48 replies to this topic

[aapua]

Of course this mixture is stronger then BP... again, while I can see the logic, I can’t see why you will need K3[Fe(CN)6] in there. You can improve ignobility by adding small amount of charcoal or using a thin layer of BP premier. While Potassium ferricyanide is not particularly hazardous, it just adds an element that I’m not sure contribute much. Then again, I guess I will need to try it myself

What shell size do you use it on?

50mm and 75 mm silindrycal shells

[aapua]

OK, it's been silent here for a long time, but I'd like to come back to the topic "few interesting chemicals...". If you don't mind, of course.

UROTROPINE, or known as HEXAMINE as well. I really hoped to get more answers, or at least comments, because for me, could say, this chemical turned absolutely new page of making coloured flames.

I don't know why this chemical is not popular at all, I've seen only very few mixtures having it in. Somebody wrote in the topic of blue colour with KNO3 that he got beautiful blue with hexamine. 10 points!!! Sadly, the only time here somebody mentioned it.

Why it is so special (at least in my mind)? Let's divide flame and visual burning into 3 parts: the center of the flame, the top or edges and finally reflection of the flame from, let's say, walls. Make different mixtures. Keep the oxydizer constant and change fuel. Look at the flame very carefully. Sure you can see the difference between different chemicals. Of all possible chemicals I have tested, only urotropine gave all these 3 parts 10-point-quality.

One more interesting detail - you can get very good results even having no chlorine donor at all! Like this: 85 Sr(NO3)2 and 15 urotropine. This is very beautiful red. Replace urotropine with say dextrine, sulphur etc, and you'll see what I'm talking about. The same with Ba(NO3)2 and CuO. Pretty nice colours. But what if there is chlorine presented? Sure, it's better. What is good chemical for getting chlorine?

No doubt, NH4ClO4. I know, at least in UK and Australia you have real difficulties to get that chemical. Sad, sad. Anyway, I think it is the best one. But there are others.

Many, if not most mixtures seem to have PVC or parlon. PVC having 57% and parlon even more, 68% chlorine of its weight. There is even better - hexachlorethane C2Cl6. As high as 89,9% chlorine. But - you can't use every chemical containing chlorine. So, I would say, the last one gives almost nothing. As for PVC and parlon, effect is. But, take these 3 different parts of flame and then think carefully is that you expected for? This, earlier given very simple formulae. 85 Sr(NO3)2 and 15 urotropine. The flame, the edge and surroundings are red. Adding no matter how many or little of PVC turns the main flame to bright yellow. The edge will be a bit more red (dark red), but in my opinion, the whole result gets worse.

OK, you can't get NH4ClO4? No problem, cut off O4. What remains, is ammonia cloride, NH4Cl. In my experiments, it worked like AP - the colour of the flame gets more deep and dark. Here is the only problem - too many ammonia chloride in the mixture blocks the burning process. But, very simple one: Sr(NO3)2 83, urotropine 12 and ammonia chloride 5. Beautiful.

If you don't have nitrates, no problem. Works with carbonate as well.

Another interesting fact. Spectrometrically the best result of coloured flames would be with urotropine, magnesium dust and strontium chloride. Only this requires AP as a oxidizer. But, I tested KClO4 works pretty good as well.

So, if anybody likes something to add, even argue or what ever, be my guest. Especially I would like to know if anybody has already tried this chemical, or if he will try it, let me know, how it was???

Greetings, aapua

[Richard H]

Very interesting reading. I will certainly try some coloured flames with Sr(NO3)2. As for why hexamine is not often mentioned in formula's I am not sure. Perhaps cost? Lancaster seems to think so.

If folks do try these formula on an experimental scale, make sure it is in a well ventilated area.

[Creepin_pyro]

OK, you can't get NH4ClO4? No problem, cut off O4. What remains, is ammonia cloride, NH4Cl. In my experiments, it worked like AP - the colour of the flame gets more deep and dark. Here is the only problem - too many ammonia chloride in the mixture blocks the burning process. But, very simple one: Sr(NO3)2 83, urotropine 12 and ammonia chloride 5. Beautiful.

I've been looking for a worthwhile use for NH4CL for a while now. I'm going to have to find some Hexamine and give these a go . Thanks for the update - I had forgotten about this topic.

[Andrew]

I'm going to have to find some Hexamine and give these a go . 

Hexamine is available from high street shops. I wont say which, as it's a bit of a dodgy chemical to advertise it's open availability. It is probably somewhere on the forum already, but if isn't, and you do not know already, I'll PM you where to get it from.

[Pretty green flames]

It's no secret where to get hexamine from......

Go to a camping supply store, they sell it as camping stove tablets (or something similar)

[KingVinny]

Easiest way to get hexamine is by buying fuel tablets from somewhere, they are used for small camping stoves. You then need to crush them up and add the powder to some water as most of the tablets are covered in wax. Skim the impurities off, this is fairly easy as they float to the top then allow the water to evaporate and you are left with fairly pure hexamine.

[Andrew]

Easiest way to get hexamine is by buying fuel tablets from somewhere, they are used for small camping stoves.  You then need to crush them up and add the powder to some water as most of the tablets are covered in wax.  Skim the impurities off, this is fairly easy as they float to the top then allow the water to evaporate and you are left with fairly pure hexamine.

I'll have to try that one day. I was fairly sure that Hexamine was a waxy substance itself. From experience it is very difficult to powder.

[KingVinny]

The fuel tablets I got were covered in a lot of wax and had some wax mixed in. They crushed fairly easily and when the wax was removed and the water evaporated off, I was left with a lot of small crystals of hexamine. Smells kind of fishy not sure if it's supposed to.

[aapua]

Smells kind of fishy not sure if it's supposed to.

It's the smell it has to have. The thing is OK

[Pretty green flames]

Side note:

It should not smell of petrol (gasoline)

[adamw]

Yes it does smell fishy. The pyro factory I used to work at had a tub of it and it was quite nasty. Quite a few blue fomulas use it as a fuel, but it not mentioned in these formulas that it has a colour-enhancing property.

[aapua]

Quite a few blue fomulas use it as a fuel, but it not mentioned in these formulas that it has a colour-enhancing property.

As I wrote in my very first post, this chemical is commonly used in RUSSIAN mixtures. I could say, there is only few WITHOUT it actually. Once again, all I can say is: try, you won't regret...

[Richard H]

But, very simple one: Sr(NO3)2 83, urotropine 12 and ammonia chloride 5. Beautiful.

I decided to try this today. I prepared 10g of composition, weighing the components with a reasonably accurate (0.1g) set of pocket scales. I screened the chemicals together through a 60 mesh screen 3 times.

Got all excited as I placed the composition in a small pile on a test plate outside. Lit the length of blackmatch fuse and retired...Nothing The composition just would not ignite. I then took a blowtorch to it, still no luck. Maybe my strontium nitrate was too damp? Anyone?

I tried the strontium nitrate with magnesium 1:1 afterwards and it took fire immediately.

[Phoenix]

This comp looks a bit oxidiser heavy. Maybe that's the problem, and increasing the amount of fuel would help.