different color flames

[VL2018]

I am trying to reverse engineer the process by which candles with colorfully burning flames (green, red, etc) are BEST made. What I mean specifically by best is that, having tested a few available products, I noted that quite often the result is underwhelming, with the colorful part of the flame being only a portion of the flame (just half of the flame, or sometimes even just the tip).

I have been trying a few things, including breaking down these products and finding where they incorporate the colorant salts, and have found that the easiest thing that is done is just getting some salt to stick onto the wick, but the better result is achieved by somehow incorporating the colorant into both the wick and the wax itself. I have been moderately successful in getting the colorant onto/into the wick, but this leads to the underwhelming result that only a small part of the flame is the target color.

The issue with adding the colorant salt to the wax is essentially one of solubility. Even if the salt is painstakingly suspended within the wax by carefully adding and mixing it as it sets, it does not travel to the flame with the rest of the wax in the melt pool, it just settles at the bottom of the melt pool.

I was almost ready to think it was impossible until I found a product (specifically the tealights produced by Joelson inc - colorflame.com) that performed beautifully, and when I melted the wax, removed the wick, and let it set with a fresh zinc core wick, and burned both separately, I found that both burned with the target color, and noted that even though I melted the wax, no salt precipitated out of it, indicating that they had found a way to dissolve rather than just suspend the salt.

I assume this was done either by pre-treating the salt somehow, or using an additive that enhanced its solubility in the wax melt. Does anyone have any ideas on how I might reverse engineer the ingredients in the Joelson product, or just generally have any experience with solubilizing salts in candle wax?

[TallTayl]

I’m glad you brought this into another topic. I did answer and your welcome post. But it’s better in its own thread.

 

The salts that you’re working with how finely pulverizer are they? Can you see grains or is it a super fine powder?

[VL2018]

Thanks for the reply!

There are both fine and not so fine powders. The Copper Sulfate is more like kosher salt, while the Strontium Chloride is like beach sand. I did try passing the Copper Sulfate through a spice grinder, and I didn't get much improvement. In either case, the finest available powder (from the bottle or after some processing) still didn't seem to incorporate much into the wax, although maybe a bit better than with the large grain powder.

[Kerven]

Be careful when creating candles with colored flames. There is a patent (a few, actually) filed for that, along with patents covering the use of photochromatic and thermochromatic pigments.

 

One of the patents relating to colored flames does include copper compounds and strontium salts. I didn't read into it to find the technique but the abstract mentions impregnating the wick. I'd assume you dissolve whatever it is you're using, saturate a raw wick with it, allow the wick to dry, prime the wick with wax, then continue as usual.

If Joelson's colorants are in the wax and not the wick, then I'm going to guess they aren't using salts unless the salts are microns small. Maybe stearates.

Although, another patent mentions the use of metallic chlorides that are soluble in the fuel. Maybe test for solubility in a variety of waxes?

Another patent uses perchlorates but other things are used to tame their combustion; the perchlorates are still dissolved.

Yet another uses organic acid salts of alkali metals and wicks intwined with metallic wires in examples.

There are numerous approaches to this...

 

 

[VL2018]

Thanks for the response! Very helpful!

Yes I have read quite a few different patents, and I haven't had much success dissolving any of my colorants, even when I use the additives that are included in the patents. I wonder if there is an aspect of process that I am missing - perhaps it works best at very specific temperature or pressure?

Would you be able to link me to the patent for the chlorides that were soluble in the fuel?

[Kerven]

I think this was the one.

It's a little confusing because it briefly mentions soluble materials before going into detail on how to suspend the materials in the fuel. I think the metallic salts are dissolved into the fuel and an enhancer is suspended in the fuel. No idea what the "nitrogenous fuel" could be. Paraffin, maybe? The candles seem to be tealights with metal cups. It's an old patent.