9 replies to this topic

[lew]

Good old 60/40 KNO3/sugar smoke comp has always been one of my favourite easy pyro projects.

The two main problems are-

1. The melting process makes me nervous. I am always afraid there will be accidental ignition of the comp.

2. It is very sticky an can be very hard to pour into moulds as it solidifys quickly.

I had an idea and thought I would ask other members if they have tried it before I test my thoery tommorow.

As golden syrup is basicaly 99% sugar, and already in a liquid (although quite viscous) form, I wondered if you could do a 60/40 ball milled KNO3/syrup mixture. In thoery it would still be pourable at room temp, and have no risk of accidental ignition, or causing second degree skin burns.

Is there a fatal flaw in my plan I am overlooking?

[BrightStar]

I think you are looking for something like the Rcandy composition here. This is a recrystalised potassium nitrate and sugar mix using a portion of liquid glucose (available in health food shops for cake making in the UK) or known as Corn syrup or Karo Syrup in the US. It makes the heating process much safer:

Recrystallised Caramel Rocket Fuel

Remember, you only need to melt the sugar, so why not mill your KNO3 as fine as possible, melt the sugar on its own and then mix the two quickly away from the heat. The molten sugar will still give you a nasty burn if spilt (I speak from painful experience), so wear good gloves.

If you have it, try stiring in 10% sulphur to the molten mix (also away from the heat - it ignites very easily) for even more smoke.

Edited by BrightStar, 08 August 2006 - 12:14 AM.

[fishy1]

I think ball milling golden syrup and kno3 won't work well, i'd guess your media will get caked up with it, and the mixture won't pour. Golden syrup is very viscous at best, and adding 60% kno3 will get you something like a dough. It also won't set.


Adding sulphur to kno3/sugar makes more smoke, but the smoke will make your eyes water, and won't be good to breathe.

[BrightStar]

I agree with fishy1 - the sulphur smoke is horrid to breathe, but sometimes you just need to clear the area ... I couldn't decide whether Lew was proposing ball milling the KNO3 then adding the syrup, or milling the two together resulting in a horribly messed up, gummed up mill (not advised).

You can make Rcandy with various sugars (even honey has been tried) but the results can be very hygroscopic and hence unreliable, as I suspect golden syrup would be. Just follow the Rcandy recipe and you will have a relatively safe, readily mouldable composition.

I'm sure others will agree that KNO3/Sugar is surprisingly energetic. As a beginner in the early days, I cast about 100g into a 1 inch id tube and lit it in the back garden. The resulting roaring jet of blue flame scared me silly. yes, this really is ROCKET FUEL... Be careful please!

Edited by BrightStar, 08 August 2006 - 07:23 PM.

[lew]

Thanks for your advice guys.

I wouldn't dream of putting syrup in my precious ball mill!

Still, after your advice, I tried it anyway, and the results are very interesting...

First of all, im using 'Lyles Golden Syrup' out of a plastic squeezy bottle.
I weighed out 8 grams in a plastic (disposable) cup, and added 12 grams of ball milled KNO3 (thus maintaining the basic 60)/40 mix)

Next, I mixd it with a plastic spoon. Supprisingly, it only took a minuite or so to become a smooth paste, and the KNO3 was mixed in very well. It did not become an uneven clumpy mix as expected, and instead, resembled a thick grey paste, around the same consistency as thick honey (not realy that much thicker than the syrup I started with)

Next, for an ignition test-

I spooned a blob around the size of 20 pence piece, and tried a normal (open flame) ignition with a cooks match on the end of a meter stick. Very hard to ignite, as soon as it started, it blew itself out.

Next, I tried running a peice of 1/16" visco through the blob - better, but still no full ignition.

So I tried a peice of thicker 1/8" for more heat - better still, but still fizzling out after the fuse has finished burning.

Finaly, I tried a few inches of good old PIC fuse with a knot tied in the piece protruding inside the blob of comp - This worked!

This comp burned very hot for around 15 seconds, glowing moltern red and giving off more smoke than a realy smokey thing, smoking a smokey pipe, whilst on fire!!

I reccomend this as a easy project to try and see for yourself, as most people will probably not believe me when I tell them that it works a LOT better than traditional melted 60/40 smoke comp, Producing a LOT more grey smoke, without the hassle and added danger of melting fuels and/or oxidiser mixtures, and this was without any added sulphur.

Yes it's hygroscopic, but so is traditional comp, but as its so easy to make, you can just knock some up when you need it.

It could be eaisily spooned into a cardboard mould at room tempreture.

Ignition may be a problem, but it can be easily overcome with either PIC or mabey a BP booster.

I would give this semi-liquid smoke comp my top rating -

TWO THUMBS UP!!!!

[Asteroid]

Of course, as with most things you get what you pay for - Golden syrup is very expensive and so is PIC. Perhaps a jet lighter would work better, witha trail of comp to keep the heat going for ignition. I certainly like the safety aspect though - no accidental ignition and difficult deliberate ignition

[pyromaniac303]

Maybe the extra smoke was actually steam caused by the liquid in the syrup being driven off when it heated up... i think maybe use a solid prime of normal 60/40 smoke mixture or just BP in the end of the tube, then pour the rest in and seal up at the other end.

A reason why it could have ignited the 3rd time round is because the heat from the previous 2 fuses dried it out enough to ignite with the PIC (assuming you used the same fuse hole)

[rocket]

That?s because the comp is hygroscopic, meaning it absorbs water from the air. Keep it in an airtight container and it should be fine, putting some salt or calcium chloride in the container wouldn?t hurt ether.

[cunning_plan]

i was about to give this a go... could you perhaps add a dehydrating agent to it or simply pad it out with something.... it would make it bulky but most probably a bit easier to lightand set

il try tommorow...