Sorry this is (mostly) a repeat, but I wanted to post this here for newcomers, as it summarizes a lot of experiences.
I have been vaping all VG for about a year, since I realized PG was causing me some problems, sleepiness/low energy being the most annoying. Then I realized that I didn't need to put up with it, nor the taste that I never cared for. It was a revelation.
Anyway, no, there is no problem with nicotine stability in VG. I have several bottles of 100 mg/ml nicotine in VG that are over a year old, that were kept at room temp in the original bottles, and it's as good as new. No, there aren't some mysterious pockets unless the solution isn't well stirred in the first place, same as a PG solution.
I use all VG, except for the small quantities of PG that comes with flavoring, but it's not a matter of being religious about anything, I could live with 10 or maybe even 20% PG, before it gets very noticeable, but why should I?
DIY example: I start out with an empty 10 ml bottle, put it on the scale, zero it out, then add the nicotine in VG, which weighs about 1.2 g per ml, so for typical (for me) 10 mg/ml strength, I pour in 1.2 grams of 100mg/ml nicotine (1 ml). Then fill the bottle half way with VG (I usually use Humco that they sell at CVS etc), and add the flavoring recipe, 2% of this, 1% of that, the total doesn't ever exceed 20 drops, which works out to about 5-6%. People who use 25% flavoring aren't vaping VG/PG any longer, and I think they're very very brave. Then I add 5 drops (0.25 ml) of water, and 5 drops (0.20 ml) of PGA or 151 proof liquor. Then finish pouring in the VG to the 10 ml line. Shake under hot water tap, that gets the steeping going. Let it sit overnight in a warm spot, and by morning it's good to go. It wicks plenty well enough for me, you can always add a little more water if you want thinner juice, that doesn't hurt a thing either.
No, it's not an atty killer, I don't see an obvious difference from whenI vaped Dekang. There's no sugar or coloring in my DIY, if I want very sweet I add a drop or two of sucralose in PG. If I want more "dry", I use a drop or two of FA Bitter Wizard. I use small amounts of FA or PA flavoring. It tastes great, the vapor is great, the amounts of (possibly hazardous - we can't be sure) flavoring is at a minmum, no diacetyl, acetoin or acetylpropionyl. I feel great, no longer tired, no acid stomach, no dry mucous membranes. I'm very cautious about what I add to it, and I'm a very happy vaper, except that sometimes I can't find the door for all the vapor
Yes, Wizard, I've noticed that too, it takes a little more flavoring, but you know, this isn't a candy bar. I don't mean to sound sarcastic, but I'd rather live. And flavoring is the big unknown. My rule is "not more than 20 drops total" per 10 ml juice of typical strength flavorings in PG, like FlavourArt's (FA).
Burning juice is a nightmare with some atties, and it's hazardous. Some flavorings can break down to nasty stuff, PG is rather heat-stable, but VG starts to break down over 180 deg celcius. Normally an atty doesn't even get close to that temp, but if it's burning juice with loose glowing wires etc, you will know right away, the more VG in the juice, the easier to tell, because acrolein is formed, and you can detect truly minute amounts as a nasty burned grease taste before there's serious danger. There have been measurements taken, and no acrolein was ever detected under normal vaping conditions from VG. But I know it when I taste it, you will too, and you just have to avoid defective atomizers.
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