Electric Igniters/matches for fireworks?

mpitfield said:

We ran out of igniters at a LP kids demo launch where they built little badminton birdie rockets that fly on 1/2A motors. The young girl who's rocket it was was very upset, literally in tears as she waited until the very end. So I loaded up an ematch not sure what would happen and man did that little sucker go high. It must of gone an extra 30 feet, considering they only went 30 feet to begin with...she went from tears to all smiles. So I have no idea if they will work in every situation but it certainly worked + in my case.

Click to expand...

If you find yourself in this situation again, try using the lead from an Estes igniter. Bend it in half, insert it like a regular ignter and put the clips as close to the nozzle as you can. If you've got a good battery it will light the motor.

blackjack2564 said:

All 3 types shown in post #4. All were Chinese. I must add this caveat...."they type that I have/use".
I cannot confirm use with ALL types out there. I am comfortable knowing the type I have on hand are safe when used properly with out being overly sensitive.

I'm sure there are incidents that happened occasionally, there is always an exception to the rule.
But by & by, I'm convinced with reasonable care it ain't happening.

I personally DID this.... no here say or reading about it. Try as I might, could not make it so.

"in god we trust, all others bring data"

I have also seen impact ignitions.
This is usually brought on by the "concussion" of another charge firing near by, with enough force to make anything nearby auto-ignite. Not necessarily the match, more likely another BP charge of some type used for lifting or propelling something "up".

Click to expand...

Nice testing regimen Jim. Only ematches I've ever seen go off with a hammer were my "totally" made from scratch that I mastered but have never flown due to the commercial alternatives currently available. The toothpick stirring "rods" I used from one of the reagents I'd let dry then hit with a hammer for a loud "pop". I still have some lying around and sometimes go outside with a AAA battery to admire my handiwork. Took about 4 winters to master the technique that I considered a backup skill "just in case".
Many of them would flare up very nicely and slowly with nary a pop. If I would have used them for flight, I would have done two per charge or flown with two deployment altimeters only. With the commercial alternatives, it just isn't worth the time and the
trouble to make. I would never trust any of the commercial blanks available out there based on my testing from several sources. I think the only blanks are seconds the commercial match makers "reject". My success rate went up greatly when I nichrome wrapped, soldered and sheared my own blanks with my "secret" wire. Gotta also test the resistance of the completed blanks and reject those that read "high" or use them for a 12V motor starter. There is a thermite mixture out there that an ematch will set off
but it is very dangerous for one to routinely use. Just buy 'em and fly 'em. Don't bother mak'in em Kurt

Nessalco said:

Jim, the wire in standard ematches (.25A no-fire, .6A all-fire) is usually around #50 gauge, and by itself doesn't produce enough heat to ignite BP - or making your own ematches would be easy Some sort of sensitive first-fire must be used - these are the compounds that are most sensitive to handling. Still, as I've said, not all that sensitive.

Ematches are made to fire in series, sometimes in large numbers. No single device can consume too much power or the whole chain fails.

Click to expand...

I must apologize for my error.....previously I tried my hand at making them with 40 ga after reading several papers on "how to".

I'm the guilty one.... not doing ENOUGH research.

Look at the word. e-match is the contraction of electric match. It is simply a hot wire coated with a match composition. It products the energy of a friction match. An e-match will ignite anything that a friction match will ignite.

A match, fuse or e-match will ignite a BP ejection charge, or a BP motor. A friction match will not reliably ignite an APCP motor because APCP need a more energetic heating source to ignite than a match can supply. Neither will an e-match. You may say wait a minute, CTI uses an e-match to ignite many of their motors. That statement is technically incorrect. The e-match that is included in many CTI motors does not ignite the APCP motor, but rather ignites a compressed BP pellet (a BP motor or motor starter pellet if you will) inside the APCP motor bore. The hotter, more energetic gases from the BP motor starter pellet in turn deflagrates the bore of the APCP grains and produces a prompt motor startup.

So you need an igniter (or motor starter) for reliable APCP ignition. An igniter or motor starter in it's simplest form is simply a boosted e-match. You can make an igniter (or motor starter) from an e-match by coating it with a booster pyrogen. This is the method used by AT, Loki, Gorilla, and the larger CTI motors. What is not appreciated is that there is not such thing as a one-size fits all igniter/motor starter. The quantity of booster pyrogen required increases in proportion to the bore volume to the 2/3s power. (which reflects the surface to volume ratio as per NASA SP-8051, page 59.) If you use too little booster in a large motor it will not ignite or chuff badly. If use too much booster in a small motor it will likely overpressurize and CATO. A great example of motor starters with varying amounts of booster material is the Quickburst line of motor starters. His motor starters are unregulated and come in 4 size that will reliably and promptly ignite small APCP reloads to the largest L3 motors.

I hope this simplified explanation helps your understanding.

Bob

cwbullet said:

I have used ematches with a secondary dip. They will light just about anything with a little magnelite dip.

Click to expand...

+1 for sure...
I use the ematches that CJ (BlackJack) sells on all of my ejection charges
and also dipped in my own pyrogen mix to light composite motors.....
I have used hundreds of these,,
I just recently made one specifically for an Aerotech 75 / 3840 L 1390 G...
If you saw the size of the head on this thing you wouldn't believe it..
It went off instantly not a pop,, but with a whoosh so strong it shock the rocket on the pad,, perfect,,, like a flare,,, with magnesium in the mix yet.....
Motor didn't light.......
First failure and it had nothing to do with the match.......
My buddy Fred T had some funny looking cord he tied to a match of his own......
Dat worked...
Unbelievable how hard it can be to get Green propellant cookin.....

Teddy

Good posts all, but lest we forget:

the Chinese have been making fireworks for thousands of years, and if there's one thing I kinda trust them to do, it's get the stuff IGNITED

I use Chinese made igniters bought in bulk on FeeBay...

You guys are funny.
CJ makes them. Uses them. Other people use his e-matches. He's used the to light stages, clusters, AP, and BP. He's done extensive testing (real testing, not reading in paper testing). Seems like for the OP's issue, one could easily defer to CJ.
...
...
Or people can just try and correct his info... Geez. You'd think lighting an F motor wouldn't cause such a stir...
Oh, wait, did he say F? Yeah, he did. Oh, okay. Just checking.
Two cheers for rocketry!

I order similar stuff and have never had a failure.