Ignitor Pyrogen

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Ez2cDave

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Get the smallest amount of smokeless powder you can find and make your own NC lacquer. A quart of 10% NC lacquer needs about four ounces of smokeless powder, and is a lifetime supply for most.
Terry,

Does the "speed" of the Smokeless Powder matter ? ( "Blue Dot" vs "IMR 4350", for example )

Is Acetone the solvent used ?

Dave F.
 

timbucktoo

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Terry,

Does the "speed" of the Smokeless Powder matter ? ( "Blue Dot" vs "IMR 4350", for example )

Is Acetone the solvent used ?

Dave F.
Not so much speed of powder but rather a single base powder (vs. double base). Single base is made from nitrocellulose whereas double base is made from a combination of nitrocellulose & nitroglycerine and yes, Acetone is used to dissolve the powder.
 

Ez2cDave

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Not so much speed of powder but rather a single base powder (vs. double base). Single base is made from nitrocellulose whereas double base is made from a combination of nitrocellulose & nitroglycerine and yes, Acetone is used to dissolve the powder.
Tim,

That was very helpful . . . Thanks !

Dave F.
 

rocket_troy

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Nitroglycerin is added to tame nitrocellulose's ludicrous pressure exponent to make practical rocket propellants. NC on its own (single base) exhibits a pressure sensitivity that’s normally way too high for rocket applications ie. it will burn quite slowly under 1 atm but fast enough to be a useful *gun* propellant under pressure. Where this is important to igniters/starters is that if your system is dual compound and your (inner) primary mix is NC binded, then you want your secondary coating to be “forgiving” (flexible or weak etc) enough as to not confine the primary compound too much otherwise permitting its pressure to rise beyond a certain threshold or the primary compound might “pop” on you ie. burn too quickly to ignite the secondary properly. The same can occur with mono-compound igniter/starters that are NC based in that if the head is too large, the inner compound exposed to the electrical bridge can over-pressurize and produce more of a pop than a complete burn of all the compound.

TP
 
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rocket_troy

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I don't think I have ever seen this and I dip a lot of igniters in NC lacquer. Nitroglycerin is not an option to me.
I wasn't suggesting to add NG to igniters. That was just a reference of why it's added to rocket propellants.
The reason why you haven't seen it could be anything - grade and purity of NC, composition and % of NC binder within the composition, dipping technique or the size of your igniters ie. what you define as large.
It's certainly something I've seen quite a bit over the 25 or so years I've been dipping NC based igniters however I've always used non synthetic high grade NC dope.

TP
 

cwbullet

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I wasn't suggesting to add NG to igniters. That was just a reference of why it's added to rocket propellants.
The reason why you haven't seen it could be anything - grade and purity of NC, composition and % of NC binder within the composition, dipping technique or the size of your igniters ie. what you define as large.
It's certainly something I've seen quite a bit over the 25 or so years I've been dipping NC based igniters however I've always used non synthetic high grade NC dope.

TP
% wise. I would have to check my bottles. I never paid attention to it. It lights the motors.
 

rocket_troy

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My favourite drop uh..humm dope :) 20ish yo vintage:

NC_Dope1.jpg
NC_Dope2.jpg


likewise... probably closed down 15 odd years ago [sigh]

Made great little igniters though (slowmo)

 
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Ez2cDave

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I don't think I have ever seen this and I dip a lot of igniters in NC lacquer. Nitroglycerin is not an option to me.
Chuck,

What about the possibility of "steeping down" Cardiac 1/125mg Nitroglycerin tablets, as an NC supplement ?

Dave F.
 

cwbullet

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Chuck,

What about the possibility of "steeping down" Cardiac 1/125mg Nitroglycerin tablets, as an NC supplement ?

Dave F.
No idea. Not sure how or if you should do that.
 

dhbarr

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Sublingual NG contains all kinds of soluble whatnots, such as
  • calcium stearate
  • colloidal silicon dioxide
  • hydrogenated vegetable oil
  • lactose monohydrate
  • magnesium stearate
  • microcrystalline cellulose
  • polyethylene glycol
  • pregelatinized starch
Also please recall that touching or breathing pure NG can cause
  • abdominal pain
  • convulsions
  • death
  • diarrhea
  • dizziness
  • headache
  • lightheadedness
  • mental confusion
  • nausea
  • tremors
  • vomiting
And of course it is a highly reactive chemical and a violent explosion hazard which is regulated by a lot of different folks.

TL;DR -- Don't.
 

Mike Haberer

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Awareness: most pingpong balls are NO LONGER made of NC lacquer.
This:

The International Table Tennis Federation changed the specifications for table tennis balls to be made from a less flammable (as nitrocellulose) plastic. Any ball marked "40+" are the new specifications. You might be able to still find the old 40mm or even 38mm that are still made of cellulose nitrate.

and this...


I ordered this. I figure 144 will last several lifetimes...
 
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Jay Rairigh

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Can't you just use the NC lacquers they sell at the hardware stores? I believe after the solvents evaporate, you are left with an NC film.
 

cwbullet

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Purchased a pint over a decade ago, after 100s of igniters, still over half the pint left. I don't think they sell it any longer.
they still sell it.
 

SharkWhisperer

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Nitroglycerin is added to tame nitrocellulose's ludicrous pressure exponent to make practical rocket propellants. NC on its own (single base) exhibits a pressure sensitivity that’s normally way too high for rocket applications ie. it will burn quite slowly under 1 atm but fast enough to be a useful *gun* propellant under pressure. Where this is important to igniters/starters is that if your system is dual compound and your (inner) primary mix is NC binded, then you want your secondary coating to be “forgiving” (flexible or weak etc) enough as to not confine the primary compound too much otherwise permitting its pressure to rise beyond a certain threshold or the primary compound might “pop” on you ie. burn too quickly to ignite the secondary properly. The same can occur with mono-compound igniter/starters that are NC based in that if the head is too large, the inner compound exposed to the electrical bridge can over-pressurize and produce more of a pop than a complete burn of all the compound.

TP
There is no problem using double-base. The NG det rate is just slightly greater than NC, and it makes a good solvent for NC for powder manufacture. I've seen zero difference for igniters using NC lacquer made with single-base (NC-only; I use IMR-3031) or double-base, which usually contain between 15-35% NG, depending. And in fireworking, both are used for binders when making dragon eggs/crackle, and both work well, though some swear they see improved ignition with double-base (it's a strobe burning effect). What is an important factor in smokeless selection for NC lacquer is that you want the thin fast-burning wafers in shotshell-reloading powder instead of the hard extruded pellets (slower burning) designed for magnum rifle cartridges. The wafers go into solution after about 5 minutes of shaking. I use Hodgdon's International, with green & orange wafers that dissolve to give a pleasing beige lacquer instead of the typical black of most powders. The common extruded pellets are a pain to dissolve, often requiring shaking every 30 min, sometimes over the course of several days. All contain a preservative, mandatory for any NC solution because unprotected NC loves to lose its nitrate groups as nitrogen oxides (that react with/dissolve in atmospheric water to form caustic and highly reactive nitric acid) with storage--usually it's diphenylamine, and it works well, both in powder and solution. For reproducibility in making the standard 10% solution, your calculations should be w/w and account for acetone's lower specific gravity (0.785). Remember that acetone is particularly hygroscopic, so protect it from atmospheric moisture or it'll absorb an unlimited amount of water. For a binder of pyro stars, this is not so much an issue; eventually the water will evaporate. But for metal wiring, moisture + oxidizers = corrosion and can cause device failure with long-term storage. If using dollar store fingernail polish remover, be certain that it says 100% acetone. Still, it's from China, and that's no guarantee. Moisture absorbing beads are available, but some might consider that overkill. Non-hygroscopic MEK (methyl ethyl ketone) is available at HD etc., and evaporates slower than acetone; can use alone or in a mix with acetone to adjust drying times. With dipping, one generally wants quick drying time. Solvent can be added back if it evaporates out of your pyrogen slurry too quickly. Once dissolved in lacquer, NG in double- and triple-base (the third chem is nitroguanidine) is easily absorbed through the skin and can give you a "dynamite headache" if you don't use appropriate caution (and gloves).

Ping-pong balls (old style celluloid) are still available but you're better off buying a known brand that others have used. Celluloid is simply low-nitration NC (mostly dinitrocellulose instead of the trinitrocellulose in smokeless) that is dissolved and polymerized with camphor. They will have a distinct camphor (mothbally) smell, particularly if cut open or punctured. And they will burn with a vigorous yet controlled orange flame that emits essentially zero smoke and leaves very little ash. Plastic PP balls are not considered hazardous, so manufacturers don't need to disclose the polymer used, though polystyrene, cellulose acetate, and polyethlylene terephtalate, and ABS (acrylonitrile butadiene styrene) are likely candidates. All burn but burn like crap. Nobody wants to smell burning plastic (ahem, folks using Testor's paint...), and it produces a suboptimal burn with any pyrogen. And PP balls are less than 3g each, so there's that...

NC guitar lacquer is available from Amazon, but it's rather pricey at around $25/quart + shipping. Mohawk/Behlen (I think product #6011, or close....EDIT: Product #M610-1405, pricing was correct at $25) is also proven. It is decently flammable and probably is closer to celluloid than smokeless in terms of nitration level. And it contains various other solid components and a mixed-solvent (that doesn't evaporate quite as quickly as pure acetone). I have used it for binding dragon eggs to good effect, but because of uncertain additional components, would never use it with certain reactive pyrogens for dipping. Might work great, but just never tried... https://www.amazon.com/Mohawk-Finishing-Classic-Instrument-M610-1406/dp/B07PG9Z64V/ref=sr_1_1?crid=2828O0F0PHBAT&dchild=1&keywords=behlen+mohawk+string+instrument+lacquer&qid=1617741233&sprefix=behlens+mohaw,aps,100&sr=8-1 . The Colortone lacquer that Mike H provided above costs $41/quart.

Some fingernail polishes are NC-based (forms a nice durable covering on nails, guitars, and wire alike), and will generally list this ingredient if they contain it (legal requirement due to flammability). Unsure what NC concentration, nitration level, and ancillary chems/pigments. Yeah sure, only a buck at the dollar store, but I don't ever plan to experiment with it.

NC-based model airplane "dope" is still available, reasonably flammable, but astronomical in pricing.

Pure NC and NC lacquers for fireworking are available from some vendors. The pure NC ships wet by law due to flammability. It doesn't have stabilizers included, so that's an issue. Unopened pound still in my freezer under some hams, so never been tested... They claim it's 12.5% nitration, but would need to estimate myself with a burn test--I would be surprised if this claim was true. By contrast, the NC in smokeless powder is probably approaching 13.5% nitration, the theoretical maximum. The lacquers usually contain stabilizers. The one vendor that probably still sells this is entirely unreliable (sorry Firefox, you are horrible), and will be happy to take your money and forget you exist, then ghost you completely when you try to get an update. They received a super-punitive injunction for selling M-80 kits over a decade ago. Their temporary injunction expired but CPSC/DOT didn't appreciate that the Purringtons took this to mean they could resume selling M-80 kits, which they did. Not smart. Their injunction is now permanent and put a serious kibosh on their business, from which they have not and probably never will recover. Avoid at all costs.

Trying to extract usable quantities of NG from angina meds is a fool's errand. Milligram quantities per tablet, patch, or spray dose. Expensive. Many of the binders/carrier molecules are burn inhibitors (silicon dioxide, aka sand, anybody?) with variable solubility in acetone or MEK. Not recommended. And NG is an oily liquid that will never dry to a hard shell like NC; it's fine in combination (double-base) but not alone for dipping/binder purposes.
 
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heada

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Kelly

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There's no need whatsoever for NG in igniters. The pressure exponent issue doesn't come into play when we're talking about the miniscule amounts used to dip an igniter, and when that ignition occurs inside of a motor that is essentially at zero pressure. In addition to the possible health concerns ("dynamite headache") mentioned, I have heard stories about lacquers made from double-base propellants separating out into a NC and a NG phase during long-term storage; you probably don't want a can with an NG layer sitting around in your shop.

Stick to single-base NC powders if you're making your own NC lacquer for igniter dipping.
 

jsdemar

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All previous discussions with details on igniter formulations have been in the Research Forum here. If you are L2 NAR/TRA, request access and do some searching.

NC from single-base powder is the sure way to know what you're getting. $27/lb of Hodgdon H110 (or Winchester 296) is equivalent to $1000 of unknown formulation ping pong balls. Likewise, the guitar lacquers have other additives and just as expensive. Split the cost with someone if $30 for the single-base powder is a big dent in your rocketry budget.
 

BMcD

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This:

The International Table Tennis Federation changed the specifications for table tennis balls to be made from a less flammable (as nitrocellulose) plastic. Any ball marked "40+" are the new specifications. You might be able to still find the old 40mm or even 38mm that are still made of cellulose nitrate.

and this...


I ordered this. I figure 144 will last several lifetimes...
Some of the reviews of those ping pong balls specifically mention that they are plastic not NC. Is your experience that they are NC?
 

cwbullet

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Where do you buy the nitrocellulose already in solution?

Thanks!
I like the flexible stuff. I just order and received to bottles from Firefox-fX.
 

Steve Shannon

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cwbullet

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RobertH3

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So I have Watco lacquer and a ton of Estes starters. Should I remove the starch first??? I don't need these for regular launches, but for the pics below I think I need the increased reliability. Alternate is to use FirstFire micros but that is costliness... I think the "7" cluster can work with Estes. The "12" will need longer starters. The USR Warp 7 (left) - I used glue prime/glue rivets/paper hinges due to weight and fin span. Thought about TTW but instead built as spec'd. Cheers / Robert

IMG_20210505_104018.jpg
 

ksaves2

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Chuck,

What about the possibility of "steeping down" Cardiac 1/125mg Nitroglycerin tablets, as an NC supplement ?

Dave F.
I tried hitting pills with a hammer and burning them with no dice. Like posted, there are so many excipients in NTG pills for symptomatic relief of angina pectoris I doubt they would be a useful source for motor starters. Yes, I slipped one under the tongue one time and had a mild headache for a short time and fast heartbeat. Made sure I was well hydrated first so I wouldn't pass out. Wanted to see what patients experienced when they took the stuff for chest pain. No big deal and once was enough for me.

I found it easier to get the components for some of the posted formulas for igniters out there. The BP use looks intriguing to me.

Nobody bats an eye for anyone who orders BP down here in Central Illinois since there is a lot of hunting where I'm at along with folks who reload. Surprisingly, there isn't a shooting range nearby that is accessible although there is a range next to the prison where the staff has to maintain qualification. That's not open to the public though. Been told they use Ruger Mini-14's in the towers. If there was a range, I might have taken up another hobby!

I felt guilty as heck when I ordered 4F online first time but since I use it for ejection charges and not for nefarious purposes, no one bothers me.

I did learn if I have to dispose of charges to bury them in the ground like say one has a prepped rocket that wasn't flown due to time constraints at a launch and sits for 6 months. In that case, I start over and dispose of the charges. If ignited out in the open, they do go "BANG". Stupidhead was so used to ground testing ejection with rockets and just hearing a muffled "whump" that wouldn't upset the neighbors. First time I disposed of a charge out in the open, the bang scared the bejesus out of me as I didn't want the neighbors to call the cops. Didn't get in trouble.

Dig hole and bury live charges before igniting them. No noise and with small charges the dirt doesn't move. I've never had a 30 gram charge though and might need to stand clear and put some heavy rocks on top of the buried charge to dispose of it.

Kurt
 
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