Sciencemadness Discussion Board

How to Make candles with colored flames?

lumpking69 - 6-7-2015 at 05:12

Howdy Folks!

As a hobby and to satisfy my curiosity I wanted to try to make candles with colored flames. My original idea was to use metallic salts but that was a bust. It didn't work for various reasons that should have been obvious to me.

But I was thinking about trying metallic soaps and I was wondering what you folks thought about that? If you think it might work, which chemicals exactly do you suggest I try?

I thank you all ahead of time!

kecskesajt - 6-7-2015 at 07:31

Maybe Boron trichloride reacter with paraffin.But the paraffin is quite unreactive.Or boron trioxide/borax finely powdered.But these sould NOT used indoors because of the fumes.

Mailinmypocket - 6-7-2015 at 08:05

You need to use wicks that have been treated with the coloring agent of your choice, found this:

http://www.ehow.com/how_7803467_make-colored-flame-candles.h...

blogfast25 - 6-7-2015 at 08:32

Quote: Originally posted by Mailinmypocket  
You need to use wicks that have been treated with the coloring agent of your choice, found this:

http://www.ehow.com/how_7803467_make-colored-flame-candles.h...


I have doubts re. how well this would work, certainly no photos are presented.

Candle wax flames are of relatively low temperature, not high enough for many elements to get excited, I think. Only one way to find out, of course...

DraconicAcid - 6-7-2015 at 08:37

I bought some candles that were supposed to have coloured flames once. The colours were very subtle.

blogfast25 - 6-7-2015 at 08:47

Quote: Originally posted by DraconicAcid  
I bought some candles that were supposed to have coloured flames once. The colours were very subtle.


With potassium it's so subtle you won't see it! (First hand experience, BTW)

Metacelsus - 6-7-2015 at 08:51

I've had limited success in making colored candles in the past. The wick needs to be impregnated with the coloring agent. I soaked mine in a saturated solution, then dried it. Only the stronger colors work well.

blogfast25 - 6-7-2015 at 08:55

Quote: Originally posted by Cheddite Cheese  
I've had limited success in making colored candles in the past. The wick needs to be impregnated with the coloring agent. I soaked mine in a saturated solution, then dried it. Only the stronger colors work well.


Did you try the magnesium one? Since as flame tests for Mg are hard to do even with max. heat Bunsens, I doubt a candle flame would work at all.

[Edited on 6-7-2015 by blogfast25]

UC235 - 6-7-2015 at 09:00

Hi. I posted to your thread on reddit a few days ago. I'm fairly sure that using regular paraffin wax will not work since the fuel inherently produces a bright yellow flame. You need trimethyl citrate or a similar compound. I have since found this info sheet confirming my earlier assertion:

http://cdn.teachersource.com/downloads/Colorflame_compositio...

The stearin, stearamide, and clove oil are almost certainly there to plasticize the trimethyl citrate, which is probably too crumbly by itself to make stable candles.

I am really unsure why they put potassium alum in the blue candle. I suspect it would work just as well without it added. Perhaps it provides opacity to the "wax"

[Edited on 6-7-2015 by UC235]

blogfast25 - 6-7-2015 at 09:52

Quote: Originally posted by UC235  

The stearin, stearamide, and clove oil are almost certainly there to plasticize the trimethyl citrate, which is probably too crumbly by itself to make stable candles.



Trimethyl citrate is described by Wiki as a "colorless, odorless liquid" (MP = - 55 C)

Stearin (glycerin tristearate) is a low melting solid.

[Edited on 6-7-2015 by blogfast25]

UC235 - 6-7-2015 at 10:13

Quote: Originally posted by blogfast25  


Trimethyl citrate is described by Wiki as a "colorless, odorless liquid" (MP = - 55 C)

Stearin (glycerin tristearate) is a low melting solid.

[Edited on 6-7-2015 by blogfast25]


There is not currently a wiki page for trimethyl citrate. You were probably reading the page for triethyl citrate.

Aldrich (http://www.sigmaaldrich.com/catalog/product/aldrich/27502) gives the melting point as 75-78C which is quite high for a candle wax, but probably necessary for very narrow-diameter birthday candles.

blogfast25 - 6-7-2015 at 12:08

Yep, my bad.

zed - 6-7-2015 at 13:47

Flame testing salts of elements themselves, produces only a transient color change in flames.

Your salts get "used up"

A bunsen burner produces a plenty hot enough flame. A candle not so much .

Blue you get for free......CO2 being formed. Yellow-Orange, from glowing carbon particles.

Green? Maybe you can get a little green? Fine copper wire in the wick?

Sodium works well, but sadly, it produces pretty much the same color as carbon particles.

phlogiston - 6-7-2015 at 15:49

I tried to make a red coloured candle by dissolving strontium soap and 1,4-dichlorobenzene (as a chlorine donor) in paraffin candle wax.
The soap was easily made from strontium nitrate and soft soap.
The 1,4-dichlorobenzene was from moth balls.

Although it was noticeably more red than the regular candles, it smelled terrible and produced massive amounts of soot. I would not call it a success.


boron and a lithium may be better choices for green/red respectively, as they do not require a chlorine donor.

[Edited on 7-7-2015 by phlogiston]

Metacelsus - 6-7-2015 at 16:36

Quote: Originally posted by blogfast25  
Quote: Originally posted by Cheddite Cheese  
I've had limited success in making colored candles in the past. The wick needs to be impregnated with the coloring agent. I soaked mine in a saturated solution, then dried it. Only the stronger colors work well.


Did you try the magnesium one? Since as flame tests for Mg are hard to do even with max. heat Bunsens, I doubt a candle flame would work at all.

[Edited on 6-7-2015 by blogfast25]


No, I did lithium, strontium, sodium, and barium. (Red and yellow worked best. The candle flame is yellow from incandescent carbon, so blue and green don't show up very well).

[Edited on 7-7-2015 by Cheddite Cheese]

CuReUS - 7-7-2015 at 04:05

I had a crazy idea a long time back.What would happen if peroxide was mixed with the wax and a candle was made from that ? while burning,the peroxide would decompose and release a lot of O2,which would give a blue flame due to complete combustion

Metacelsus - 7-7-2015 at 11:20

What kind of peroxide? Most organic ones still have a negative oxygen balance, and those that don't are quite unstable. It would need to dissolve in the wax, and more importantly, not explode when you lit the candle.

metalresearcher - 7-7-2015 at 11:40

Quote: Originally posted by blogfast25  

Did you try the magnesium one? Since as flame tests for Mg are hard to do even with max. heat Bunsens, I doubt a candle flame would work at all.


Mg does not have any flame color, unlike Na,K, Rb, Cs, Ca, Sr, Ba, I don't know why.

blogfast25 - 7-7-2015 at 14:14

Quote: Originally posted by metalresearcher  

Mg does not have any flame color, unlike Na,K, Rb, Cs, Ca, Sr, Ba, I don't know why.


Temperature: Mg requires higher T for emission to become significant.

Spectra of some elements, scroll down a bit for magnesium.

[Edited on 7-7-2015 by blogfast25]

CuReUS - 8-7-2015 at 01:20

Quote: Originally posted by Cheddite Cheese  
What kind of peroxide?

I had sodium perborate in mind.