Finally, I went to experiment with watermiscible(!!!) smoke-fluid as an ingredient when replacing the "water" of a lavalamp.
I assume you all know that, as given in the Crestworth Patents, glycol is (or has at one time been) an ingredient of the original mixture!
The colorless(!!!) liquid used in smoke-machines (!Note that there also is "oil-based" fluids, but I use a water-based here!) contains a non-toxic type of glycol which, afaik, can be either "propylene glycol" (PPG) or "polyethylene glycol" (PEG).
Unfortunately, over here (Germany) there's no regulation binding manufacturers to list the ingredients of such products, much less to indicate the mixing ratio. )-:
Yet, the price for one canister (5 litres = over 1 gallon) ranges between 10 and 25 Euros. In comparison: 250 ml (0.25 litres) of pure glycerin also cost 10 Euros in a pharmacy.
And my very first - bold and thus failed - experiment showed that 0.30 litres of smoke-fluid already are an overdose (once hot enough, all the wax shot up to the top and wouldn't sink again. >.< )
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I used a Mathmos Astro that previously had the liquid replaced with the common water/epsom salt/soap mix. I disposed the liquid, rinsed the bottle carefully and refilled it with tap-water.
! NOTE: As it can cause annoying complications, a bottle freshly filled from the tap should rest for at least one day, so that the air "dissolved" in the water can settle. !
I placed the bottle on the lamp-base, let it heat up for the prerequisite time and then started to add the smoke-fluid as I would do with a salt-solution (i.e. add a little, wait a little, repeat). It took about 120 millilitres to get the wax to rise.
! NOTE: The required amount may differ. Smoke-fluids contain different concentrations of glycol depending on the thickness of smoke they produce. The "heavier" the smoke, the higher the concentration. !
Now that I had the one large globe rising and falling, I added a few drops of a soap-solution I prepared earlier (1 drop of clear dishwashing liquid in a few millilitres of water). I'm still not happy with that, simply because the dishwash contains more than one substance including useless ingredients such as perfume or citric acid. I doubt that they're any good for lava lamp chemistry.
Anyways, with the water/smoke-fluid-mixture the wax proved to be much more "willing" to behave as desired and soon formed nice blobs. Once that was obtained and appeared to be stable I screwed on the lid and switched the lamp off.
SUMMARY (Remember this experiment was done with a Mathmos - The Original!)
The water-based, watermiscible and colorless smoke-fluid is a cheap and reliable source for a non-toxic type of glycol.
USE: It lowers the specific gravity of the water, allowing the wax to rise. It also appears to aid in the interaction of wax and detergent, which results in a much clearer mixture than what can be obtained using salt-solutions.
Now all that's left to find is the perfect(!) substance to replace the common dishwash.