Hot ematch prime without Antimony or Potassium Chlorate

[PyroJoe]

So it's been a long time since I've done much pyro, due to the fact that I just got married a month ago! (Yay for me) and I live 30 minutes from my pyro stuff now. Anyways, my buddy is getting married in a week and wants to make some fireworks for his wedding reception, so I ordered 100 e-match blanks from www.oda-ent.com and quickly realized they don't put out nearly as much heat as my usual 28guage nichrome does.

 

All of the compositions I could find on the net use the 50/50 Antimony Trisulfide/Potassium Chlorate mix for these e-match heads, 2 chemicals I don't have! So I was just wondering if anybody had experience with another comp that would work as well. I was surprised that I couldn't even see smoke, or anything when this little things heat up... so the comp obviously needs to be extremely heat sensitive. Im hoping these will be much more reliable than my nichrome wrapped ignitors that would work about 25% of the time. Any suggestions would be great!

 

Forgot to add that these are the chems I currently have:

Potassium Nitrate

Potassium Perch.

Strontium Carb. and Nitrate

Barium Nitrate

Aluminum (German Dark)

Aluminum 400 mesh

Magnesium 5 micron spherical

Charcoal

Sulfur

Hexamine

NC Lacquer

Zinc Oxide

Edited July 25, 2009 by PyroJoe

[Ralph]

When I make ematch heads i make 2 kinds simple meal (often with added aluminium) or I use some slow but hot (these will light almost anything) ones using the folowing formulla 60 KNO₃ 15 red gum 15 bright flake aluminium 10 sulfur.

 

you could replace the redgum with hexamine (i think) and as far as the bright flake aluminium goes coarser aluminium would make it even slower dark flake would speed it up and would be a good replacement (costs more though). And it might be worth trying with perc (i have a batch that has been siting there for ages so i never tried with perc)

 

 

 

 

edit: i can put a video up when i get back home if you would like

Edited July 26, 2009 by Ralph

[Mumbles]

I'd go with perc over KNO3. It has a lower ignition temperature in most cases than the nitrate. I've had problems in the past with my e-matches corroding with nitrate based e-matches. This is of course with years of storage, so not an issue for you.

 

If I were in your situation, I would use a perchlorate based flash, bound with NC as the first layer. Perhaps 10% sulfur to decrease ignition temperature. Then a layer of BP over the top, perhaps with some of the 400mesh Al to add some additional sparks. I prefer a layer of BP over the top to prevent any sort of incompatable reactions, as I do in fact use some of the chlorate based primes.

[Miech]

Just meal will do, it ignites at 260^oC according to Ian von Maltitz. If you get your wire glowing, you're at at least double that temperature. Binding it with laquer is preferred for waterproofing it, but dextrin will work as well (but keep in mind that the latter method is less reliable due to corrosion of the wire). If you need more heat you can spice up the meal by adding 5% aluminium.

 

I wouldn't use hexamine for igniters, as it doesn't have a reputation of being very stable and it burns quite cool compared to other fuels.

[PyroJoe]

That's the issue here, I can't even see the wire glow or break because it is so small (50 gauge nichrome). I think I'll try out the perchlorate flash with a little sulfur and see if that works. I'll have to go buy some ping pong balls here pretty quick

[Mumbles]

That might just be because you're doing it while exposed to air. It could be burning up faster than it can get to heat. When covered with comp, it will be allowed to get much hotter. I've heard of them working with just BP without issue. I just like a little safety margin. Well, if you can call a hodge podge of chlorate, aluminum and antimony trisulfide in anyway safe.

 

One trick I have learned. Screen the oxidizers and fuels separately, and wet one with the NC lacquer, and stir in the other. It saves the issue of having to sieve such a death mix.

[flying fish]

Kinda something I've always wondered...could a comp with a high percentage of metal powder coated on the nichrome, perhaps prevent it from firing due to conduction? I remember doing a test a while back with bare nichrome sticking into bare BP, and bare FP, and the BP ignighted easier. Of course, it could have just been dumb luck or something...

[Mumbles]

BP also has a lower ignition temperature. I suppose it could have merit of drawing some of the current out cooling the wire in a way.

[FrankRizzo]

FP has a high ignition temperature compared to BP, which would explain the variation.

[psyco_1322]

I believe that 70:30 Al flash has enough metal in it to be conductive if you want to make some bridge-less dip matches.

 

I played with it a long time ago, and did get it to light up on a match. I think I was using bright Al and fired it with my crank blasting machine. So it might take some juice to get it going.

[Bonny]

I've made ematches with nichrome wire and used BP/NC slurry as the pyrogen that worked just fine. I did have corrosion issues though, seems a year later, (most) of them were no good. I did make a batch that the wires were first dipped in NC, dried and then dipped into the BP/NC slurry. I think these were the ones that were still good, but I mixed them all together so I'll never know.

[Mumbles]

A continuity tester should be able to discern them. An ohm meter works just as well.

[Bonny]

A continuity tester should be able to discern them. An ohm meter works just as well.

 

I sorted them out by testing for continuity...and ended up trashing most of them. Good thing though, as it would have ruined my small show or at least wasted a lot of time on set up/fusing with useless matches. I think if I ever make more, I'll dip (all of them) in NC first to protect the wire, then coat with the slurry.

[laser200]

I sorted them out by testing for continuity...and ended up trashing most of them. Good thing though, as it would have ruined my small show or at least wasted a lot of time on set up/fusing with useless matches. I think if I ever make more, I'll dip (all of them) in NC first to protect the wire, then coat with the slurry.

Interesting..I have been making awesome igniters using a slurry of NC and Mill mixed to tomatoe paste consistency. They work evry time..I may have to try dipping them first in the NC and see how that works also...

[Arthur]

I had success with H3 as a compound dipped with NC lacquer. Airfloat fine pine charcoal and airfloat fine chlorate. Take about half a cc of NC lacquer and add a (visually!) equal amounts of charcoal and chlorate separately with stirring there is enough to dip about 100 igs there. (It's too little for me to weigh on my scales!)

 

Whether it would work with perc?? Remember that ALL igniter mixes are very sensitive. Make only as little as you will use in one session. Preferably a millilitre or less.

 

Nitrate igs corrode the wire but ultrafine meal in NC lqcquer works well for immediate use.

[Bonny]

Interesting..I have been making awesome igniters using a slurry of NC and Mill mixed to tomatoe paste consistency. They work evry time..I may have to try dipping them first in the NC and see how that works also...

 

How long have you stored them? Mine also worked great, but after storing for over a year, most were no good.

[vladou]

Hi there,

 

I have the same problem than PyroJoe.

Can I use Armstrong mix as the primer (KClO4 comp) ?

[Mumbles]

It's not even worth it. Too dangerous and sensitive. Black powder can easily be used in a pinch.

[vladou]

Ok, I'll try as soon as I'll have received them.

 

But if it works with only meal, why do we have to put some primer on the top of the e-match head ?