Have you ever wanted to color the flames of your candles? I've received several questions about how this might be achieved, including the following email:
I just posted this question to the forum but I am also interested in your take on it. I read the article about colored fire and decided to try to make a candle with a color flame!
First I tried dissolving the chems you suggested in the article (such as cupric chloride) into water until it was fully concentrated, and soaking some wicks overnight. After drying the wicks I found that on their own they do burn with a pretty flame (well, some of the chemicals), but once I tried adding wax to the mixture the natural color of the wax burning completely took away any desired effects.
Next I tried grinding up the chems into a fine powder and mixing as uniformly as possible with the wax. This was also unsuccessful and resulted in sporadic and weak color at best and often wouldn't even stay lit. Even when I could keep the particles from sinking to the bottom of the molten wax, they still do not burn correctly. I am convinced that in order to make a functioning candle with a color flame it is necessary to fully dissolve the salts and minerals listed in the article into the wax. Obviously the salts do not naturally dissolve and this got me thinking that maybe an emulsifier is necessary? Does that make sense? Thanks!
If making colored candle flames was easy, these candles would likely be available for sale. They are, but only when the candles burn liquid fuel. I would think you could make an alcohol lamp that burns a colored flame by attaching a wick to an alcohol lamp filled with fuel containing metal salts. The salts could be dissolved in a small amount of water, which would be mixable in alcohol. Some salts dissolve directly in alcohol. It's possible something similar could be achieved using fuel oil. I'm not sure a wax candle would ever work as well. Soaking the wick will produce a colored flame, much as if you burned paper or wood that has been soaked with metal salts, but the wick of a candle burns very slowly. Most of the flame results from the combustion of vaporized wax.
Has anyone tried making candles with colored flames? Do you have any suggestions for the reader who sent this e-mail or any tips about what will/won't work?
I too tried using paraffin wax but to no avail. I searched around and US patent 6921260 is probably the best description on the previous art and it's own design, careful reading of the patent reveals that it should be possible to make colored flame candles at home if you know what you're doing.
There is an old pdf article dated Dec 26, 1939 entitled Colored Flame Candle. In it William Fredericks used petroleum jelly as a fuel source with the mineral salt suspended in it. Although I haven't built the whole project, I did suspend copper chloride in petroleum jelly, and it burned very nicely. A nice blue flame. You have to play with the ratios. As I see it, there are two approaches. A. Drill an existing candle from the top, and fill the hole with warmed jelly, or B. Follow the instructions in the article by building a candle around an inner core of jelly. But I was asked a question which I need to answer: Is breathing the smoke of colored flame candles healthy? i.e. copper, strontium, potassium
Perhaps we can put our heads together on this project. I would like to get the colored flame candle project started. I saw that you have tried some things, but found they didn't work.
I would ask you not post this information yet. I would rather think this through with you and present the final project, rather than to publish the raw thinking of it. On the net I have found very chemically complicated candles (ethanolamine etc.)
I mixed copper I chloride with petroleum jelly, put a wick in it, and it burned very nicely blue. There was some moisture there, so it did stink a bit.
I read in one of the patent papers online that one of the problems is the amount of carbon particles in a candle flame. The suggestion was to use a palladium, vanadium or platinum chloride as a catalyst/accelerant (absorbing a small amount of this material on the wick) to increase the temperature. Not exactly cheap or readily available. But supposedly the orange flame is gone.
The other alternative is to burn smaller chain organic compounds, like citric acid or benzoic acid. I haven't tried these. Faerie flames advertises their candles are not paraffin, but crystals. Perhaps you have some ideas on other smaller molecules.
I find that alcohol flames color very nicely, but paraffin is just not very hot burning.
Yes, I am knowledgeable in chemistry with a B.Sc. in chemistry.
I am trying to make a color flame candle myself. I think the first step would be producing a candle that burns with a light blue/luminous flame, you need to get rid of the yellow. To do this you need a fuel that has a low carbon content. Things like paraffin and stearin burn yellow due to their high carbon content.
I don't think it's possible to make a good color flame candle with paraffin. A lot of patents seem to recommend Trimethyl Citrate. It's a waxy/crystalline solid that burns a light blue. But I can't find a place to get it, unless I want to buy it in industrial quantities!
Does anyone know where I can find trimethyl citrate? It's used as a food additive and cosmetic ingredient so I figure it isn't toxic.
I see a lot of soy candles on the market. I am wondering if perhaps this may work with soy or beeswax?
I have had a little success making a bluish candle flame by using copper desoldering braid.
It makes a surprisingly good candle wick. In order to get the color, however, I first heated it up to melt out the impregnated rosin. I then put it in saltwater, put another wire in saltwater (pretty much any metal except aluminum), made sure they didn't touch, and attached a 9 V battery to the wires-negative to the bare wire, positive to the copper braid. Within seconds, tiny bubbles will come off the - wire and blue-green stuff will form on the + braid. Leave it in for a while. Most of the green stuff will come off the braid into the water. The stuff is most likely copper chloride, formed from the chloride in the salt. After the braid is green (but before it falls apart), pull it out, trying not to knock off too much stuff. Dry it, preferably by hanging. Then try that as a wick.
I've only tried limited experiments, so your mileage may vary.
I'm working on Bryan's idea of using desoldering braid as a wick. I've had limited success so far. The theory is good it seems, but the main problem I've had is that the "wick" doesn't seem to be very good at drawing the molten wax up to the flame. The longest I've been able to keep one lit is about thirty seconds.
I'm thinking that either I did not allow the wick to remain in the saltwater solution long enough or perhaps I might benefit from a different variety of wax or possibly weaving the braid together with a more traditional wick.
take 1.5 cups of water and add 2 tbsp of salt (NaCl). dissolve 4 tbsp of borax. Then dissolve Add 1 tsp. of one of the following chemicals for colored flames: strontium chloride for a brilliant red flame, boric acid for a deep red flame, calcium for a red-orange flame, calcium chloride for a yellow-orange flame, table salt for a bright yellow flame, borax for a yellow-green flame, copper sulfate (blue vitriol/bluestone) for a green flame, calcium chloride for a blue flame, potassium sulfate or potassium nitrate (saltpeter) for a violet flame or Epsom salt for a white flame.
David Tran says:
Wouldn't the NaCl contaminate the flame with yellow and overpower the other colors?
Tim Billman says:
Check your colors. Boric acid burns green, calcium chloride burns orange/yellow, etc.
I can make solutions of boric acid (which can be bought at Ace Hardware-type stores 99% pure as a cockroach killer) and strontium chloride (an additive from pet stores for saltwater fish tanks) which burn nicely in a mixture of acetone and rubbing alcohol, but those solutions do not mix with melted candle wax (because it is non-polar.) The next thing I was going to try was finding an emulsifying agent that was safe to burn (i.e., probably not soap) to make a semisolid colloid with the compounds dissolved in the wax.
Any ideas on what my emulsifier could be? What can make oil and water mix besides soap?
For colored flames the element burn:
Lithium = Red
Potassium = Purple
Sulfur = Yellow
Copper/copper oxide = Blue/Green
I would just look at the elements and chemicals that they use in fireworks because those burn with different colors.