ZoiDman, so is the gunk that forms on the coil related to flavoring? That is something else I wonder if anyone is trying to research.
I’m not sure if we can draw a box around flavoring and say that it is the sole cause of “gunk” build up on a atomizer coil.
There are 6 basic components of e-juice.
PG
VG
Nicotine
Flavoring
Sweetener
Artificial Coloring
What I have observed is that some juices case gunk buildup much faster than others. The ones I have noticed to be the worst are Colored, Sweet, Heavily Flavored juice. The ones that I see the least in are Uncolored, mildly sweetened, flavored juices.
I believe the gunk is either compounds that have higher boiling points than PG,VG or nicotine. Hence they are not vaporized. Or they are compounds that “caramelize” in the presents of heat. Or a combination of both.
So is it the flavoring? The sweetener? Or perhaps it is the artificial coloring? Very difficult to say.
The only thing I am sure of is that Artificial coloring should be phased out from All e-juices. It serves no purpose and it’s potential health risks while vaping are unknown.