smoke bomb trouble shooting

[reubenc]

i mixed 30/20 (10 gram mixture of 6g KNo3 with 4g Sugar) mixture of KNo3 with normal table sugar.
i wrapped it up in a piece of kitchen paper towel and set it on fire.however, the mixture did not burn or even smoke.
all that happened was , the sugar melted.


i then mixed another batch and this time i melted it on a pan. the sugar melted in no time, but the K/no3 seem to still be in small crystal form.
the sugar finally turned black in colour and i stopped the heating process.
i put this melted mixture on a piece of paper towel and burnt the paper towel.again, nothing happened to the compound.only the paper burned.

what am i doing wrong?
how come the sugar melts and becomes black, and yet the KNo3 still is in crystal form.

please help me out as i need smoke bombs soon and its hard to come across where i live

[mil&co]

It'd be better to melt the sugar first (Not untill its brown, but untill there is no steam coming off), and the add powdered PN. But be aware, try this in small batches first.

I think this threat would've been more in place in the water cooler or in an existing topic.

By the way: It's KNO₃

[Lewis]

I'm not sure how you could screw up the ol' KNO3 + Sugar recipe. Works for me even when I toss them together dry. Maybe you're using mislabelled chemicals?

If I remember correctly, the KNO3 dosen't really melt, but its particles stick to the mass of melted sugar making the mixture more intimate.

You can try a few things that'll make it burn faster. One is using icing sugar, or try adding match heads to the cooling mix if you melt them together. You can also use sulfur, magnesium, and other things to change the effects. Just keep experimenting and I'm sure you'll figgure it out.

[BlackFalcoN]

A n00b is in no position to be correcting other n00bs.

Leave that to the professionals, eh? ;)


.................................................. ...

[reubenc]

Right.....
I appreciate the input (and also the flamming).
I am still new here.Anyway, I apologize to the moderator. (BlackFalcoN is NOT a moderator. NBK)
Yes, I admit not reading the Rules section before posting.

[simply RED]

What is wrong?

Your KNO3 is not KNO3 at all? The mix of potassium nitrate and sugar should ignite extremely easy with a match and burn very fast!

[deadman]

What is the source of your potassium nitrate? As simply RED pointed out, that is the only reason it wouldn't work. Even with very poor KNO3 it should light fairly easily. A few suggestions are to use a fuse if you can because using the comp on burning paper is only going to expose it to a moderatley cool flame for a short period. If your supply of KNO3 is prilled, crush it with a spoon if you have to.

On a side note to anyone who knows. How do you write subscript numbers so I won't have a huge 3 when writing KNO3 or others. Thanks.

[Chopper]

KNO₃ may be entered by typing KNO<_sub_>3<_/sub_>

Just note that you need to remove the underscores. These were inserted to prevent the board software from formatting it.

Just read the page's source for any little tricks like this.

[Alexires]

Yeah, reubenc there is something wrong there.

I'd hazard a guess and say that it isn't KNO3 that your using. You aren't using salt (because your sugar is melting), your "KNO3" isn't damp (because you've tried it in melted sugar).

Are you sure it isn't NH4NO3? If it is, you won't be able to set it off with a match/saucepan.

Make sure to grind the sugar and "KNO3" to about the same consistancy to help ensure good mixing.

Also, be VERY careful when making KNO3 + sugar mix in a saucepan. If your making alot, and the mix on the bottom of the pan lights up, you going to wish it hadn't. At the absolute best, you've have a ruined saucepan/stovetop. At worst? Probably bits of mix all over the room (and yourself) burning hot enough to crack glass. And a pissload of smoke that is a bitch when you breath it in.

Have a bucket (metal) full of lots water nearby to drop the saucepan in if you have to do it inside.

[bcc1985s12]

Is it possible that you are actually using ammonium nitrate? It can melt, but not at low temperatures, and it won't light very well or produce smoke with sugar. Just a thought. Where did you buy the KNO₃?

[c.Tech]

I’ve melted NH₄NO₃ before on a hotplate where the element was built in to the device. if a hotplate can melt it then I think a flame would.

Ammonium nitrate melts at 170C would a stove be able to reach this temperature?

You could try melting it with a blowtorch on a piece of metal and see if that works.

BTW why isn’t ammonium nitrate meant to be mixed with aluminum?

[Czech Guy]

It may just be that the potassium nitrate that you are using is far too impure i heard that it must be at least 34% pure potassium nitrate to work at all

[deadman]

Czech Guy: I don't think anyone who has put 2 minutes of research into finding suitable KNO₃ would end up with that low percentile of potassium nitrate. I do wish he would tell his source though. If he just picked up some off the wall stump remover, then he could have to go find some Grant's, Green Light, or Spectracide brand stump remover.

c. Tech: Well most home stoves have atleast 10,000 btu's and I'm sure that is enought to reach 170 degrees centigrade. Do not get used to careless practices such as holding blowtorches at metal plates. I suggest getting some real lab equipment.

There isn't really anything wrong with mixing aluminum with ammonium nitrate. It is called ammonal for convenience. The only real problem is you need very fine mesh. Ammonal is difficult to detonate compared to anfo. I wont go on being in a pyrotechnic thread. Do a search.

[me234]

reubenc: You say you just lit the paper and let the flame burn towards the mix?
How long was the mix in contact with the flame?
Have you tried lighting a mtch and submerging the still burning match head into the mix. Try that a couple of times or try putting matchhead powder on top of the alledged saltpeter/sugar. If powdered matchheads fail to ignite KNOKNO₃/Sucrose. Then it probably isn't KNO₃

[bcc1985s12]

I don't think we can help you any more until you tell us the scource of your KNO3.
I know this is off topic, but AN can readily melt on most stovetops, it just takes a little while. If you were told not to mix AN with alluminum, it is because it sensitizes the AN, making it more dangerous to store in large quantities at the end of a shooting range.

[nbk2000]

I used to decompose AN in a flask suspended in a clay pot (air bath) on the stove burner (electric) to make Nitrous Oxide (laughing gas), so you can quite easily do so.

But explosive decomposition is possible at a temperature not much higher than it's melting point, so don't get too eager with the heat, eh?;)

[Anareon]

The KNO₃ shouldn't melt. When it melts it decomposes and gives off the oxygen.

KNSU smoke mix should be brown, and depending on the size of your KNO₃ granules you may be able to see small white dots suspended in it.

It may be hard to light because of the relatively low surface area. A lit paper flame will need to be in contact for around 3-5 seconds to light.

Failing this mould a stick-like fuse using the mixture and light this, it should catch much easier.

[chillardbee]

I just made a batch of KNO3/sucrose yesterday. I was following the directions from Richard Nakka's Experimental rocketry website http://www.nakka-rocketry.net/ . the important thing is to mill your KNO3 fine weather you have a ball mill or use your wife’s coffee grinder, regular granulated sugar works well enough as your going to be melting it anyway. I used a 50/50 by volume mix of KNO3/Sugar with 10% water added to get a more intimate mix as stated on Richard’s website. I put this mix in a stainless steal bowl which sets in a frying pan of oil and bring the temp up to 250 Fahrenheit. I doesn’t take long for the water to evaporate once it is hot and I kept track of the temp with a candy thermometer. On Richards website it says you can bring the temp up to 370 Fahrenheit. Be sure to keep stirring as its melting and try not to let it caramelize to much as it will effect the burn rate to an extent (that’s more for if your using this as a rocket propellant) but your end product should be light tan in color. After it was melted I poured it out on aluminum foil in strands and some of it I rolled in my hands before it got to stiff (it’s still very hot at this point so I rolled very quickly). I took some out to try and what a beautiful burn it has. Nice even burn with no residue, lots of smoke, such energetic gases come off this that little pieces will take flight. I think to make more smoke the addition of zinc oxide would work. By the way, dextrin has a lower melting point and is not as hygroscopic as sucrose, formulas for that is on Richards site as well.

[seifullaah73]

You all seem like professionals in this area how did you learn about all this

[Frunk]

You all seem like professionals in this area how did you learn about all this

Experiments, google, roguesci.org and TFSE.

Seriously guys, screwing up a KNO3/Sugar mix is damn near impossible if that's KNO3 and sugar you're using. A poor ratio would just make it burn not as nicely, but it'd still burn.

[Anareon]

Experiments, google, roguesci.org and TFSE.

Seriously guys, screwing up a KNO3/Sugar mix is damn near impossible if that's KNO3 and sugar you're using. A poor ratio would just make it burn not as nicely, but it'd still burn.

A basic knowledge of chemistry won't go amiss, but isnt nessecary, and originally a view to a quick profit provided the motivation to learn alot. Combined these fueled themselves more and generated experience, probably the most important factor.

[Frunk]

A basic knowledge of chemistry won't go amiss

Actually, for me it's quite the contrary. I got my chemistry basics off the internet. Roguesci is probably the only thing that allows me to have perfect grades in high school chemistry right now. For example, we've just started stoich. in school but I started that six months ago. I've also done just about every experiment we do in my backyard with ghetto-rigged apparatus. Seriously, there's nothing like the motivation of not dying when it comes to learning stuff. I'm definately taking chemisty at college :D

Back on topic:
Reubenc, we used to make KNO₃/Sugar smoke bombs for paintball when I was younger. If your mixture turns black you have overcooked. Cook it on low heat until it turns caramel brown then mold it and stick a fuse in it. There are some proper step-by-step instructions on the internet at MULTIPLE places, including just about every scenario paintball site and United Nuclear.

Maybe your nitrate's the problem, I'd advise you to check out Frogfot's site (http://www.frogfot.com/synthesis/saltpetre.html). You can probably skip the sulfate precipitation steps, but a good recrystalization will give poor Potassium Nitrate a good boost.

[Mechanical_Man]

The same exact thing happened to me my first time. I figured out that I was doing several things wrong. First of all I was using the wrong kind of stump remover, the right kind is 'Grant's Stump Remover' it's like 98% KNO3. And Both ingrediants have to be as finely powdered as possible especially the KNO3. And when melting them togather do not make batch with a higher mass than 20g because it will spontaneously ignite. Melt and stir until it take the color of peanut butter, you'll be suprised at how much it actually looks like peanut butter. Well have fun, and burn on.

[Dr. Hextromeister]

I seriously doubt what you are using is KNO₃. If you are using a stump remover it could actually be ammonium sulfamate based instead.


As previously said, you can't really go wrong with KNO₃ and sugar...

[seaWasp]

reubenc,

Just speculation here, but the problem might be that you're using a paper towel to ignite the mixture. The paper towel might burn so quickly that there isn't enough heat buildup to ignite the KNO₃/sucrose mixture. Try lighting a match, and while the matchhead is still burning, hold it to the smoke mixture. I've noticed that smoke mixtures don't ignite instantly, and they do require some heat buildup.

Also make sure that both the KNO₃ and sugar are finely powdered. This may seem trivial, but it really helps. Invest in a ceramic mortar and pestle set. Or you can use a ghetto ball mill, like I do: buy a cheap stone polishing set, and fill the rock tumbler with marbles. Fill the rock tumbler with whatever you want to pulverize, and leave it on overnight. This works surprisingly well.

Regards,
seaWasp

[FUTI]

If you are using a stump remover it could actually be ammonium sulfamate based instead.

If Dr.Hextromeister is right about this....that compound can be usefull somewhere else...search the forum and if it your kind of play....play it if you like, and report result naturally, I don't have access to such stuff here.

[FebiFurx]

When I tried the mixture with Potassium Nitrate and Sugar took only few seconds to ignite and it was not so well powdered (I used a normal dish to powder the pellets of potassiun nitrate), after three seconds with the flame of the match in contact with the mixture the burning started. I think it's a problem of the nitrate, try to ask for some saltpeter to a butcher or ask specifically potassium nitrate in a gardening store (here in italy they did not say anything when I asked it) Better to me be sure about the component even if you risk they believe you a terrorist...

[Bacon46]

If you are going to continue to use stump remover as a source of KNO3 I would suggest cleaning it up via re-crystallization.

This method worked well for me:

Bring 450ml of water to a boil

Remove from heat and add 1lb of Grants Stump Remover. Stir until all the stump remover has dissolved.

Place a disposable aluminum foil baking pan, approximately 10” x 14” x 2” deep, outside where it will receive the most direct sunlight. It should be on a flat, level surface. You can buy the pans at the grocery store.

Pour the stump remover solution into the pan.

As the water evaporates you will notice that on the sides of the aluminum pan there are very tiny white crystals forming. They resemble white mold. I assume this is the binder used in the stump remover.

At the bottom of the pan you will see large clear crystals forming. This is the KNO3.

At the end of the process you end up with most of the binder stuck to the sides of the pan. The "binder" crystals will actually migrate to the outer surfaces of the pan and onto whatever surface the pan is sitting on.

The KNO3 stays in the bottom of the pan in the form of large clear crystals.

After all of the water has evaporated carefully remove the "binder" crystals and discard.
Take the remaining KNO3 crystals and grind into a fine powder.

You may have to vary the evaporation process, based on where you live.

I live in the desert where the daytime temperature in the winter is rarely below 70 degrees Fahrenheit and for most of the summer it is well above 100 in the shade, and 30% humidity is considered high. Here, in the summer, the process takes less than one day.

I have never done it, but I suppose it could be done in an oven at 175 degrees Fahrenheit. You would have to place the foil pan onto something that would catch the "binder" crystals that formed outside the pan or you would have a mess.

I have found that the aluminum foil pans are the only ones that work for this process. When attempting to use glass or plastic pans more of the "binder" crystals tend to stay on top of KNO3 crystals making them harder to separate.

It is an interesting process and I have no idea why it works the way it does. But at $5.00 per pound for stump remover an easier and much cheaper solution would be to purchase clean KNO3 from any one of the many sources on the internet for less than $2.00 per pound.

[nbk2000]

I've never heard of a binder being used in stump remover. :confused:

My jar of Green Light is a free-flowing fine white powder.

[Bacon46]

The Grants stump remover that I used was prilled and very hard to crush.

I did manage to crush the contents of the first bottle I purchased. I used the powder to make KNO3/Sucrose rocket propellant. When burned, the propellant left a waxy slag behind. This slag occasionally clogged the nozzle of the rocket motor. I assumed this was due to a binder used to form the “rock hard” prills.

The re-crystallization method I described earlier solved this problem.

[Frunk]

Stump remover sucks.
I can't stress this enough: find your local hippy hydroponics shop. They have funky fertilizers, syringes, beakers, thermometers, pH meters, etc.

They have no problems with selling you potassium (maybe even Ammonium) nitrate AND they won't ask questions, since they're probably already stoned out of their mind. I've just bought a 25 kg bag for 50$ CAN. 2$ Canadian a Kilogram, which is around 2 pounds. This is the exact product I bought. (http://www.scottsprohort.com/_documents/WSF/PetersProfessional/H4038.pdf) It's basically a lifetime supply for a backyard chemist, except if your really want to make a massive 70 pound instant smog bomb. It's the same price for AN BTW, I just don't have the motivation to do some 50 pound ANFO blasts.

It has some water soluble metal salts in very small percentages, so that's nothing a good recryst + coffee filter can't cure. Heck, you could even count the 0,2% Mg as a bonus :D

[Dr. Hextromeister]

If Dr.Hextromeister is right about this....that compound can be usefull somewhere else...search the forum and if it your kind of play....play it if you like, and report result naturally, I don't have access to such stuff here.


Wait, you're saying I can do something fun with this KG or so of AS? :)



Please, the search button reveals nothing to me.....

[cbi96]

hey, I have been making KN03 smoke bombs for a while, but my friend has requested that I make a "brick" for him. I find that when I make smoke bombs in large amounts, they are very sticky. I am using tree stump killer, which is available to me, and am using a 3 to 2 ratio, tree stump killer to sugar. An ideas on how to dry out the mixutre? A starch perhaps?

[Bacon46]

Either there is crap in your stump remover or it just so happens that the humidity has been higher when you are making larger batches. KNO3 / Sucrose is hydroscopic and becomes a sticky, gooey mess when it’s humid.

[Double-Oh-Zero]

I roll my mix into balls when half cool, then let them cool completely before wrapping in aluminium foil. It keeps forever.

However, I do find that lighting it has always been a bit of a downer, as the mix does not ignite till a small section of it is black, but then it burns itself out after about 2 sec. I'm trying to combat this, but have had no luck so far. (Fuse is unfortunately out of the question)

This only happens when the flame is applied for a long time (about 45sec, just enough to light it), and it seems that it needs a quick application of energy to ignite successfully. (Like a fuse). Anyway.

(BTW if anyone has a source for visco here in South Africa, let me know please. Importing is out though.)