mothballs and black rolling smoke

[memo]

Does anyone have a formula for using mothballs to make a black smoke shell.

memo

 

[Arthur]

The moth balls in this case are a source of Naphthalene. Naphthalene is no longer on the market in Europe due to it's suspected health risks. Do remember that Naphthalene naturally sublimes slowly at room temperature so a product containing it will need sealing in a plastic or metal can. Black smokes in commerce have short shelf lives simply because one component sublimes then the excess fuel is no longer in excess and the device turns into a flame pot.

 

see

http://www.thegreenman.me.uk/pfp/smoke.html#Black

Edited February 28, 2018 by Arthur

[MadMat]

I have read that the movie industry uses naphthalene for for the huge orange fireballs that always accompany explosions in movies. I once tried making a cremora with granulated naphthalene mothballs, but I made some serious errors in the construction and it was very underwhelming (It was very early in my pyro days and mistakes are bound to happen.). I never tried another one simply because I didn't have any more naphthalene... until now. Once the weather becomes more hospitable for pyro work, I plan on trying it again.

Edited February 28, 2018 by MadMat

[memo]

i just bought a kilo of mothballs and wanted to give it a go

[Mumbles]

Here are a few formulas I have, besides the Shimizu ones that Arthur linked to. I really cannot vouch for any of these formulas and I'm not sure how well any of these would work as actual stars as I've never really tried. A lot of smoke formulas work a little better when made as pill box stars or perforated inserts filled with granular compositions.

 

 

From PyroSkitz on UKPS. Obtained on 8/25/2010

http://www.pyrosociety.org.uk/forum/topic/5552-interesting-sfx-suitable-for-beginners/

Magnesium powder – 19%

Hexachloroethane – 60%

Napthalene – 21%

From Wonderboy in the APC Chat on 1/20/2014

(in reference to the above formula)

Yeah I have a similar one, calls for Anthracene though. The black smoke I've use was KClO4-Napthalene-sulfur 56-33-11. I just used it in a loose pile in a cup though, so I'm not sure how it'd work pressed in a tube

From FlaMtnBkr on Fireworking. Posted 10/10/2014

I looked some more and found a third one in my notes but looking at them I don't think they are all meant for stars. I believe this first one came from Ken Miller:

Black Smoke

60 KClO3

40 Napthalene

+4% Antimony sulfide

Blend Napthalene and antimony thru 20 mesh screen. Screen chlorate by itself thru 60 or 80 mesh screen. Mix everything 2x thru 20 mesh screen. Mixed with NCL it burns better. Press into tube with 2x ID left empty.

Black Smoke #2

10 KClO3

6 Napthalene

3.5 Antimony sulfide

1 charcoal

1 starch

I would assume the starch could be dextrin or SGRS? It also has a friction sensitive warning.

Black Smoke #3

20-30 KClO3

50 Ammonium chloride

20 Napthalene

0-10 charcoal

[Arthur]

ALL smokes rely entirely on incomplete combustion, it's how they work. The design of the device is critical as well as the design of the compound. Especially with Naphthalene the final airtight (storage) sealing of the device is important too.

Edited March 1, 2018 by Arthur

[MrB]

Purely speculative, but... Would encasing the final product in wax help keeping the naphthalene from evaporating?

[PeteyPyro]

Here are a few formulas I have, besides the Shimizu ones that Arthur linked to. I really cannot vouch for any of these formulas and I'm not sure how well any of these would work as actual stars as I've never really tried. A lot of smoke formulas work a little better when made as pill box stars or perforated inserts filled with granular compositions.

 

 

From PyroSkitz on UKPS. Obtained on 8/25/2010

 

http://www.pyrosociety.org.uk/forum/topic/5552-interesting-sfx-suitable-for-beginners/

 

Magnesium powder 19%

Hexachloroethane 60%

Napthalene 21%

 

 

From Wonderboy in the APC Chat on 1/20/2014

 

(in reference to the above formula)

 

Yeah I have a similar one, calls for Anthracene though. The black smoke I've use was KClO4-Napthalene-sulfur 56-33-11. I just used it in a loose pile in a cup though, so I'm not sure how it'd work pressed in a tube

 

 

From FlaMtnBkr on Fireworking. Posted 10/10/2014

 

I looked some more and found a third one in my notes but looking at them I don't think they are all meant for stars. I believe this first one came from Ken Miller:

 

Black Smoke

 

60 KClO3

40 Napthalene

+4% Antimony sulfide

 

Blend Napthalene and antimony thru 20 mesh screen. Screen chlorate by itself thru 60 or 80 mesh screen. Mix everything 2x thru 20 mesh screen. Mixed with NCL it burns better. Press into tube with 2x ID left empty.

 

Black Smoke #2

10 KClO3

6 Napthalene

3.5 Antimony sulfide

1 charcoal

1 starch

 

I would assume the starch could be dextrin or SGRS? It also has a friction sensitive warning.

 

Black Smoke #3

20-30 KClO3

50 Ammonium chloride

20 Napthalene

0-10 charcoal

That Black Smoke #3 looks like something that I would not want to store or really make, for some reason. Hygroscopic Ammonium chloride + Potassium Chlorate = double displacement to Potassium Chloride + Ammonium Chlorate!

(with an organic fuel to boot.)

Is it just me?

Edited March 1, 2018 by PeteyPyro

[Maserface]

Potassium Chlorate is the least soluble compound between ammonium chloride, potassium chlorate, ammonium chlorate, and potassium chloride. Double displacement only occurs when minimum solubility favors a change.

[memo]

there area couple of formulas that interest me. now the fun begins

[PyroGnome]

On 3/1/2018 at 5:52 AM, MrB said:

Purely speculative, but... Would encasing the final product in wax help keeping the naphthalene from evaporating?

The vapor pressure of napthalene is insanely low and it's a fairly large molecule so encasing it in anything that's either air-tight or only allows gases like oxygen and nitrogen to pass is probably enough to keep it from going anywhere. 

My thought was to dissolve a bunch of scrap styrene in acetone until it's syrupy and use that as a binder to encapsulate the napthalene;  foamed styrene burns to produce oily black smoke on its own so it would probably just contribute more black smoke and only slightly more ignitable gas.

I guess they've been foaming some styrene for insulation with cyclopentane gas which has very low explosive limits in air and can cause asphyxiation if you get a lungful (that's what the warnings on the newer chest freezers are about, it's the insulation rather than the coolant which is kinda confusing) so avoid stuff scrapped from newer coolers or refrigerators.  I don't think they're using it in packing styrofoam where it would raise the flammability too much.

I haven't gotten around to testing this myself but if you're bored and want to try it I see no reason why it wouldn't work.  It's normally supposed to take a couple of months for napthalene to sublime from mixes entirely so an easy test for stability would be making a straight napthalene / styrene cast with no oxidizer.  You could leave it laying around in a closet during the winter like a mothball (and leave a mothball next to it, maybe weigh each one every 2 weeks to see what kind of loss they're doing) without risk of it becoming dangerous.  

Polystyrene has the most favorable carbon / hydrogen ratio of any potential binding agent I could find.  No oxygen like the starches or the majority of polymers or halogens, just C8H8 units.  Napthalene is C10H8 which is only slightly better so a small amount of styrene or even mostly styrene would probably work.  The attractive part about that is that any given person probably has access to nearly infinite amounts of free junk styrene from packing material.  You could probably get enough to last a year by picking a random 100 yard section of highway to clean up gas station soda cups from.  🙂 Rolling this would probably be impossible but cutting could work.  The other option is to make the mess into a soup like go-getters and pour into fused tubes and let them dry then seal the end with a vented cap to prevent flameouts.  Seems more attractive than pressing anything.

Potassium perchlorate will work for napthalene formulas as well (it and chlorate are used more or less interchangably in the anthracene based formulas which showed up a bit later since it's harder to purify from anthracite fractions) if you don't want to use potassium chlorate.  The temperature of combustion is less important for black smokes (see the Mg / Anthracene / HCE(?) versions), they're more about getting the partial combustion right so it doesn't just produce a flame which in turn tends to be more about tube venting.   I've also seen variants that use charcoal to lower the ignition temperature instead of antimony trisulfide which is intrinsically safer if all the napthalene evaporates since charcoal doesn't sensitize chlorate.  

I've also seen older formulas that use asphaultum / gilsonite which costs more than napthalene but is still less than organic smoke dyes.  If you can get dyes cheap, you can also mix the 3 primaries to create black which is what the military seems to be moving towards to get away from HCE but I consider vaporized solvent dyes to be more dangerous than carbon and finding them cheap is the problem unless you're ordering 500kg quantity. 

 

[PyroGnome]

BTW I suspect the 60/40 versions are meant for the "dark flash" salute inserts that just leave a cloud of black smoke behind.  They're only a little light on oxidizer so you'd still get enough black smoke left behind.  There's an oddball formula for brown like this that uses asphaultum and a few other things too.  They need more containment / spiking than a normal salute to get good sound out of.