8 replies to this topic

[Blackheart45]

Hello again, just a quick question for everyone: Can potassium chlorate and lactose be used to make white smoke candles in and of themselves? Every single smoke composition utilizing them (that I've come across at least) includes the use of a dye.

But as with the old nitrate/sugar mixture, can they simply be mixed together for anything approaching impressive results? If so, could someone enlighten me to the best ratios to use?

Thanks everyone!

[YT2095]

for Pure white smoke Titanium Dioxide should work quite well I believe.
it`s pretty Inert also and shouldn`t present any problems with side reactions, and it`s easily available in Pottery supply shops.

[Arthur Brown]

Smoke is a fine aerial dispersion of a solid, from BP it's all the potassium reaction salts.

In smoke B_mbs as on Youtube then they tend to say they use sucrose (sugar) or glucose (another sugar) with potassium nitrate, cautiously fused together. So again the smoke will be largely potassium salts in aerosol form.

Coloured smokes -think rescue smoke flares and parachute displays- are a cool burning organic fuel-oxidiser system and a large amount of dye. The dye is chosen to sublime before it decomposes.

Military high concealment smokes tend to have a high zinc content in the smoke and may well come from a compound which burns to aerosol zinc chloride - this smoke is very opaque to IR surveilance too.

Tioxide is available from artist's suppliers, and industrial paint suppliers BUT it is a solid and would need to be finely powdered then projected into the atmosphere. Titanium burns to quickly as turnings or dust. So yes it is an easy to obtain powder but it is not easy to use for smokes.

The mix you suggest is too close to the old chlorate and sugar pipe b**b - only used for bad purposes. It may be possible to modify it or only use it in smoke generating conditions, but I wouldnt like to try it. Chlorates have some bad reactions. There are some chemical incompatibilities which could cause really bad problems.

Keep looking on lots of sources inc ebay for the 1940s US military texts on smokes etc. Also keep researching current texts, there are lots of smoke compounds published. With smokes though the method of manufacture is as important as the formula. Practically every text on making fireworks has a chapter on smoke compounds, as they are often safer than hot fire or bang compounds. -Do NOT however assume that smokes are safe! In pyro safety is relative!

[BrightStar]

I have some notes from an old PGI presentation on military smokes that suggests the following:

Universal Smoke Fuel Mix
*********************
Sucrose: 28
Potassium Chlorate: 40
Magnesium Carbonate: 32

Granulate using thin NC laquer.

This fuel is used as a base for testing smoke additives (wax, terephthalic acid, colour dyes etc.) but will produce plenty of smoke on its own. Reducing the MgCO3 down to 5 parts results in a 'fast' version and you could try omitting it entirely.

There is apparently sometimes an issue with formation of hazardous magnesium chlorate when MgCO3 is used to neutralise chlorates in compositions so be careful.

Edited by BrightStar, 21 February 2008 - 01:42 PM.

[pyrotrev]

The best white smoke I ever made was by granulating a stoichiometric mixture of KNO3/sucrose, then using this to vapourise paraffin (candle) wax. With a suitable wind a 1Kg generator using this mix made between 1/2 and 3/4 mile of smoke

[Arthur Brown]

From COPAE by Tenney L Davis, A book you should have!

"White smoke is produced by burning a mixture of potassium
chlorate 3 parts, lactose 1, and finely powdered ammonium chloride
1. The smoke, which consists of finely divided ammonium
chloride, is not poisonous, and has found some use in connection
with the study of problems in ventilation.
For use in trench warfare, for the purpose of obscuring the
situation from the sight of the enemy, a very satisfactory dense
white or gray smoke is procured by burning a mixture of zinc
dust and hexachloroethane. The mixture requires a strong starting
fire. The smoke consists largely of finely divided zinc chloride"

[BrightStar]

"White smoke is produced by burning a mixture of potassium
chlorate 3 parts, lactose 1, and finely powdered ammonium chloride

I know this is a traditional formula, but YIKES ammonium and chlorate in the same composition Ammonium Chlorate is very, very scary indeed.

YT2095, any chance you could explain the chemistry of how we might end up with, or indeed avoid magnesium chlorate or ammonium chlorate forming in these or similar mixes?

Edited by BrightStar, 21 February 2008 - 07:06 PM.

[Blackheart45]

Wow, I didn't expect so many replies so quickly

At any rate, I have experimented with the Kno3+sugar and paraffin before, but didn't have any good results....perhaps too much wax to oxidizer? I would be interested in the potassium chlorate+ammonium chloride+lactose though. If, and only if, I could avoid ammonium chlorate formation.

Essentially I'm looking for a good quality non-toxic smoke that emits very little flame (or at least a cool burning flame)

[pyrotrev]

I know this is a traditional formula, but YIKES ammonium and chlorate in the same composition Ammonium Chlorate is very, very scary indeed.

YT2095, any chance you could explain the chemistry of how we might end up with, or indeed avoid magnesium chlorate or ammonium chlorate forming in these or similar mixes?

It's safe because KClO3 has the lowest solubility of any of the compounds that could be formed from the possible reactions. There's a law called the "law of minimum solubility" which says a chemical reaction will always go in the direction that precipitates out the least soluble compound. So if you mix KClO3 with ammonium perc. you have a big problem because KClO4 is a lot less soluble than KClO3, AP, and ammonium chlorate . But in the KClO3/NH4Cl mix, the KClO3 is the least soluble species, so the reaction doesn't happen.
The KNO3/sugar/wax thing needs (like a lot of smoke mixes) a certain amount of mechanical structure to make it work, you have to make sure that the smoke isn't ignited. In commercial smoke generators this is done by enclosing the mix with a smallish exit hole, having a metal gauze on top of the composition, and sometimes some gravel etc. on top of that to absorb heat. The ratio of heating mix to smoke compound will also need to be varied according to size, since larger generators will run hotter inside.

Edited by pyrotrev, 21 February 2008 - 11:38 PM.