Sciencemadness Discussion Board

KClO3 + candle wax: NO reaction ??

metalresearcher - 11-10-2013 at 12:55

As we all know, KClO3 is a strong oxidizer and should be handled with care when in combination with combustibles.
So I tried with candle wax. A small 'waxine' candle consisting of a thin aluminum container of 4cm diameter and 3cm high which was nearly empty. I put a few g of KClO3 into it and rubbed it gently into the wax. I lighted it with a lighter with no result.
Putting a bit of KClO3+sugar as helper in it let the latter mixture burn fast as expected but did not trigger the candle wax mixture. Only holding a Bunsen burner in its hottest position (air fully open) let it react: small lilac flames erupting.

Why does this react so poorly ?

WPK0129 - 11-10-2013 at 13:23

Well, this could be it: the candle burns as the wax flows into the wick, to supply the flame with fuel. The KNO3 isn't soluble in the wax, so it won't flow into the wick with the wax - rather, it'll be left behind with the unburned wax.

Jump to 4:40...
http://www.youtube.com/watch?v=46AdVDtSV6c

They melt the KNO3 here (300-some-odd degrees Celsius). That high heat needed to activate the reaction doesn't seem unusual.

Pyro - 11-10-2013 at 13:26

it's KClO3, not KNO3.
solubility shouldn't make a difference.
you will need more KClO3 than paraffin to get a good burn IIRC. but why would you want to do this anyway?

WPK0129 - 11-10-2013 at 13:34

Of course solubility should make a difference. How do you physically get the KClO3 into the flame to react if it's not soluble in the wax? You can't react something that's not there (i.e., in the wick).

[EDIT] Or maybe I just don't understand what you're trying to do...

[Edited on 11-10-2013 by WPK0129]

Pyro - 11-10-2013 at 14:08

I was under the impression that he put some KClO3 on one of those large candles.
Look at the reaction between KNO3/KClO3 and sugar. they are both solids, only when they are heated do they react, same with flashbangs (KClO4+Al) don't try to tell me that KClO4 is soluble in Al :P

the heat from the flame is plenty to ignite most KClO3/fuel mixes

WPK0129 - 11-10-2013 at 14:21

lol... fair enough.

I'm curious now. The internet says KClO3 is soluble in glycerol - if you made a lamp out of glycerol and a wick and lit it, then put it out, added KClO3, and lit it again - would you see a noticeable difference in the flame? Makes me wish I actually had either of those things so I could try it out.

Metacelsus - 11-10-2013 at 15:44

Mixing potassium chlorate and organic compounds and lighting them on fire is a bad idea, especially when confining the mixture in a metal container. It sounds like a good way to make an unintentional pipe bomb.

I hypothesize that the melting point of the wax was above the decomposition temperature of potassium chlorate, and that is why it didn't affect the flame. However, if most of the wax were to burn off, leaving the potassium chlorate exposed to the flame, then an explosion might ensue. If you do want it to change the flame, I suggest impregnating the wick with it, instead of putting it in the wax. You wouldn't need to use as much, so it would be safer.

[Edited on 11-10-2013 by Cheddite Cheese]

Antiswat - 12-10-2013 at 05:43

one should make a list of what KClO3 burns with, and measure the burn rate..
surprisingly it reacts with ascorbic acid very well when drymixed, very heat sensitive when wetmixed and then boiled off, very close to 100*C it ignites
what i found more interesting however was with citric acid
good potential in that mix when wetmixed

i would perhaps suggest its because of that the wax melts, and liquids reacts poor with solids, relative to solid - solid
gas - gas
or ofcourse liquid - liquid

LiClO4 reacts unexpectedly slow with magnesium, as the lithium perchlorate melts at the reaction temperature, and it basically turns into a slow thermite like reaction, or well fast.. tonnes of sparks

perhaps you want to adjust the ratios?
actually by what i know the 'active ingredient' is parrafine, you might want to try pure parrafine with KClO3, then just use so little that you can just exactly slightly soak it? vaseline is pretty well semi-liquid and it reacts quite well with KClO3

jock88 - 12-10-2013 at 16:03


KClO3 + wax has been used a a rocket fuel.

macckone - 13-10-2013 at 11:01

KClO3 and wax will only burn if intimately mixed. In pyrotechnic displays this would usually be mixed as solids and then slightly heated (water bath) to fuse the mixture. The addition of a powdered metal such as aluminum or magnesium is added to accelerate the reaction. Such mixtures can be explosive so be careful. Avoid contact with sulphur compounds. utahpryo.org has useful information.

jock88 - 14-10-2013 at 07:54


Actually it was a mixture of Charcoal + KClO3 + wax (as a binder) that was used as the rocket fuel AFAICR.

PHILOU Zrealone - 14-10-2013 at 11:50

In a not so far past, I used to play with NaCl/NaClO3 (40/60) (weed killer now banned by EU because some stupid guys reading sodium chloratum, thought it was sodium chloride and was intoxicated increasing statistics on chemical injuries due to house chems) and candle wax for years...
Note that NaClO3 is not KClO3. The later is harder to ignite because it is waterfree and has a higher mp this is proven by KClO3/C mixes what are harder to ignite than NaClO3/C

The tiny aluminium candle wax you speak about was used with its fuse...the wax was molten separately and the empty aluminium cup with its fuse was used, filled with one tea spoon of NaClO3/NaCl, then molten wax (caution not too hot or O2 bubbles comes out of the NaClO3 (you should be able to put rapidly your finger into the wax without burning yourself (so 50-60°C)), then again NaClO3...up to the upside of the cup.
After cooling the candle looks like a normal candle.
But when burning at first eveything is normal, after a few dozens of minutes the flame doesnt stick anymore to the fuse like a normal candle because some tiny O2 bubbles comes to the surface and little by little all the wax becomes a flame (about 10 cm high) in an aliminium cup....the wax volatilises slowly (a few extra dozens of minutes) and cristals of NaClO3/NaCl remains apparently unafected.
All of the sudden, the fuse that is completely carbonized with a wide red regio set the all now stoechiometric mix of overheated wax and NaClO3 into fire...with a fearce bright fire of 30 cm high, fusing the Aluminium cup, spaying NaCl dust in the air and a beautiful thick white fume smog. The first time I did it in a closed room...it was impossible to see through it and hard to see your own feet!

This is thus a dangerous incendiary device. This gave me the idea to develop cheap fumigens based on candle wax/ NaClO3 and suggar for immediate ignition by overheating... A coke can will make a hurge smoke cloud especially in cold winter day without wind...all the fumes fall onto the ground (cold air) after a small ascension.

In a forest by night the effect is wonderfull because the hurge bright flame spread the shadow of trees onto its own smog...what an atmosphere!

The recipient is invariably destroyed by the heat so beware of fire risk, if done in a house expect the firemen to come by!


[Edited on 14-10-2013 by PHILOU Zrealone]

jock88 - 15-10-2013 at 04:29

Quote: Originally posted by PHILOU Zrealone  


of fire risk, if done in a house expect the firemen to come by!


[Edited on 14-10-2013 by PHILOU Zrealone]


Expect the wife to give out too!


The whole thing sounds facinating.

Agricola - 8-11-2013 at 16:03

Lheure patented an explosive composed of potassium chlorate and paraffin wax. He claims "These explosives do not ignite in the air when touched say with a red-hot iron; in a fire they are consumed very quickly but without detonation.", thus agreeing with your observations, metalresearcher. The explosive is claimed to be as effective but safer than other chlorate explosives in use back then. See the attached files. The "A" file is French and the "B" is English.

Most old chlorate explosive compositions are dangerously sensitive to friction and other stimuli due to the mixing of chlorates with substances such as sulfur. Hats off to Lheure.

Attachment: chlorate_lheure1905a.pdf (69kB)
This file has been downloaded 291 times

Attachment: chlorate_lheure1905b.pdf (108kB)
This file has been downloaded 324 times


chemrox - 9-11-2013 at 09:27

Quote: Originally posted by WPK0129  
Well, this could be it: the candle burns as the wax flows into the wick, to supply the flame with fuel. The KNO3 isn't soluble in the wax, so it won't flow into the wick with the wax - rather, it'll be left behind with the unburned wax.

Jump to 4:40...
http://www.youtube.com/watch?v=46AdVDtSV6c

They melt the KNO3 here (300-some-odd degrees Celsius). That high heat needed to activate the reaction doesn't seem unusual.

Although he mention the wrong cmpd this is the explanation. You're only burning vaporized wax in a mixture of wax and chlorate. You'd have to thoroughly blend them and ignite them together to get the reaction.

Random - 13-11-2013 at 13:41

One could mix toilet paper with the wax to ignite the whole wax, thats usually how I start a larger wax fire.

PHILOU Zrealone - 13-11-2013 at 14:09

Quote: Originally posted by Random  
One could mix toilet paper with the wax to ignite the whole wax, thats usually how I start a larger wax fire.

Cotton wool with candle wax also works fine to make burning candle in cone shape. It starts as a normal candle and then after a while it is a whole fire pyramid :D

[Edited on 13-11-2013 by PHILOU Zrealone]