soldering would take too long and the fold technique makes a good connection. Cut of a section of about 5/8 inch of NiChrome. Wrap one end once around the base of the short stripped end of a wire. Then fold the top of the wire down onto the NiChrome and crimp it into place. Before the second wire can be attached it’s a good idea to insulate and support with hot glue.

Step 3: Insulate and Support

Hot glue insulation Both wires insulated Close up of the hole Hot Glue is used to insulate the two copper wires and give some support to the e-match. Just put on a dab of glue and smear it around the wire. Repeat Step 2 for the other wire and then glue it as well. The last step in support is to fold the wires over and glue them together. Make sure to keep the NiChrome free of glue. Alternatively you can use NC lacquer to insulate and support and skip the hot glue step.

Step 4: Connect your Favorite Firework

Connect to a fuse Now your favorite firework can be inserted into the hole. Apply some power and you are done. The toaster NiChrome wire I used works great with a 6 V lantern battery. The wire actually isn’t destroyed. It just heats up. It takes a couple seconds. On the plus side it doesn’t require any intermediate composition for ignition. You will just have to experiment with your own since no toaster is built the same. They are cheap so feel free to experiment.

Version 2: Christmas Lights

A cheap alternative to the NiChrome e-match is the Christmas tree light igniter. The tungsten filament inside the bulb doesn’t burn because of an inert environment or vacuum. Simply breaking the bulb can fix this problem! Christmas lights make great igniters that come with their own wires.

Step 1: Materials

Tangle of Christmas Lights Group of Lights What do you do with that old string of tangled, burnt out Christmas lights? Make pyrotechnic igniters of course. On a side note: just before I learned about these igniters I threw out a bunch of dead lights. Maybe about ten strands. That will teach me not to be a packrat. Anyway… Disconnect the bulbs from the wires. Give them a good pull by the plastic base and they should come free. Throw out the bulbs with burnt elements or damaged connecting wires.

Step 2: Cut Glass

Glass Scoring Finger Position Glass After the Break Here is a great resource for cutting glass tubing. Make a score line with the corner of a file at the top of the bulb. It does not have to be deep. Wet the scratch down with saliva or water. Then grip both ends of the bulb and push your thumbs into the side opposite the scratch. Its helpful to do this with a t-shirt wrapped around the bulb because sometimes they shatter. You want to leave the maximum amount of glass on the bulb to fill with composition.

Step 3: Connections

Blank Christmas Light Replaceable E-Match The cool thing about Christmas light igniters is that they already have a connector. Cut the wires of each bulb holder from the light strand and strip them about 1/2 inch. Insert your igniter and presto: a reusable connector. Each time your use an e-match, the bulb can be taken out and other inserted. No need to clip and strip wires.