Flash powder & Castable Plaster Incendiaries

[A-BOMB]

Well I'm needing to make some flash powder for some salutes for a movie thing and I want to use a AL/baruim sulfate flash comp I saw on the PFP, does anyone have any information on it?

Flash #6
Source: rec.pyrotechnics. Post by Patrick Arnold <pcats@cryton.demon.co.uk
Comments: Can be ignited by a fairly low temperature flame, and produces a greenish flash when magnesium is used. Burns very fast, and produces a loud report even in an open container.
Preparation:

Magnesium or Aluminum.............................1
Barium sulfate....................................1

<small>[ December 24, 2002, 12:50 PM: Message edited by: nbk2000 ]</small>

[mr.evil]

I do, i've tried this flash composition but it didn't work. As BaSO4 is an high temperature oxidizer, so you'll need an 'booster' something like thermite or an other composition based on magnesium.

[vulture]

I got the strong suspicion the author meant barium nitrate but mistyped, I can see no other explanation for it being able to ignite from fairly low temperature flame. Of course, if the dude thinks 1400C is a low temperature...

[MacCleod]

I've tried this formula also,using 1000 mesh atomized magnesium,and the results were weak at best.It worked,but was only half as loud (confined) as an equal amount of perchlorate flash.Maybe i'll try using 2 micron black aluminum and see if it works any better.

[binary mz]

on the topic of flash, about 4 months ago i recieved some p. perchlorate and german black head al. powder. i stuck to the 7/3 ratio with very good results. i stopped makin flash for a while, and now about a month later i whip up a batch and it doesnt work. same ratios, nothing...the fuse will burn out going right thru a pile of flash. sometimes the fuse will still be an orange line so i'll shake the coke can (upside down with a pile of flash in that little pit) and i'll see a little flash, but thats it. im thinking thats just al. powder burning. any ideas ? is p. percholrate that hygroscopic ? is there any way i can drive out the moisture ?

[pyro225]

Did a little searching and reading on rec.pyrotechnics via Google ( <a href="http://groups.google.com/groups?hl=en&lr=&ie=ISO-8859-1&q=barium+sulfate+flash++group%3Arec.pyrotechnics&btnG=Google+Search" target="_blank">http://groups.google.com/groups?hl=en&lr=&ie=ISO-8859-1&q=barium+sulfate+flash++group%3Arec.pyrotechnics&btnG=Google+Search</a> ). Found a quite a few references to BaSO4 used as the oxidizer in Flash formulas. Check it out. I've haven't any experience with other than standard 70/30 Flash. Good luck!

[kingspaz]

binary mz, KClO4 isn't hygroscopic. did you measure the Al and KClO4 by mass or volume?

[binary mz]

at one point i used postage scales but got use to makin flash all the time i stopped using them...i just use a teaspoon. weird thing happaned tho, i had a pile of flash that didnt go off by fuse so i put some black powder on top of it hoping that would ignite the flash, well, i had all this in a shot glass..the bp flared up, the flash didnt, but there was an orange ball that stayed in the shot glass...it glowed orange..and it slowly went out..i went to pick up the shot glass and it broke. in to three pieces. the cuts were very clean, so im thinking the heat from the bp broke it ? that ball i was talking about, its a small gray sphere. i'll take some pics soon.

[kingspaz]

well if you used a teaspoon that will be most likely where the error is. measuring things by volume is not accurate or consistent. go back to using the scales. it may take longer and be more hassle but you will have made your flash correct and all other batches following will be equal to performance as there is little room for error using scales.

[inferno]

Binary MZ - not sure why your mix isnt working...but you could try stick a sparkler in as a fuse, that should light it. Are you sure someone didnt swap your KClO4 for salt or something? lol.

[DarkAngel]

Flash must ignite from a normall fuse if it doesn't there is something wrong with the proportions/chemicals.

[mr.evil]

BaSO4(and some other sulfates) are high temperature oxidizers, so it won't lit with just a spark or a 'cold' flame. I guess you need a booster(KMnO4/Fe burns hot!) to start the decomposition of BaSO4.

anyway, i've tested a little of this stuff, and it didn't burn. So next time i will use a better starter mix(booster).

[DarkAngel]

We where talking about his KCLO4/Al flash that didn't ignite not about the BaSO4 comp.
I know XSO4 comps need high temperature in order to ignite.

I made a good working comp. several times using normall CaSO4 (plaster) AL and S.

What are your ratio's for the BaSO4 comp.?

[DarkAngel]

I made the CaSO4 composition again and record it.
<a href="http://entersection1.virtualave.net/Pictures/CaSO4_FLASH_01.mpg" target="_blank">Download Movie</a>

Here are some shots from the movie:
<img src="http://entersection1.virtualave.net/Pictures/CaSO4_FLASH_01.JPG" alt=" - " /> <img src="http://entersection1.virtualave.net/Pictures/CaSO4_FLASH_02.JPG" alt=" - " />
<img src="http://entersection1.virtualave.net/Pictures/CaSO4_FLASH_03.JPG" alt=" - " /> <img src="http://entersection1.virtualave.net/Pictures/CaSO4_FLASH_04.JPG" alt=" - " />
<img src="http://entersection1.virtualave.net/Pictures/CaSO4_FLASH_05.JPG" alt=" - " />
I used a broken firecracker as an ignitor, and as you can see there is almost no residue left.

<small>[ August 23, 2002, 11:19 AM: Message edited by: DarkAngel ]</small>

[Kdogg]

I hope noone minds if I trail a little off topic, but im getting worried. Ive been reading around about Potassium Chlorate flash going off at any given moment for no reason.
I have around 25 m-80s made with it & 600 mesh German dark, I do not want to light them right now. Around next July 4th I planned on saving them for. Its a long time I know, but do I have to worry about them going off? Right now I have them in a fireproof safe, so the damage would be minimal if they went off, I dont think it will take the internal pressure though. Will they stay in there without going off?
Also what is it that sets them off for no reason, so I can steer clear of it. I know static, & sulphur. Thats another thing the sulphur thats in the fuse wont affect it much will it. I hope I am just bein too paranoid & can keep them without worrying. Thanks in advance.

Edit: I did have that in paragraphs, what happened??

<small>[ August 24, 2002, 12:00 AM: Message edited by: Kdogg ]</small>

[mr.evil]

DarkAngel,
Very cool you posted that pics/Movie.

i've tried the CaSO4 flash a few minutes ago(with the same Al as yours, and sulfer), but it didn't burn. What was the composition you used? Thanks.

edit: typo

[DarkAngel]

It's from the PFP Database.
CaSO4 57.8% S 1% Al 40.9% Caster oil 0.3%
I didn't use Castor oil and i even think that you can leave out the sulfer if you don't have it.

[Anthony]

I'd imagine that the sulphur helps the mixture ignite at lower temperatures.

I see no reason why KClO3/Al should spontaneously ignite, although a small amount of sodium bicarbonate in the mix might be wise if you want to store them.

I don't think keeping them in a safe is at all wise. Should the fire crackers go off by themselves, they present very little fire risk and would explode relatively harmlessly in the open. By putting them in a safe you've effectively made a bomb which would be considerably more dangerous.

I'd keep them in a cardboard box somewhere dry and preferably out of your house. Personally I wouldn't store them for that amount of time, it's not like you've got much invested in 25 crackers, you can always make more. They not only present a safety hazard, but a legal one too if they're found.

I'm not sure about the compatibility of BP fuse and chlorate mixes. When I used to make NaClO3/sugar crackers, I'd use non-BP based fuse just in case. I guess you could put a coating of NC laqueer or other binder over the cut end of the fuse to provide a physical barrier between the chlorate and the sulphur.

[kingspaz]

the fuse problem can easily be solved by using dextrinated sulphurless BP for the fuse. i use this very fuse and its never let me down yet :)

[Bubba]

Below cut from my post under "Flashbang" thread:

I have the Paladin Press book on makeing Flashbangs.

Shows the M116 Grenade "simulator" filler is:
40% AL powder
30% Potassium Perchlorate
30% Barium Nitrate

They call it "Photoflash"

For a "Expedient" Flash Bang they recommend:
(below amounts are by weight)
20% AL shavings
20% Magnesium shavings
30% Potassium Perchlorate
30% Barium Nitrate

[Macgyver]

One flash composition I've had pretty good luck with is:

60% Potassium Perchlorate
20% Sulfur
20% Atomized Aluninium Powder (&lt;25 uM)

And always use perchlorates instead of chlorates for flash compositions, and if you want to be even safer, you can skip the sulfur and go with 67% perchlorate and 33% aluminium dust.

It is a bit less powerfull without sulfur, but still fun...

[green beret]

I did a quick search on google, and calcium sulfate can be bought as gypsum which is hydrated calcium sulfate, will the hydrated type(gypsum) work in the CaS04 flash comp?

<small>[ December 14, 2002, 02:55 AM: Message edited by: green beret ]</small>

[nbk2000]

Plaster of Paris burns very well with aluminium too. Cast a 3" cube of it (forgot the ratios) and the whole thing burned to nothing in just a few seconds. Try using plaster as a loose powder and see how that burns.

[green beret]

That sounds good, I'll have to get some plaster of paris. Also when you said to cast a cube of it, do you mean using water? If so, dosent that react with the aluminium to produce hydrogen gas? Sorry if I missed something, I'm a little tired. I am estimating the ratio of al. to plaster would be around 80 to 20? I will try some anyway. Do you think that the hydrated CaS04 will work in the above mention flash comp?

[nbk2000]

I used the ratios described in one of the black books for making a castable incendiary. Don't remember what they were, but it's easy enough to find.

Yes, I used water to make it castable. I then cooked it in an oven for 12 hours to dry it.

Being in a powdered state, all light and fluffy, I imagine it'll burn amazingly fast.

But it was a holy pain to get burning. I had sugar/chlorate on top of Zn/S, and even then it didn't light the first time. But that was cast, powders are much easier. Use a little magnesium, if you have it, to get the fire started.

[Mr Cool]

I bet about three sparklers together in the cast mix would set it off, or if you have some sort of press (hydraulic, vice, etc) you could press the composition, and press a layer of some easier to ignite Al composition on top (eg the stuff from sparklers), then this could be ignited however you want.
Or cast the composition with water and dry it as described by NBK, then drill a hole in it down to the middle, and press your igniter charge into this. This way you wouldn't need a press, since the low cross sectional area of the igniter charge would mean that a relatively small force will give enough pressure for it to be pressed solid.
Magnesium sulphate might work better, since the cation is inert weight and Mg weighs less than the same amount of Ca, so you should get more oxidising power per gram. It would probably be harder to ignite though (Mg compounds have higher lattice enthalpies than those of Ca), but it wouldn't cost much to try (epsom salts / sulphate of magnesia from a normal garden centre is about £3/kg).

[mr.evil]

i bought 500 grams MgSO4 last summer in Brussels, it is really cheap but note that MgSO4 is extremely hygroscopic so buy alot as it contains tons of water...

anyway, i've tried CuSO4/Mg but it didn't burn.. Tonight i will do more tests with it and try to light it with soms thermite(i use CuO/Al).

[vulture]

Did anybody ever tried Titanium flashpowders? Not just flashpowder with Ti added for sparks, but as main fuel?
It's supposed to be really powerful, owning to the very high burning temperature of Ti, that has the second highest temperature after Zirconium.

[nbk2000]

Titanium has been investigated as a replacement for zirconium as an incendiary filler in weapons. It's also cheaper.

[photonic]

I've been trying to make some flash powder for a while now but obtaining the ingredients has been a problem. Is there any local source for things like potassium perchlorate other ingredients? I can't order online because I don't have a credit card. I seem to remember seeing calcium sulfate(maybe it was sulfite?) as a vitamin at Eckerds. Is CaSO4 the plaster of paris? Actually, it's potassium perchlorate i've been searching for. Thanks.

<small>[ December 15, 2002, 01:16 AM: Message edited by: photonic ]</small>

[EP]

You could try eBay, there are often chems like KClO4 for sale there. I was just checking today and you could get 5kg for $80 I think... If you don't have a CC you can use a money order if the seller accepts that payment form, but if you can't order from a supplier or from eBay you're pretty much screwed.

You can use United Nuclear if you get desperate, they have bad prices and sell 8oz max per chem each order, but they do take CC, MO, check and even cash.

[Al Nobel]

Today i produced some flash (KNO3+Al dust,KNO3+Al dust+S).I used paint grade Al,300 mesh Al-dust from a chemical supplier (in different batches).The KNO3 i used was pure as well as the sulfur.I grinded the KNO3 in a coffee grinder for a while till it was only dust.The incredients were mixed well and the proportions were ok (i used a electrical scale).When i tried to ingnite it with a fuse nothing happend.I dont have BP at the moment to place it on top of the batch (dont know if a fuse is strong enough to ingnite the batch).Any suggestions why it failed?

[kingspaz]

i think that paint grade Al you used is spherical and so has a relatively small surface area for burning to occur on. powder in this form is much more unreactive than the flake Al. this Al will only be of use for thermite comps. i've tried it in a chlorate flash and it didn't work either. although i finally got it lit with a sparkler and it burnt very slow and very bright.

<small>[ December 17, 2002, 05:44 PM: Message edited by: kingspaz ]</small>

[Al Nobel]

Thanks for help kingspaz .My problem now is that i dont know where to get german black Al or other usufull Al for flash.I searched a lot in the past but could only get paint grade Al or Al dust from a chemical supplier.I´ve tried to find information in the forum archives but without success.I´d be happy if any other german forum member could tell me where to get it here.

[Arkangel]

Al, if you mail me, I have some suggestions for you

[Jumala]

This auktion ends yesterday. But he has more black AL powder for somewhat like 20 Euro/Kg.
I got mine there.

<a href="http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=1980774990&category=9773" target="_blank">http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=1980774990&category=9773</a>

<small>[ December 17, 2002, 09:32 PM: Message edited by: Jumala ]</small>

[Al Nobel]

Thanx for help.I managed to get 500g Al-powder which works fine for flash.Now i have a question concerning KNO3/Al flash.I´ve read in the archives that this mix may spontainosely ingnite.Will this only happen ,when i let it lie around and allow the KNO3 to absorb moisture or is it a general disadvantadge of this mix? I´ve already tested this mix and it works fine. Now i plan to use it for my sylvester crackers (in small amounts).Do i have to fear my crackers to go off with no reason when i use a waterproof casing? Sorry for my english

[Sparky]

Aluminum and potassium nitrate can spontaneously react in alkaline conditions. I've never seen it happen though. The usual solution is to add about 1 or 2 percent boric acid. When a friend of mine tried potassium nitrate/aluminum without sulfur flash he had no luck. What formula are you using?

[carbonated]

Is the CaSO4 anhydrous?

[kingspaz]

carbonated, make it clear as to what you are refering to. the topic has moved towards KNO₃/flash. now it looks like you are asking whether the CaSO₄ in tha flash being discussed a couple of posts above is anhydrous. of course there isn't any in the flash a couple of posts above. i'll stop rambling, you'll think about what you are saying before you post.

<small>[ December 19, 2002, 05:13 PM: Message edited by: kingspaz ]</small>

[Al Nobel]

I used two different formulas: 6 parts KNO3,3 parts Al,1 part sulfur and 7 parts KNO3,3 parts Al.Both worked (the first one a little bit better then the second one).Any suggestions what i could use instead of boric acid?

[kingspaz]

well if its dangerous in alkaline environment then the sulphur should act as a guard against this since sulphur oxides present will remove any OH^-.

[carbonated]

Your right kingspaz.

Yes, I meant the CaSO4/Al/S (and castor oil) flash powder. Is it better to have the CaSO4 anhydrous?

[nbk2000]

Of course the plaster powder is anhydrous. It's because of the absorbtion of water that it solidifies into hydrated plaster.

[Sparky]

Donald Harmann just posted a great article on sulphates in pyrotechnics, on rec.pyrotechnics. I hope he doesn't mind me posting it here. For those of you who don't read rec.pyrotechnics here it is. I would link to it but for some reason it isn't currently archived by google. BTW, why would you not want to use boric acid? It is easy to get at a pharmacy, no questions. Mike Swisher recommends dissolving the boric acid in water first to evenly distribute it throughout the composition. I think this applies more to stars using dextrin as a binder than loose flash like you are talking about.

As a bonus it makes a nice green flame when mixed with methanol.

Subject:
Re: Barium Sulfate/Aluminium Flash Powder (ignition)
Date:
Sun, 22 Dec 2002 01:27:38 GMT
From:
"donald j haarmann" &lt;donald-haarmann@worldnet.att.net&gt;
Organization:
AT&T Worldnet
Newsgroups:
rec.pyrotechnics
References:
1 , 2 , 3 , 4 , 5

"news" &lt;TEMP@hotmail.com

&gt; If that was to say 'plonk', ie - to add Rich to your 'ignore' file, bad
&gt; choice. He's a pretty darn good source of info, and his statement was more
&gt; than justified.
&gt;
&gt; In regards to your comp, yes, I do recall having heard of comps w/ Ba SO4
&gt; before, though they are by no means common. Try searching google.com for
&gt; key words.
&gt; Sulfates are usually not preferred because they really like their oxygen.
&gt; There are many compounds which are far more generous w/ their O
&gt; atoms/Oxidation state.
&gt;
&gt; Mark D.
&gt;
&gt; "Matriarc" &lt;stalin4772b@hotmail.com&gt; wrote in message
&gt; news:aea0a10a.0212201556.2c8b5a8d@posting.google.c om...
&gt; &gt; bump

---------------
PGI Bulletin No. 46, March, 1985
THE FEW, THE PROUD, THE SULFATES
by
Donald J Haarmann

[Having lost the original file! This was scanned in. And you
know what that means!!]

Most sulfates are not water soluble, are geologically stable
and can be easily and cheaply obtained by mining, rather
than having to be produced through complicated and expensive
chemical processing. Therefore sulfates pass the first test
for possible inclusion in any pyro formula; they are
inexpensive. Indeed native sulfates such as barite (BaSO4)
and celestite (SrSO4) are the starting materials for other
barium and strontium compounds used in fireworks.

Sulfates certainly appear attractive because their oxygen
content compares favorably with that of metal chlorates,
perchlorates and nitrates, as Table 1 illustrates. Also a
comparison of the heat evolved from reaction of aluminum and
various oxidizing agents again shows that sulfates compare
favorably with more familiar pyrotechnic oxidizers. (See
Table 2.)

Table 1
Percent oxygen contained (percent by weight) for various
pyrotechnic oxidizers and sulfates, for the anhydrous
compound.

Nitrate Chlorate Perchlorate Sulfate
Ammonium 0.60 0.47 0.54 0.48
Barium 0.37 0.32 0.38 0.27
Calcium 0.58 0.46 0.41 0.47
Copper 0.51 0.42 0.49 0.40
Gadolinium 0.42 0.35 0.42 0.32
Lithium 0.69 0.53 0.60 0.58
Magnesium 0.65 0.50 0.57 0.53
Potassium 0.47 0.39 0.46 0.37
Sodium 0.56 0.45 0.52 0.45
Strontium 0.45 0.38 0.45 0.47

Table 2
Heat produced (cal/g) from a mixture of an oxidizer or
sulfate with aluminum. Values from AMCP 706-185(1967) and/or
Vasilev (1973) (*).

Sodium perchlorate 2,600
Lead nitrate 1,500
Sodium chlorate 2,500
Barium nitrate 1,400
Potassium perchlorate 2,400
Cu sulfate 1,400/1,560*
Potassium chlorate 2,200
Ca sulfate 1,300/1,470*
Sodium nitrate 1,800
Na sulfate 1,200/1,360*
Potassium nitrate 1,800
K sulfate 1,200/1,180*
Lithium sulfate 1,620*
Barium sulfate 900/910*
Magnesium sulfate 1,610*
Lead sulfate 800
Ammonium nitrate 1,600

However, low cost is not the only criteria for selecting
oxidizers for use in fireworks compositions. A quick check
of Table 1 reveals several oxidizers with high oxygen
content, for instance, calcium, sodium, and ammonium
nitrates, sodium chlorate, and magnesium perchlorate.
However, of these only sodium nitrate has found use, albeit
limited primarily to military pyrotechnics. All of these
compounds are hygroscopic and therefore unusable in the real
world. In fact, magnesium perchlorate is used as a drying
agent under the trade name of "Anhydrone".

There can be no doubt that the largest problem concerning
the use of sulfates as oxidizing agents is their waters of
hydration, for example:

Na2SO4-10H2O and CuSO4-5H2O. Although the ten extra oxygen
atoms in sodium sulfate raise its total oxygen content from
45% to 70%, this extra oxygen contained in the waters of
hydration is not available for productive work. In truth it
only gets in the way, since a large amount of heat is
required to first remove the water of hydration from a
composition's outer surface before the ignition temperature
can be reached. Then once the reaction becomes self
sustaining, even more heat, produced by a burning star for
instance, will be removed from the reaction in the form of
vaporized water. (It should be noted that the latent heat of
vaporization for water is 540 calories per gram of water at
100° C. This value represents heat that must be supplied by
the pyrotechnic reaction to change water at 100° C into
steam at 100° C.) There is also the possibility, in
magnesium containing compounds, of the water vapor reacting
with the magnesium forming hydrogen and magnesium oxide,
effectively removing a large amount of fuel, with little
gain in heat. In the case of sodium sulfate decahydrate,
where 56% of each molecule is water, 31,920 calories of heat
would have to be supplied simply to remove all the water of
hydration in the form of steam from each 100 grams of
sulfate. For example, in a composition using potassium
perchlorate as the oxidizer and aluminum as the fuel, 13.3
grams of aluminum and potassium perchlorate would be needed
just to remove the water from each 100 grams of sodium
sulfate decahydrate, before any useful work (heat and/or
light) would be produced!

As a further complication, the temperature at which waters
of hydration are liberated varies from sulfate to sulfate,
e.g., sodium sulfate decahydrate loses all its water at 100°
C while manganese sulfate monohydrate does not lose all its
water until the temperature reaches 400-450° C! And to
really complicate things, manganese(II)sulfate can exist as
either mono, tri-, tetra, penta, hexa, or heptahydrate!
Although the tetrahydrate is the most common form.

However, US Patent 2,885,277 claims to make use of the
waters of hydration in magnesium sulfate heptahydrate,
MgSO4-7H2O (Epsom salts), to produce hydrogen gas when the
sulfate is reacted with magnesium. It is further claimed
that this combination will function as either a torch or a
salute. It would be well to note that Ellern (1968, p. 272)
expresses doubt concerning the safety and utility of such
mixtures.

The use of sulfates as oxidizers suffers from yet another
problem. As Dr. Conkling (in press) has pointed out "In
pyrotechnics, the solid liquid transition appears to be of
considerable importance in initiating a self propagating
reaction. The oxidizing agent is frequently the key
component in such mixtures, and a ranking of common
oxidizers by increasing melting point bears a striking
resemblance to the reactivity sequence for these materials."
Unfortunately the melting point of most sulfates is much
higher than either chlorates, perchlorates or nitrates. Only
four sulfates (manganese, copper, zirconium and iron) have
melting points below that of barium nitrate, and these four
are well hydrated (tetra or penta). Melting points are
summarized in Table 3.

Table 3
Melting point for various anhydrous oxidizers and sulfates.
Values are from the CRC Handbook. d decomposes, sd slight
decomposition.

Copper perchlorate 82
Ag perchlorate 486
Iron perchlorate &gt;100d
Thorium nitrate 500
Strontium chlorate 120d
Th perchlorate 501
Lithium chlorate 128
Ba perchlorate 505
Scandium nitrate 150
Sr nitrate 570
Manganese(III) sulfate 160d
Ba nitrate 592d
Americium nitrate 170
Zn sulfate 600
Copper sulfate 200sd 650d
Th(I) sulfate 632
Silver chlorate 230
Silver sulfate 652
Lead chlorate 230
Mn(II) sulfate 700
Lithium perchlorate 236
Lithium sulfate 845
Sodium chlorate 248
Nickel sulfate 848
Magnesium perchlorate 251d
Sodium sulfate 884
Lithium nitrate 264
Ytterbium(III) sulfate 900
Calcium perchlorate 270
Yttrium sulfate 1000
Sodium nitrate 307
Cesium sulfate 1010d
Rubidium nitrate 310
Rubidium sulfate 1060d
Potassium nitrate 334d
Potassium sulfate 1069
Calcium chlorate 340
Samarium sulfate (basic) 1100
Potassium chlorate 356
Magnesium sulfate 1124d
Potassium perchlorate 400d
Lanthanum sulfate 1150
Zirconium sulfate 410d
sulfate 1170d
Cesium nitrate 414
Calcium sulfate 1450
Barium chlorate 414
Barium sulfate 1480
Iron sulfate 480d
Sr sulfate 1605d
Sodium perchlorate 482

It is evident that getting compositions based on sulfates as
oxidizers to ignite while not impossible ... is not going to
be easy. There can be no doubt that it is going to take an
extremely hot ignition source!

Copper sulfate with its low melting point looks like a prime
candidate but again, the water of hydration is a problem.
Exposed to moist air, CuSO4 becomes CuSO4-H2O, and when
wetted, CuSO4-5H2O. Also, because copper sulfate is water
soluble, it is seldom found in native form (chalcanthite).
Therefore it is manufactured from copper metal and sulfuric
acid, and as a result fails the first test, it is not cheap.
It is also not safe with chlorates.

Although certainly attracting because of their low cost
oxygen content, sulfates have for the most part, not been
employed as oxidizing agents. However, them have found their
niche in strobe formulas.

Vander Horck (1974) reported on several formulas using
calcium and copper sulfates demonstrated to him by Bob
Winokur who later (Winokur, 1974) made additional comments
about them. Further Dr. Shimizu (1981) presents several
strobe ("twinkler") formulas using sulfates, i.e.,
strontium, barium, sodium and calcium. Advantage is taken of
the great difficulty of igniting and then sustaining
ignition in sulfate based compositions. Therefore flashes of
light are produced each time the sulfate reaches its melting
point or decomposition temperature, burning commences and
shortly thereafter extinguishes only to repeat, producing
the strobe light effect.

Sulfates have long been used in color flame compositions
more for their metal than oxygen content. However, for the
most part, the color produced by sulfate based compositions
not containing metal fuels such as aluminum or magnesium,
will be found to be less than satisfactory, since only metal
fuels are capable of producing the high temperatures
necessary to melt or decompose most sulfates. The use of
various sulfates is detailed below:

Copper sulfate: In older literature, e.g. Kentish (1878)
compositions for blue flames can be found using copper
sulfate and potassium chlorate, where the copper ion is used
to produce the blue color. THIS COMBINATION IS DANGEROUS.
Safer and more effective blue formulations are available.

Barium sulfate: Troy Fish (1981) recommends the use of
barium sulfate in parlon bound green stars. He notes that as
a result of barium sulfate's extreme insolubility (0.000413
grams per 100 ml of boiling water!), it is one of the few
nontoxic barium compounds. I have been able to locate only
seven formulas using barium sulfate, and all seven use
either magnesium, aluminum or magnalium.

Calcium sulfate: Despite the many obstacles noted above,
calcium sulfate hemihydrate (plaster of Paris) [CaSO4-
1/2H2O] has been used as an oxidizer in fireworks and
pyrotechnics: In combination with sodium and barium nitrate
in white light compositions (Ellern, 1968, formulas 36, 37
and 38), as an incendiary when combined with aluminum (US
Patent 2,424,937, Vol. 3 of the "Black Book", 1982), or
aluminum and magnesium sulfate (US Patent 4,381,207), and
when compounded with aluminum, Teflon, and sulfur (US Patent
4,349,396) as a metal cutting torch.

Calcium sulfate combined with either aluminum or magnesium
has been suggested as a "flash report" mixture! (Sanford,
1974)

This sulfate is found in pink tableau fire or star
compositions using potassium perchlorate as the oxidizing
agent. Weingart (1947) has the only modern for
mula I have been able to locate that uses calcium sulfate
without either aluminum, magnesium or magnalium.

Potassium sulfate: The Technico Chemical Receipt Book 1896
long ago recommended the use of potassium sulfate in blue
compositions. There is only one modern formula using
potassium sulfate, Dr. Shimizu's white "twinkler" using
magnalium as the metal fuel.

Strontium sulfate: This sulfate had long ago been used in
the production of red or purple flames. However, there are
no formulas using strontium sulfate in Lancaster, Ellern or
Weingart. There are however, three "twinkler" formulas in
Shimizu using strontium sulfate. All three contain
magnalium.

Sodium sulfate: I have been able to locate only four
formulas using sodium sulfate, all by Dr. Shimizu, who uses
sodium sulfate in combination with magnalium for yellow
strobe stars.

Manganese sulfate: Perhaps the most interesting use of
sulfate is the addition of manganese sulfate (MnSO4 H2O) to
aluminum sodium nitrate flare compositions. Farnell et
al.(1972) discovered that this compound alters "the
decomposition of sodium nitrate to form oxides of nitrogen
rather than its normal decomposition products of nitrogen
and oxygen." This change results in a 55% decrease in
burning rate, a 155% increase in luminous output, and a 466%
increase in luminous efficiency!

Although not a mainstays of the fireworks trade, sulfates
have found employment along with the proverbial kitchen
sink, used frying pans, oil of spike and philosopher's
wool!!!

Literature cited

AMCP 706
185, 1967, Engineering Design Handbook, Military
Pyrotechnics Series
Part 1; Theory and Application. NTIS AD 817071.

Black Book, 1982, Improvised Munitions Black Book, Vol. 3.
Desert Publications.

Conkling, J., (in press), The Chemistry of Pyrotechnics and
Explosives: Basic Principles and Theory. Marcel Dekker, New
York.

CRC Handbook of Chemistry and Physics, 1981, 62nd edition.

Ellern, H., 1968, Military and Civilian Pyrotechnics.
Chemical Publishing Inc., NY.

Fish, T., 1981, Green and other colored flame metal fuel
compositions using parlor. Pyrotechnica Vll, pp. 25
37.

Farnell, Westerdahl and Taylor, 1972, The Influence of
Transition Metal Compounds on the Aluminum
Sodium Nitrate Reaction. Third International Pyrotechnics
Seminar.

Kentish, T., 1887, The Pyrotechnists Treasury, The Complete
Art of Fire
Making. Chatto and Windus, London.

Sanford, R., 1974, Plaster of Paris flash powders, American
Pyrotechnist Fireworks News, p. 527.

The Technico Chemical Receipt Book 1896.

Merck Index, 1983, The Merck Index: An Encyclopedia of
Chemicals, Drugs, and Biologicals. Merck and Co., 10th
edition.

Shimizu, T., 1981, Fireworks: The Art, Science, and
Technique. Maruzen Publishing Co.

US Patent 2,424,937, July 1947, Incendiary Composition.

US Patent 2,885,277, May 1959, Hydrogen Gas Generating
Propellant Compositions.

US Patent 4,349,396, September 1982, Metal
Cutting Pyrotechnic Composition.

US Patent 4,381,207, April 1983, Pyrotechnic Composition.

Valsilev, A.A., et al., 1973, Combustion of mixtures of
metal sulfates with magnesium or aluminum. Translated from
Russian. NTIS AD 785988, 5 pp.

Vander Horck, M.P., 1974, Unconventional star compositions
demonstrated. American Pyrotechnist Fireworks News, 7(4),
issue no. 76, p. 506.

Weingart, G. W., 1947, Pyrotechnics. Chemical Publishing
Co., NY, pages 61 and 134.

Winokur, R., 1974, More on unconventional stars. American
Pyrotechnist Fireworks News, 7(5), issue no. 77, p. 516.

--
donald j haarmann — colophon

[Anthony]

Adding water (with boric acid dissolved) to finely divided metal powders may not be strictly safe. IMO, it would be better to use a solvent such as alcohol or acetone.

[Mr Cool]

Just thought I'd post the results of my messings with CaSO4/Al mixtures today.
The ratio I used was 6:4 (CaSO4:Al). I used "paint grade" Al, which is spherical and about 300 mesh. I made up 100g of the mixture. I tested 5g of the loose powder unconfined, a sparkler ignited it with ease. It burnt faster than unconfined green meal powder, but did not burn completely.
The remaining 95g was wetted and put into a cardboard tube about 2" in diameter. When hard, the cardboard was ripped off and the cylinder was neatened up a it with a knife. After scraping off all the little messy bits, and drilling a hole for the igniter, I had 8g of hydrated powder/grains. This could also be lit with a sparkler despite being noticably moist, it burnt slowly but completely (because the slag was not thrown out, it helped it to stay alight).
The rest of the cylinder is now drying in the oven at gas mark 1, to be lit tomorrow. I believe that having the igniter charge in a hole in the main charge will help ensure that it stays lit, as it will help to contain the slag. Also it should be helped by the fact that a big block will burn much more slowly than a loose powder.
I might try to photograph it while it's burning, if the camera can handle it. I couldn't see properly for a few minutes after the little tests...

[nbk2000]

If it burns anything like mine did, you'd better have your back to it 'cause it'll be many times brighter than day. I made the mistake at looking at mine while there was a 5' high flame of burning aluminum. Left me blinded for a bit afterwards, like stepping into the day after being in the dark.

In one of the patents, mention was made of using 1% by weight of glycerine to improve the hardness and density of the plaster/Al mix. Might want to try that next time.

Use the hottest burning igniter you can. Sugar/chlorate didn't do the trick, and zinc/sulfur took a bit of time. Crushed up sparkler powder should work well.

I'd also advise against being near it while it's burning. These mixes are known to explode from trapped water pockets flashing into steam, throwing slag and shit around. <img border="0" title="" alt="[Eek!]" src="eek.gif" />

<small>[ December 22, 2002, 01:16 PM: Message edited by: nbk2000 ]</small>

[Mr Cool]

:D :D :D
It works! The cylinder had a burn time of about 30 seconds after drying in the oven at gas mark 1 for two hours, it was almost totally dry (weighed 90g).
I did manage to get a photo, which I'll put on my site and then give you a link. The camera didn't like it though, it looks like it's dark on the photo but that's just the camera protecting itself, it was still easily light enough to see!
I also got a photo of the STEEL that it burnt through. It's very thin steel, but I was still quite impressed.
I'll upload them now, and give you a link a little bit later on...

[Mr Cool]

Damn, Homestead aren't letting me log in to my account. I'll try again later.

Edit - Try these:

<a href="http://www.boomspeed.com/mrcool/CaSO4-Al.jpg" target="_blank">http://www.boomspeed.com/mrcool/CaSO4-Al.jpg</a>
<a href="http://www.boomspeed.com/mrcool/CaSO4-Al-Damage.jpg" target="_blank">http://www.boomspeed.com/mrcool/CaSO4-Al-Damage.jpg</a>

<small>[ December 23, 2002, 07:57 AM: Message edited by: Mr Cool ]</small>

[Haggis]

Not to be horribly questionable on the first post, but did you get that from the case of some electronic thing? Most cases I've encountered are all aluminum. Oh well, good damage picture anyway.

<small>[ December 23, 2002, 12:15 PM: Message edited by: Haggis ]</small>

[Mr Cool]

It was something electronic, I don't know what though. It's definitely a steel of some kind, or a crazy new magnetic form of aluminium :rolleyes:

[Anthony]

Hey, I just found a use for that tin of spherical Al powder! I think we've even got a bag of plaster laying around somewhere too... Thanks MrC :D

[kingspaz]

hey, i've just thought, why not cast a cylinder of cast thermite with a 1cm hole through the centre? if you set that off then the hole through the middle would direct a fair bit more slag/iron down to the bottom and so landing on the target. it would also ignite itself on the way down but that would just make room for more iron to flow down from the top.
comments?

<small>[ December 23, 2002, 05:02 PM: Message edited by: kingspaz ]</small>

[Mr Cool]

Sounds like it'd work I think, although the hole may need to be bigger to get more molten crap in contact with the target.

Right, tomorrow's testing will be to add silicon carbide to the CaSO4/Al mixture, maybe replacing about half of the Al. Just because I have a lot around that isn't doing anything. I know SiC burns hot with KMnO4, and isn't too hard to ignite either.
It might work, it might not. I'll just have to see what happens.

[Arkangel]

At last! Something useful to do with the 5kg of spherical Al that I've had sitting around for a year!!!!!! :)

Edit: Kingspaz, I like the idea of the hole in the centre, although the problem might be lighting it from the centre. I guess if you designed it like a thick walled, inverted cup, with the igniter in the centre of the "base", that should work?

<small>[ December 23, 2002, 07:37 PM: Message edited by: Arkangel ]</small>

[kingspaz]

yes. somthing with thick walls was in my head. maybe if you cast it with the hole going almost the whole way to the top but leaving say a 1cm wall between the top and where the hole begins. then drill above the hole a little way and put a starter comp on that. i have 300-400g of thermite lying round so i'll give it a go if i find a suitable target on my travels.

[nbk2000]

I've been thinking of how you can make these into "burn bars" for cutting crawlholes into things. It's nice to be able to burn a hole, but nicer to be able to make a hole big enough to crawl through.

If you made "pellets" by casting the mix in short lengths of cardboard tubing, you could make a holder for the pellets. The holder would allow you to hold the burning pellet on a target, as well as keep a constant supply of fresh pellets ready.

The holder would have several pellets in a row, the burning out of the front most pellet causing the ignition of the next.

When you were done cutting the target, you simply discard the burning pellet, keeping the rest ready for the next task.

In making the pellets, the important task would be making it so that the pellet doesn't burn through the sides before the end, or vice versa. You'd want the pellet to burn to the circumferance just as it burns through the ass end. This way there's no pellet remains to block the next pellet, nor premature ignition.

If you don't use a central core, you could cast them as solid rods. Though I doubt these would be nearly as effective because a central core provides jet action to blow slag out of the way.

A central wire core could provide strength so the rod doesn't break under its own weight. Cut notches every few inches would allow you to break the rod, and thus end the burning, without having to use up the entire bar.

[Mr Cool]

The SiC version is almost ready, just another 9g of water to bake off. I'll get some pics for ya'll (I added some coarse Al too for a nice sparkly effect :) ).
I used the 60:40 ratio again (I tried 65:35, but it didn't seem to be as good, although there was still metallic Al left behind), except that half the Al was replaced by SiC. Half the SiC used was very fine, 600 or 800 mesh IIRC, and half was coarser, like glitter. I would've used all fine stuff, but didn't have enough.
We'll just have to wait and see if it works.
Unfortunately I don't have any iron oxide at the moment, I wanted to try a half thermite, half plaster/Al incendiary sort of mixture. Time to go to the ceramics place, I think...
What else could you add that burns good, or would help it burn?

[nbk2000]

Whoa! Easy there cowboy. <img border="0" title="" alt="[Wink]" src="wink.gif" />

Perfect the plaster mix first, before trying variations. It's only after having perfected one formula that you'll be able to determine what effect variations have.

[Mr Cool]

Oh, but I'm bored of that mixture now!
:)

[nbk2000]

Bored?!

You've only done it, what, twice? Maybe three times?

Experimented with different component ratios, burn rate moderators, inhibitors, core sizes, and all the other ways to alter it?

Anyways, it's your shit, do with it want you will. I'm just suggesting you work on a reliable device before expanding out on tangents.

[Mr Cool]

The one with SiC didn't even burn! CaSO4 probably just isn't a good enough oxidiser for it :(.

I'm happy with the 60:40 mixture when just using CaSO4 and Al, I've tried other mixtures, on both sides of that ratio, and certainly none of them actually seemed any better (but it's hard to tell, you can't judge it by light output and the burn times have been pretty constant when you allow for variations in manufacture). I still got metallic Al left behind, even with 80:20! I can't believe adding any more plaster would be advantageous though.

I'm not using my flake Al for this, my supply of that is more limited and I want it for flash. I might try a little one with it to see what it's like, but I'm mainly going to stick with spherical to keep it more OTC.

So although the pure CaSO4/Al mixture could possibly be tweaked a bit more, I don't think it's going to get significantly better than the 60:40 ratio, and I don't really have any very scientific ways of comparing them.

[Sparky]

I think you might be getting left over aluminum because it's not mixed well enough. I know with black powder and kno3/sucrose mixtures if they are not mixed well then lots of residue can be left. Take the same mix and ball mill for a bit it and it is fine.

[Mr Cool]

Please, credit me with some intelligence Sparky!
I know enough to know how to mix things well <img border="0" title="" alt="[Wink]" src="wink.gif" /> .
I think it might be the spherical Al not burning fast enough maybe?

Anyway, I have another lovely picture:

<a href="http://www.boomspeed.com/mrcool/CaSO4-Al-plastic.jpg" target="_blank">http://www.boomspeed.com/mrcool/CaSO4-Al-plastic.jpg</a>

This was the result of mixing in a few chunks of plastic, in the hope that the molten plastic would act a bit like napalm. It seemed to work, the plastic went all over the wooden board it was on and continued burning for a little while.
It was 100g of CaSO4/Al, with just under 15g of plastic (roughly 1cm pieces).

P.S. - I tried to make one with flake Al, but made the mistake of mixing the plaster and Al before adding water! The flake Al coated the water's surface (looks like mercury), and prevented me from mixing it in. If you try it with flake, you'll probably need to mix the plaster with water first, then quickly knead in the Al.

<small>[ December 25, 2002, 12:11 PM: Message edited by: Mr Cool ]</small>

[DarkAngel]

I already thought it whas so strange that nobody seem to face problems when they ad water to there AL powder.
When you use flake AL use water and/or only a solvent (Ethanol,Naptha both worked)to prevent the mixing problem.

Im drying a 200gr AL/CaSO4 charge now afcourse a movie will be made but you have to wait till next year (next week,duh).

<small>[ December 25, 2002, 04:03 PM: Message edited by: DarkAngel ]</small>

[Arkangel]

Ho, ho, ho......well, I have enjoyed myself today. Apart from getting looooads of shit presents, getting pissed ($drunk) and nearly killing myself cycling downhill from my father's to my mother's house in pitch darkness, I made some of this castable thermite, according to Mr Cool's 6/4 mix.

The dry powder worked a treat, and the little steel petri style dish I normally test small amounts of comp on is now a heap of slag. It was about 30 grams in a pile, and although it burnt hesitantly at times, it did so almost completely. I used an inch or two of sparkler to light it.

The remainder of the 300g mix I put in a small plastic pot, of the type that Skylighter use for supplying chems, and added water, mixing until it was a smooth paste. That set on my radiator within 20 minutes, and since it's narrower at the bottom, I was able to pop the solid mass out like an ice cube. It's now going to dry overnight and I'll try it in the morning.

If you get a few of these pots (and I will), you'd be able to cast loads of these very easily. Thinking back to Zaibatsu's idea of a thick walled cup, if you do were to push a cardboard tube into the mix (like a smartie tube), it would set in place and you'd have a nice void down the centre of your casting. It then just remains to drill out the hole for the sparkler igniter and you're done.

If you do cast a few of these, for storage, once they were completely dry, I'd be inclined to coat them in lacquer, or thick paint, to stop them from reabsorbing water in damp conditions.

I'll let you know how my 300g charge works tomorrow. If it is successful, there is loads of scrap iron at a place near here, so I'll try some more out on an engine block or two. :D

[nbk2000]

It can take a few days, or weeks, for the plaster to dry out naturally. That's why it's recommended to use an oven at low heat to do a through job of it. Otherwise, it's likely that the excess water will inhibit the burning.

The Black Books suggest using linseed oil to impregnate the charges exterior for water protection. Simply immerse the charge in it for a half hour.

[Arkangel]

Ok, then I'll do that, cheers. Oil is a good idea too, and a simpler method of application you couldn't wish for :)

Merry Christmas NBK!

(Bah! humbug! etc......)

[nbk2000]

Mr. Cool, is it just me or does the flame in the picture linked in your last post look rather huge for something so tiny?

Maybe, assuming it's not an optical illusion, the plastic (under extreme heating) is decomposing into gases that are acting as a fuel to increase the flames.

Common objects should always be included in pictures to provide a sense of scale. Something like a soda can or ruler would help determine the height of the flames. Though (just guesstimating) they look to be at least 4 feet high.

Any metal blobs on the target aren't likely to be unreacted aluminium. More likely is that it's aluminium oxide slag.

[xoo1246]

Impregnating with organic material will will draw energy decomposing this material, icreasing splatter due to gas generation etc. Sounds dangerous atleast if you want to use if for cutting applications.

[Mr Cool]

Yes, the flame was around 4 feet tall in that photo, maybe a bit more, although that was at its maximum. Most of the time it was more like 3.
It's not an optical illusion, they were real firery flames :D .
I think you're right, it's the vapourised/decomposed plastic burning, with the flame probably being stretched out by some strong convection currents.

Arkangel, did you do the test?

[Arkangel]

I did test my charge, and it did work, quite satisfyingly actually :D

I cast it, then stuck it on a hot radiator overnight. Next I drilled a 3/4" deep hole in it, and stuck it in the oven at 125 degrees for a couple of hours.

I had a 1.5" sparkler in the hole, but that failed to ignite it, so I had made up some new mix and put 30 grams of powder on the top, with another section of sparkler in that. Together, that lit ok, and burned the entire block with a VERY bright flame (turned night to day) and quite a bit of heat. Especially if you had plastic chips in it, I can well imagine you had a 4' high flame Mr Cool.

Next morning, I had a look at the test site, and found a lot of slag particles on top of the rock I burnt it on, and scattered around. I was doing other stuff, so didn't test what it was. I get the impression though, that it was not metallic, so I'll try a 7/3 mix, or more likely a 5/5 and see how we go.

Depending how well your additives go, Mr Cool, I'd be tempted to make future castings with a hollow in the top to have a powder or other primer.

[A-BOMB]

Well I just went out to home depot and bought a 5pound box and some al rod stock, and some MG firestarters at wallymart and made some Magnalium because I can grind it to a fine powder very easily, so I made some 20 gram blocks that I have drying under my furnance down in my basement right now should be dry in a hour or two.

[Jumala]

Interested in all I read before I tryed to ignite finest Al powder and some plaster. I heated it with a gas flame until it was red but nothing happens.
But this gives me an other idea.
I´ve often used Ammonium or sodiumpersulfate Na2S2O8 for making PCB in the past and it could be a much better oxidizer than a common sulfate. But it´s murphy´s law when I need some persufate it is all used up.
Perhaps someone has tested this before?
Na2S2O8 is cheap and available from most electronic suppliers.

[A-BOMB]

Well just tried in vain many times(like 11) to light that block but the best I could get was it lit for a few seconds at atime then it would go out :mad: how did you guy light your blocks off?

[nbk2000]

A couple of hours by the furnance is insufficient for drying. It has to be over 212*F for it to dry out properly. Otherwise there's going to be free water trapped inside of the plaster that's going to inhibit combustion.

I had that happen when I first tried making these. Drying overnight at 250*F did the trick just fine. :)

[A-BOMB]

It was not by the furnace it was under the burner assembly, but your probaly right so I'll try it again.

[arm]

Sorry to bring back a old thread but i found this to be be a very easily ignitable CaSO4 mix which still burns through steel (only tested powdered comp.).

Al : 25
CaSO4 : 25
KNO3 : 25
S : 25

Approx 4g melted a 40mm hole in the top of a baked bean tin and was ignited with plain old blackmatch. The mixture may be able to be 'tuned up' by adjusting the ratios.

[kingspaz]

sounds good. how fine were the powders?

[arm]

All powders were probably in the 300-400mesh region, although i suspect the aluminium may be a little on the coarse side.

[A-BOMB]

Well since its summer I just got out my blender and made about a cup of 20-300 mesh AL powder, Right now I have 4 20 gram blocks drying in my oven, I got to get out of here haveing the oven on right now is just makes it too hot. They should be dry in a couple of hours. These block are diffrent from the others in that they have strips of MG through them to help keep them lit. In one is 20-50 mesh AL, the next is like 75-150 mesh, then 200-300 and the last AL dust.

[Mr Cool]

Zn/S is good for lighting this stuff, thus no need for sparklers, which may be hard to get at some times of year. Also it means that many small pellets of incendiary could simultaneously be ignited and dispersed by a Zn/S charge (for an interesting visual effect, not an incendiary device) :).
A friend of mine has recently cut down a load of trees from his field, and it was my job to reduce them to ashes :D. 100g plaster incendiary charges surrounded by candles played a large part in doing this, and they performed very well.

[A-BOMB]

What ratios do you think would be good for the ZN/S? Also I just found out that you can use alcohol instead of water in some instances, I used 93% isonpronal alcohol in my new blocks some were really hard and burned great, others were crumbly and burn spazistic, burning for a second then sputtering and then burning again. The MG wires that I put in them helped with ignition and staying together while burning. I'll try a 50/50 mix of plaster and red iron oxide, and mallinum in a 40-30-30 mix.

[Arkangel]

Odd that this thread should surface again - I've just finished 12 1kg charges:D

They were cast and dried, then had a 1" dia hole cut 1" deep, in the top. There was a central hole !/2" deeper, into which I put a 2" length of sparkler - which had PIC/fuse taped to it. The main hole was then filled with some loose mixture - enhanced with 30% flake Al, and sealed with a hotglued plastic disc.

They can therefore be lit easily with a match or lighter, and are ideal ready to use incendiaries/flares.

Tried one last night, and since they were several times larger than the previous ones I've tested, I was curious to see what they'd do. It seems the body of the charge acts as a crucible, letting the whole thing gather a huge amount of heat. After it was all burnt, there was a huge heap of white hot soil and slag, which lasted for a good 5 minutes - SWEEEEET!!!!!!!!

(Finally got rid of all my fibreglass Al:D)

[A-BOMB]

Well its been awhile since this topic was up, and its also been awhile since I've posted in great amount. So here is goes I just made up someing new I think I was able to get into my lab acouple of days ago now that I got a new heater It was unbearbly cold without one even for being underground. I was just reading the forum on my laptop while waiting for my AL to finish in the blender. And I rememberd this topic so out came that chems, So I mixed up a batch of this stuff, Its a mix of jellied DBSP, Stronium nitrate flare comp, 20-300 mesh AL, and a large bit of ground up sparkler. In a ratio of about 50% DBSP, 25% SRN03 flare, 25% AL and about 25% sparkler I know these don't add up right but I was just mixing things to getter by volume, I was about a 1.25 cups of DBSP jelly, a bit more than .5 cups SRN03 flare, and abit more then .5 cups AL and about the same for the sparkler. And then extra bit of KN03 for some more kick. I added a bunch of acetone to get it to mix better then I took a odd ice cube tray that I had that make cube a little bigger that sugar cubes and I injected it into each slot and once they dried they burnt like crazy. And another plus is that they are stackable are pretty much unitform in size and burn rate. I'll get a video of some burning in later when its dark.

[Blackhawk]

Uhh, your ratio ends up to be 150% btw. How are you blending your Al powder, as per the other thread with a liquid and foil in a food processor?

[A-BOMB]

Ya, I was just mixing things together and takeing a little bit out drying it and seeing how it burned. And ya I was useing the AL+oil method from the other thread.

[dana_m_h]

CaSO4 is used in plaster it is an oxidizer (duh) in pyrotechnic devises / compositions couldnt you also use MgSO4 epsom salts (also an oxidizer duh) or is there problems with MgSO4 in pyrotechnic devises / compositions? just wondering

[cracker]

Here are some excellent Patented Thermite formulas using Magnesium Sulfate, Calcium Sulfate, & Barium Sulfate. look on the lower end of the page for the recipes. >http://www.patentstorm.us/patents/5062903-description.html

[Bacon46]

The flash composition that I use is 2:1, KClO3 / Al. Simple and effective.

The same ratio using KClO4 works just as well and is much safer. I use KClO3 because most of the flash I make I use to make exploding targets.

I use 8 – 10 micron atomized Al. The shape varies but it is mostly spherical.

I run the composition in a REMOTELY OPERATED rod mill for one hour. The grinding rods are ¾” aluminum tube filled with Bismuth. Lead would be fine. I happened to have 50 lbs of Bismuth lying around.

I am not recommending that anyone put flash composition in a rod or ball mill. I am just stating how I do it.

The first time I used the rod mill to mix flash I ran it for one hour. This produced the best flash I had ever seen. 2oz (56g) unconfined made a very loud, but low report, and a very bright flash. The same amount confined shakes the ground under your feet and turns a microwave oven into shrapnel. 3g loosely confined makes a very loud report. You don't even have to plug the ends of the tube.


While making my second or third batch I decided to run the rod mill for 12 hours. I don’t know why! The end result was garbage that would barley burn. I wound up adding charcoal and coarse Al and using it to ignite Thermite and KNO3/Sucrose rocket motors. Strange!

The link below is to a slide presentation of 20g of KClO3 / Al flash burning. There are ten images taken .07 seconds apart. Elapsed time from the first image to the last is seven tenths of a second.

http://img187.imageshack.us/slideshow/player.php?id=img187/7444/1173974437a84.smil

I have plenty of CaSO4 in the form of Plaster of Paris and Drywall Joint Compound and plenty of atomized Al. I will experiment with solid incendiary compositions this afternoon.

I should have paid closer attention to the date on this thread. Looks like I was beating a dead horse.:(

[Bacon46]

I have plenty of CaSO4 in the form of Plaster of Paris and Drywall Joint Compound and plenty of atomized Al. I will experiment with solid incendiary compositions this afternoon.

I am finally getting around to posting the results from the experiments I ran back in March. This composition shows promise.

USG “Easy Sand” Lightweight Setting Type Joint Compound. 41%

o Plaster of Paris (CaSO4) >60%

o Limestone <10%

o Or Dolomite (CaMg(CO3)2) 10%

o Expanded Perlite <10%

o Mica <10%
Atomized Al (8 – 10 micron) 27%

KNO3 - 30%

Fe2O3 - 2%

This composition was mixed with enough H2O to form slurry with the consistency of pancake batter, poured into a soup can and placed in the sun to dry.

In less than two hours the composition had hardened and shattered. There where fragments scattered in about a 6’ radius. Blew it right out of the can! The heat from the sun, the plaster drying and from the reaction between the KNO3 and Al must have caused air trapped in the mixture to expand and shatter the casting. The smell of ammonia was very strong and the pieces where too hot to be handled with bare hands.

Once the chunks cooled they ignited with a small amount of sparkler mix and a piece of visco fuse. It burned hot! The reaction left a hard slag that remained hot for a minute or so.

Anyone know what the glowing red product of this reaction might be? Once cooled it has similar properties to glass. Very hard and breaks or shatters leaving sharp edges.

See attached video.

<a href="http://img532.imageshack.us/my.php?image=drywallmudincendairywg6.flv"><img src="http://img532.imageshack.us/img532/7089/drywallmudincendairywg6.flv.th.jpg"/></a>

[Cobalt.45]

Buffer the comp with ~1% boric acid mixed into the water that you use to form the slurry.

This should help in stopping the evolution of H.

[Bert]

The large ammounts of carbonate will likely use up a 1% admixture of boric acid long before drying... Damned hard to keep a mix with that much carbonate mildly acidic, I would think. If you don't want ammonia, remove the nitrate. It's not needed except to lower ignition point.

[Bacon46]

If you don't want ammonia, remove the nitrate. It's not needed except to lower ignition point.

I could be wrong, but it seems to me that this composition needs some sort of oxidizer or it won’t burn at all.

Are you suggesting I replace the nitrate with different oxidizer like a chlorate or perchlorate or just remove the nitrate?:confused:

I know by checking Megalos OTC chemical survey that Boric Acid is available over the counter. Can anyone tell me how it is sold? Is it in the garden department as an insecticide, the pharmacy as an antiseptic, etc?

[Cindor]

Sulfates and oxides (among others) are oxidizers as well as chlorates, perchlorates and nitrates.

I've made bricks with Calcium Sulfate, Iron(III) Oxide and Al (I think it was 2/1/1) that work just perfect.

[knowledgehungry]

I use 60/40 ratio and light with a sparkler inserted into a hole in the composition. It never fails.

I used half a soda cans worth to start a campfire. Not one of the pieces of wood in the fire was under 2 inches diameter, I made a teepee with them, placed the device in the middle, lit the fuse and had an instant 6 foot tall fire(the flame not the wood) it continued to burn like that after the device was spent.

That's about all the pyrotechnics/explosives I do anymore :(.

[Cobalt.45]

Boric acid is roach poison. Sold at WalMart as Enoz brand "Roach Away".

99% boric acid. 1 pound costs ~$4.00.

Despite who says what, 1% boric acid is all that's needed.

Plaster is mostly CaSO4, the comp in question is CaSO4, Al, saltpeter and water.

Just use the 1% boric acid.

In case this wasn't clear:rolleyes:, it's 1% of the weight of the comp, not the water. Forget about any carbonates.

There's really no need for any nitrate.

[Bacon46]

Excellent, thanks for the input.

My goal with this composition or variations of this composition is three fold.

1. Castable solid rocket propellant that doesn’t require melting on an external heat source. For this I think I will need an additional oxidizer like a nitrate or chlorate to increase the burn rate. I will experiment with both and use the Boric acid with the nitrate comp.

2. Castable Illumination flare: I would like to be able to cast it in the shape of a projectile to be fired from a 12ga shotgun or a 72mm mortar I am working on. For this I may try a two layer projectile. A thin layer (5%) with additional oxidizer as an ignition source so that I can get it to ignite with the propellant charge and the remaining 95% without the additional oxidizer as the illumination grain.

3. Castable Incendiary for fouling gun barrels or other mechanical devises and/or starting structure fires. Here I will definitely stay away from chlorates and nitrates and stick to Al, metal oxides and the CaSO4. I would like the option of firing this as a projectile as well but here I think I will drill a core in the center of grain and using a sparkler composition as an ignition source.

Since I’m on the subject of metal oxides; I have an almost unlimited supply very finely powdered “Mill Scale”. According to the internet searches I have done, “mill-scale is a hard brittle coating of several distinct layers of iron oxides formed during the processing of steel. It is magnetic in nature (Fe3O4 predominantly) with iron content ranging between 66 to 88%”. What I have is contaminated with the oil that the steel manufactures use to protect the steel from further oxidation during shipping and storage but this can be easily removed.

My source for the mill scale is a blacksmith shop. When they twist steel bars the mill scale flakes off. It is easily ball milled to a very fine powder. I have collected 10 lbs of the stuff. But I haven’t tried to use it yet.

Does anyone have any experience using mill scale in a pyrotechnic composition?

[Cobalt.45]

As an aside, don't discount the use of an enhancement like red iron oxide, as Cindor mentioned. You might want to research other burn rate modifiers, too. There are many.

I think your stated goals are attainable, well, maybe all except #1. Overcoming the power to weight issues may be tough.

I think it was nbk (possibly others, too) that have mentioned drying the hell out of it, after casting.

Good luck.

[nbk2000]

A cast rocket propellant, using KNO3/Iron Oxide/Fiberglass resin,that's machinable and very durable, more so than plaster.

http://www.nakka-rocketry.net/rnx_int.html

Add some aluminum and you'd have a nice torch effect. :)

[Bacon46]

Thanks NBK

I have been to Richards site a number of times but was so focused on the KNO3/Sucrose fuels I never bothered to look into what else he may be working with. I happen to have some epoxy resin on hand. It contains TiO2 as white pigment maybe I won't need to add Fe2O3.

[Cobalt.45]

Titanium Dioxide may help, but there are several others that may offer more benefit. Your epoxy has TiO2 already, so what the heck, take it along for the ride.

This site: http://www.wichitabuggywhip.com/fireworks/rockets/whistletests.html has a real good run- down of "catalysts" (burn rate enhancers or modifiers would be more accurate), as they relate to Whistle Mix.

I'm not suggesting that the results will mirror what will happen when you use the same chemicals in your comp, but I believe there is useful info to be found there, just the same.

If nothing else, the sound bites and video clips are entertaining.

[Bacon46]

This is another composition along the same lines.

After reading a thread on silicone fuse I started experimenting with different silicone base pyrotechnic compositions. I think the following composition, or variations of it could be used in illumination flares or incendiary devices. It’s moldable, it burns very hot and very bright.

Incendiary / Flare Composition
 Al – (3 micron powder)___________________ 22%
 KClO3 ________________________________ 44%
 Platinum Cure Silicone Rubber Part “A” ______17%
 Platinum Cure Silicone Rubber Part “B” ______17%

Platinum Cure Silicone is a two part silicone, mixed using equal parts of “A” & “B” by weight or volume. The pot life is 20 minutes or less and it cures completely in 6 hours. It is available at Smooth-On.com.
 $158.00 for 16lb (7.25kg) - 8lb (3.625kg) of both parts.
 $26.00 for 2lb (0.9kg) – 1lb (453.59g) of both parts.

GE Silicone II can be used with similar results and is available at your local hardware store.

It’s basically two parts KClO3/Al flash to one part silicone. (By weight)

Mixing was as follows:
Combined Al and KClO3 and ball milled for 1 hour. I have read that ball milling KClO3 / AL flash is dangerous due to the risk of explosion. I have done it many times without incident. Maybe I have been lucky. If you are going to ball mill KClO3 / AL flash I suggest doing it in a location with minimal risk to life and/or property and to start and stop the mill from a remote location. It’s as simple as using a long extension cord.

In a separate container thoroughly mix silicone parts “A” and “B”.
Added the Al / KClO3 composition to the mixed silicone, stirred or knead thoroughly. I kneaded in ½ teaspoon (2.5ml) Acetone to thin it enough to work with.

I ended up with “very sticky goo” with a consistency similar to cookie dough. I shaped it into a 1-1/2” (38mm) ball, stuck in a piece of visco fuse and let it cure.

The end result is a gray rubber product with a durometer of between 30 and 40 Shore “A” (About as hard as a pencil eraser) that lights easily and burns very energetically.

I decided to try to make a grenade type device that would throw burning chunks of this stuff in all directions and leave nothing behind but ashes. Although it still needs a little tweaking, I was quite happy with the initial results. The link below is to a video of the first test. I think I will try scoring the next device so that it breaks up into smaller fragments.

<a href="http://img531.imageshack.us/my.php?image=incendiarygrenadepostviyh1.flv"><img src="http://img531.imageshack.us/img531/8128/incendiarygrenadepostviyh1.flv.th.jpg"/></a>

To make the device shown in the video you will need

 Either Two Part Platinum Cure Silicone or GE Silicone II

 Flash Powder

 A mold. In this case a 2 ½” (63.5mm) pyrotechnic shell. Any round object that will release the silicone once it has cured will work.

 Fiberglass Drywall Joint Tape. (Available at you local hardware store)

 Visco fuse

 Acetone (Optional)

Assembly Instructions using Two Part Platinum Cure Silicone

1. Using the directions above; mix enough composition to cover the mold with a layer approximately 1/8” (3mm) thick. In this case that was 6oz (170g).

2. Spread the mixed composition onto the two halves of the mold. It’s a good idea to wear rubber gloves when working with this comp, it’s nasty, sticky stuff.

3. Once the composition cures remove the rubber from the plastic shell or whatever you used for a mold. This leaves you with two hollow hemispheres made of 100% “Incendiary Rubber” that you will later assemble into a hollow sphere.

4. Mix another 6oz (170g) batch of composition.

5. Cut 3 lengths of fiberglass joint tape long enough to wrap around the assembled sphere.

6. Place 5g of KClO3 / Al flash into one of the cured hemispheres and place the other hemisphere on top.

7. Tightly holding the two halves together, apply a thin layer of composition on as much of the spheres surface as is possible.

8. Wrap one of the pieces of fiberglass joint tape cut earlier around the sphere at the seam. Place the other two pieces so that as much of the surface of the sphere as possible is covered by the tape.
9. Cover the sphere with the remaining composition.

10. Before the composition cured I spread a few grams of flash in a pie tin and rolled the sphere in the flash. This eliminated the tack and allowed me to form it into a neat, smooth ball.

11. Once cured repeat steps 4 through 5 and 7 through10

12. Once this coat cures poke a small hole in the sphere and insert a length of fuse.

13. Apply layer of straight silicone (No flash mixed in) over the entire surface and allow it to cure.

The following link is to a slide show showing various stages of the process. There would have been more pictures had I worn gloves. I couldn’t handle the camera once my hands were covered with goo.

http://img394.imageshack.us/slideshow/player.php?id=img394/4379/1183644502v94.smil

It’s a laborious process but the device will almost certainly start a fire if thrown into a building or car. It leaves little evidence behind, no container fragments etc. it’s completely waterproof and it’s much safer for the user than a Molotov Cocktail.

[nbk2000]

This reminded me of a patent I saw.

In a preferred embodiment steel was used as the material for the ball 11 and the incendiary material was made up of a cured mixture of 25% by weight room temperature vulcanizing silicone rubber, 25% magnesium powder of 320 mesh particle size, and 50% by weight Fe3O4.

A suitable silicone rubber RTV is commercially available under the designation of Dow Corning 3110 RTV encapsulant.

The magnesium powder is preferably ground rather than spherical thus providing greater surface area. Alternatively, other metals can be used for the ball 11 and other incendiary materials can be used to fill the hollows therein ...

You don't need to use chlorate (with the attendant hazards), as a thermite composition will work just as well or better.

Also, I noticed the interior of your device is smooth. This is bad for ignition.

If you had the rough surface on the interior part, where your burster is, than it'd much more likely to ignite every piece, rather than random chunks.

Or, you could make cut stars using this composition, and place them inside a shell made of the same stuff, along with some loose powder as an igniter/burster.

[Bacon46]

You don't need to use chlorate (with the attendant hazards), as a thermite composition will work just as well or better.

Or, you could make cut stars using this composition, and place them inside a shell made of the same stuff, along with some loose powder as an igniter/burster.

I like the metallic ball or cylindrical containers shown in the patent. Short pieces of ¼” or ½” steel pipe packed with an incendiary composition would fly much farther increasing the area affected by the device.

The cut star idea lends itself better to leaving nothing but ashes behind. This was part of the reason for making the container out of an incendiary composition. I am thinking that most of the ash / evidence that remained would be destroyed in the fire or in the process of extinguishing the fire. A fire investigator would find multiple points of ignition. It would be obvious that the fire was intentionally set but it would be difficult to find out what was used to set it. I will make another one using stars this weekend.

It may be a while before I post the results. I have to travel quite a ways to find a safe area to set these things off. Wild fire can be a real problem around here in the summer. I had to run around putting out small fires after I set off the one in the video. A couple of chunks traveled farther than expected. There is plenty of barren land close to town but it is all indian reservation. You think that's a coincidence?:D

I will have to experiment with the Thermite silicone compositions. I don’t have a good source for affordable magnesium powder and I’m not sure I can get Al / Fe3O4 Thermite to ignite with the burst charge. Maybe a piece of Mg ribbon in each star.

[Cobalt.45]

Hey Bacon

For the thermite-type incendiary "stars", you might try a hot prime using Si:

Si Hot Prime
40% KNO3
40 Silicon
20 Meal D
+5 Dextrin

Si Prime Ellern #166 MC pg. 359 PGII 29 AFN 29; PGII 29 AFN 158
54% Potassium nitrate
40 Silicon
6 Charcoal
+5 Dextrin

Or either of these, both pretty hot:

This from : PGII Bulletin 29, American Fireworks News 158, MC
54% Potassium nitrate
40 Mg
6 Charcoal
+5 Dextrin

This from : Bob Cardwell, Pyrotechnica V
57.2% Potassium nitrate
11.4 Mg
11.4Sulfur; 11.4Charcoal
5.7 Aluminum
2.9 Dextrin

This, along with a central burst charge surrounded with KP or BP coated rice hulls should get things going quite nicely. For a basic device, only the prime and a BP burst charge should be enough. A flash burst charge wouldn't be the best bet in this case, IMHO. Good luck.

You sure have a sweet area to blow shit up!

[nbk2000]

You could always coat the cut-stars with the silicone/flash mix you already made, which would surely ignite them.