Improving igniters

[boatgeek]

Since the Firewires are on my way from the garage to dinner, I have results. It took three strikes with the hammer to set off the Firewire. I wasn't really whaling on it, but I wasn't gentle either. It appeared that the flame was a little less than in @lakeroadster's demo, but it was a little hard to tell because the hammer was between me and the flame. The Firewire is definitely shock sensitive, and probably not markedly less so than the e-matches demo'd above.

If you have the non-Firewire version then be sure to keep the sleeves on and store them where nothing can drop on them and where they won't get banged around. If someone has a fire or explosion and ATF investigates then illegal possession and improper storage of ematch makes the person liable. Getting insurance to pay in those cases in problematic. Gluing fingers back on is also a PITA.

This advice is probably good for the Firewires too. I think my storage at home is OK (in a box, with sleeves on, in a metal shelving unit so nothing can really fall on it), but I will definitely rethink how they travel to a launch.

 

[lakeroadster]

Are MGJ ematches similar in sensitivity? I'm not expecting anything to bang on them in the metal cabinet in my garage, but I'm also rethinking storage after seeing this.

I emailed them, (MGJ) I'll post their response once I receive it. If you have one.... drop the hammer!

We have used MJG ematches for large shows with a thousand cues or more. They are very reliable and the company is very respected. Their quality is excellent. They make a few types - if you use their standard match, then, yes, they are sensitive and they require an ATF license to purchase. They make a non-explosive version called MJG Firewire which is not explosive or nearly as sensitive and they require no license to purchase. I have no experience with those since they are relatively new on the scene.

If you have the non-Firewire version then be sure to keep the sleeves on and store them where nothing can drop on them and where they won't get banged around. If someone has a fire or explosion and ATF investigates then illegal possession and improper storage of ematch makes the person liable. Getting insurance to pay in those cases in problematic. Gluing fingers back on is also a PITA.

Welp, looks like it's hammer time! <-- those are safety glasses, by the way.

They are Firewires. I will test and report back. It won't be a video, because I'm not as cool as @lakeroadster.

The folks at MGJ responded that their BP Motor Starters are susceptible to impact and friction ignition.

 

[bad_idea]

The folks at MGJ responded that their BP Motor Starters are susceptible to impact and friction ignition.

Confirmed the impact part tonight. A fairly light hammer blow set one off:

 

[lakeroadster]

A good read... posted from another thread...

I was one of the reports of an E-match firing from static. To prevent any confusion, I want to clarify the story I heard second hand was not using one of the MJG Firewire initiators available without an ATF license.

I do not recall the manufacturer, but the e-matches in question were standard ones used in the firework industry which require the necessary licenses to purchase and store. The differences are small, but how the e-matches are made is different.

I do believe the report I heard, it was from the owner of the company I was shooting with and it happened to him. I just wasn't there to witness it and wasn't able to reproduce it. That said, I have seen standard e-matches ignite from friction and impact. It isn't always easy to make it happen, but simple care makes them safe to work with. The biggest thing to remember is to treat them as you would a loaded gun. Once the e-match is in place, think about your body and your surroundings. If it were to ignite, what would happen? If the BP charges aren't in place yet, the match will burn for a second. Will it destroy anything? If the charges are in place, where will the nosecone or payload section end up? These scenarios are probably easier to manage. Staging and airstarts gets more complicated.

I don't think an E-match is likely to ignite just sitting there, even when connected to an altimeter that is powered off. You're more likely to get an unintended ignition when you're inserting the coated tip into something, the shrouds protect from friction and impact, but if you must remove it, this is when you're more likely to have one go off. (still a small chance) If you do need to slide the shroud back, look for any chips on the pyrogen coating. I would discard it if it is damaged. For rocketry, I have read reports about ematches igniting when an altimeter powers up. In the fireworks world, there are reports of ematches occasionally firing when the leads are first inserted into the slat, even when the slat is disconnected from the module where the power comes from, when the modules are first powered up, or during continuity checks.

That was long winded. TL/DR

Ematches require some common sense and simple precautions, but can be used safely.

 

[Ladykate]

A good read... posted from another thread...

lakeroadster quoted NateB: "The biggest thing to remember is to treat them as you would a loaded gun."

I am a gun nut and I am a pyro. Both skills were learned and used in different contexts and I hadn't equated them exactly that way. But I agree. Situational awareness and mitigation of risk are key.

 

[rocket_troy]

One more thing I'll add about the storage and handling of Ematches is try to always store with the lead wires together (like how they come). If the wires are separated, then twist the separated section together.
This is to avoid the potential for the wires to act as a dipole antenna to absorb RF radiation from nearby high power sources (like a 2way radio in close proximity). If the wire ends run in opposite directions at the 1/4 wavelength of the emitted radiation, there is the potential for the wires to pick up non trivial energy from the transmission. Very unlikely to be an issue, but good housekeeping.

www.propulsionlabs.com.au/Misc_Video_And_Images/RF_Test.MOV

TP

 

[Ladykate]

One more thing I'll add about the storage and handling of Ematches is try to always store with the lead wires together (like how they come). If the wires are separated, then twist the separated section together.
This is to avoid the potential for the wires to act as a dipole antenna to absorb RF radiation from nearby high power sources (like a 2way radio in close proximity). If the wire ends run in opposite directions at the 1/4 wavelength of the emitted radiation, there is the potential for the wires to pick up non trivial energy from the transmission. Very unlikely to be an issue, but good housekeeping.

www.propulsionlabs.com.au/Misc_Video_And_Images/RF_Test.MOV

TP

Good example in the video. When doing explosive disposal, we always ground connection wires until the range goes hot.

 

[majordude]

Is thermite available anymore?

 

[rharshberger]

Is thermite available anymore?

if you make it...or were you referring to Thermalite?

 

[heada]

Is thermite available anymore?

https://www.skylighter.com/products/thermite-kit-makes-8-lbs
There are so many other options besides thermite that it doesn't make sense in rocketry anymore. ProCast by Quickburst is a much better option.

http://quickburst.net/qb/procast-order-page/

 

[4regt4]

https://www.skylighter.com/products/thermite-kit-makes-8-lbs
There are so many other options besides thermite that it doesn't make sense in rocketry anymore. ProCast by Quickburst is a much better option.

http://quickburst.net/qb/procast-order-page/

ProCast is the Real Deal...

Mix it thick or thin, depending on how much you want on the igniter. And it really does not take much.

Hans.

 

[majordude]

ProCast is the Real Deal...

Mix it thick or thin, depending on how much you want on the igniter. And it really does not take much.

Hans.

What dat?

 

[4regt4]

What dat?

Don't have a link right at my fingertips, but Google Quickburst, which is the company. Or a Google of ProCast itself likely will find it.

Hans.

 

[majordude]

Don't have a link right at my fingertips, but Google Quickburst, which is the company. Or a Google of ProCast itself likely will find it.

Hans.

Ah! Where is the best place to purchase this? Apogee?

 

[4regt4]

Ah! Where is the best place to purchase this? Apogee?

No, directly from Quickburst. Great service.

Hans.

 

[jsdemar]

What dat?

ProCast is based on my BKNO3+Viton igniter formula. It is fine amorphous boron plus fine potassium nitrate with Viton fluoroelastomer as a binder. It is similar to what is used in professional rockets but doesn't require a press (too risky). The Viton has 65% fluorine in its molecular formula which adds to the reaction as an oxidizer. The mix is diluted with acetone as a slurry to dip on igniter heads or to cast into pellets. It can be dipped onto an ematch for instant on.

ProCast is available in 3 sizes direct from Quickburst or from Apogee Rocketry. (I'm not affiliated with either vendor).

 

[cwbullet]

https://www.skylighter.com/products/thermite-kit-makes-8-lbs
There are so many other options besides thermite that it doesn't make sense in rocketry anymore. ProCast by Quickburst is a much better option.

http://quickburst.net/qb/procast-order-page/

Concur. And safer. I also concur with ordering directly from Quickburst. Great service and he supports his product.

 

[majordude]

ProCast is the Real Deal...

Mix it thick or thin, depending on how much you want on the igniter. And it really does not take much.

Hans.

So you mix it and quickly dip an Estes igniter into it and set aside to dry? How long does the mix last (or do I have to use it all up in one sitting)?

 

[rharshberger]

So you mix it and quickly dip an Estes igniter into it and set aside to dry? How long does the mix last (or do I have to use it all up in one sitting)?

I store mine in a pill bottle within another pill bottle (double seals), I add acetone on a monthly or bi-monthly basis, and have used the same mix for over 2 years (I use the BKNO3-V formula from jsdemar, which is what ProCast is based on), I DO NOT let it dry out in the bottle, I have let it get toothpaste consistency on several occasions, and it has reconstituted nicely. I did do an experiment with it letting it dry fully in a OPEN container and was able to again reconstitute it, best practice is to use it up or I stick a ematch in the bottle and stick it in a hole with a VERY long wire, and set the batch off.

 

[jsdemar]

So you mix it and quickly dip an Estes igniter into it and set aside to dry? How long does the mix last (or do I have to use it all up in one sitting)?

It lasts forever. Add acetone again when it dries out. A small kit will dip 100's of Estes igniters. The dipped igniter dries in a few minutes. For larger motors, do multiple dips with most of the acetone evaporated between each.

See: Procast mix procedure.

 

[rharshberger]

It lasts forever. Add acetone again when it dries out. A small kit will dip 100's of Estes igniters. The dipped igniter dries in a few minutes. For larger motors, do multiple dips with most of the acetone evaporated between each.

See: Procast mix procedure.

John, how friction sensitive is the dry mix if it has been mixed and allowed to dry out?

 

[jsdemar]

John, how friction sensitive is the dry mix if it has been mixed and allowed to dry out?

With the viton coating the dried out mix, it shouldn't be friction sensitive. But all pyrogens, wet or dry, are static (ESD) sensitive to a certain extent.

 

[rharshberger]

With the viton coating the dried out mix, it shouldn't be friction sensitive. But all pyrogens, wet or dry, are static (ESD) sensitive to a certain extent.

Friction was my concern if it dried out in the pill bottle. I use pill bottles because they seal well, the seal seems impervious to the solvent, and the pill bottle is made of HPDE, which doesn't seem to be affected by the solvent either.

 

[cwbullet]

If your mixture drys, just add acetone and let it sit overnight. All of mine have softened enough to mix. I use a glass stir rod. As long it does not take much effort to mix after a night in acetone, you are good.

If it is hard to stir, let it sit longer. You might need to keep replacing the acetone.

 

[rharshberger]

If your mixture drys, just add acetone and let it sit overnight. All of mine have softened enough to mix. I use a glass stir rod. As long it does not take much effort to mix after a night in acetone, you are good.

If it is hard to stir, let it sit longer. You might need to keep replacing the acetone.

Thats what I do as well, I use a brass rod though.

 

[ksaves2]

ProCast is based on my BKNO3+Viton igniter formula. It is fine amorphous boron plus fine potassium nitrate with Viton fluoroelastomer as a binder. It is similar to what is used in professional rockets but doesn't require a press (too risky). The Viton has 65% fluorine in its molecular formula which adds to the reaction as an oxidizer. The mix is diluted with acetone as a slurry to dip on igniter heads or to cast into pellets. It can be dipped onto an ematch for instant on.

ProCast is available in 3 sizes direct from Quickburst or from Apogee Rocketry. (I'm not affiliated with either vendor).

Sheeeeoooot, Get a kit like John recommends. Will make your life easier. I did BKNO3+Viton igniters from scratch back in the day but a kit would be so much easier in this day and age.

Finding raw Viton pellets was a real PITA back then. Boron cost a lot of $$$$$$ though a little goes a long way. KNO3 is better if it's dried a bit in a chemical oven but it's not really that necessary.
I've tried several igniter kits of various types and they all work to get a rocket off the pad if mixed, dipped and used properly.

Now staging is a different matter I will not discuss out in the open. Those chems can be pretty sensitive if an ematch can set them off to start an upper stage from an altimeter/controller. I'd definitely get under the tutelage of someone who stages APCP motors consistently. I've done some ground testing but have never flown a staged flight. Did some testing with an ematch based staging igniter doing a ground test with an ARTS 2 altimeter connected to a computer. Commanded to start the igniter and it popped up, burned like hellfire and hit me in the left ear! Pushed it away with my arm and the ear wasn't too bad and didn't burn my arm. Stupidhead here was using too short of cables and got "longer" ones for further testing. Earmuffs might have saved me if I had worn them. Longer cables helped for further testing. Haven't messed with it in years as I've never progressed to staging APCP. Kurt

 

[Rocketjunkie]

After trying several pyrogens, I have settled on ProCast for my tiny starters in my 18 mm D grain motors. How I make them is in my 18 mm motor thread https://www.rocketryforum.com/threads/18-mm-motors.158722/ starting at post 58. This is in the research forum so you will need access.

 

[cwbullet]

Finding raw Viton pellets was a real PITA back then. Boron cost a lot of $$$$$$ though a little goes a long way. KNO3 is better if it's dried a bit in a chemical oven but it's not really that necessary. I've tried several igniter kits of various types and they all work to get a rocket off the pad if mixed, dipped and used properly.

Procast is worth the price. I bought a significant amount of Boron a few years ago off eBay to make BKNO3. I still have it. I certainly do not think it is worth 100+ per pound.

https://www.ebay.com/itm/2343372967...R17ZqT5t0vRblIcYuMUZ3txjboTk|tkp:BFBMjOGMsvtg
I dry by KNO3 in a toaster oven for a couple of hours the night before. It makes it significantly lighter.

 

[waltr]

Yes, ProCast kit is nice and even the smaller kit makes a lot of ignites. If it dries then easy to add acetone to get it back to a slurry for dipping.

For small motors like the Qjets, I use 28ga wire-wrap wire and 34Ga nichrome then dip. These are small enough to fit into the Qjet nozzles and have always light the motor.

For Air-starting APCP, I use the 24ga 'shooter' wire (MJG Ematch wire) with 40ga nichrome then dip. The Eggtimers with 2s LiPo fire these very quick and the ProCast always gets the motor going.

I do make igniters with different amounts of ProCast on them. I do one dip of thinner Procat for motors with small nozzles and multiple dips and/or thicker Procast for larger nozzles.
I've given away a number of these igniters at club launch when an AT igniter failed to get a motor lit. The ProCast ones always lit the motor.

 

[quickburst]

Yes, ProCast kit is nice and even the smaller kit makes a lot of ignites. If it dries then easy to add acetone to get it back to a slurry for dipping.

For small motors like the Qjets, I use 28ga wire-wrap wire and 34Ga nichrome then dip. These are small enough to fit into the Qjet nozzles and have always light the motor.

For Air-starting APCP, I use the 24ga 'shooter' wire (MJG Ematch wire) with 40ga nichrome then dip. The Eggtimers with 2s LiPo fire these very quick and the ProCast always gets the motor going.

I do make igniters with different amounts of ProCast on them. I do one dip of thinner Procat for motors with small nozzles and multiple dips and/or thicker Procast for larger nozzles.
I've given away a number of these igniters at club launch when an AT igniter failed to get a motor lit. The ProCast ones always lit the motor.

Please contact me via email.

[email protected]