I think this is an important reason why we steep/age eliquids, because even if the different molecules of flavoring and glycerins may be well mixed, they won't be entirely homogenous until the flavoring is well distributed in the solution. I imagine it takes some time for a flavoring chemical to difuse into a solution of a different dilution than its own.
source video here: http://physicsbuzz.physicscentral.com/2013/11/dancing-droplets.html
So I'm barely ordering stuff to start dyi making. I happen to have a large quantity of premade juice from vapewild (max VG but very watery) that seems to have zero nic when it's supposed to be 6mg. I took a bottle I had just finished from vapejoose (100% vg, 6mg and very thick) that had residual left in it, added almost 30 ml of the vapewild juice, added 1.5 ml of 100mg 100% vg nicotine. I heated it up in the microwave for about 15 seconds then shook the life out of it. After a few minutes it was separated. Oily on the bottom, watery on top. I continued to shake it every few minutes and over a few days it still keeps separating. What am I doing wrong?
Edit: I'm going to make a separate post.
VG is very viscous so it needs a bit of heat. I don't think 15 seconds is enough. Let it get warm setting it on a space heater or in a crock pot instead. Once the glass is hot to the touch it should slosh around the bottle easily. If you have plastic bottles don't use a microwave or space heater. Try to keep the temperature at 150F for extended times. Another redditor said the microwave may have caused it but I don't know if that's the case. I've never micro'd ejuice myself. If getting it hotter doesn't work I would try adding drops of distilled water while the mixture is hot and shaken up, it may be that the 100%VG is resisting the diluted juice, and therefore may need some dilution of its own.