I've said this elsewhere, but clipping the wicks so they're flush with the outside of the wick holes really, really helps if you don't want to dial in the juice thinning, if you're having trouble raising the air tube (some of them seat loosely), and if you don't want to sand the bottom of the tube. I've been vaping Boba's and a few other pure VG juices with CE3's, and doing a side-by-side comparison with an unclipped CE3 (washed, dried, no primer) and a clipped one (same), you'll see a large bubble of air come out of the wick hole every few drags when it's clipped, and tiny little bubbles struggle to come out when it's not. Dry hits and burning galore on the unclipped, and nice, clean hits when clipped - so long as you give it a few seconds for the bubble to come out when it tries to. It's not a total vacuum in there - vape away some juice, the wicks pull more in, air flows in to replace the juice that left, and the level of vacuum stays right where it needs to be. The air bubble is formed right at the wick hole, and too much wick in the way means you can't get a bubble big enough and buoyant enough to overcome the viscosity of thick juice. Too much wick, smaller bubbles form and end up stuck in the wick, and then you've got too much vacuum in the juice reservoir - juice came out, but not enough air replaced it - and that extra vacuum holds the juice up. Clearing a tiny bit of wick away from the mouths of the holes helps. Less wick, bigger bubbles form in the bigger opening, there you go.
Now, raising the air tube does the same thing, and it works great when it works. But I've noticed that some of my air tubes seat tight, and some seat relatively loose. The looser ones can't be raised, because when you put the silicone gasket back on top of them the act of pushing the gasket down to seal pushes the air tube back down. In those cases, I've resorted to sanding the bottom of the air tube, but be warned: it's trial and error to get the right gap, and if you don't take it slow by sanding a tiny bit, testing, sanding some more, testing, etc etc - super tedious! - you'll likely ruin your first attempts by sanding too much away and there goes just enough vacuum to soak the top of your battery!
So that's why I've turned to clipping the wicks. Pop off the outer tube, "brush" the wicks as flat as you can with a flat jeweler's screwdriver so they're sticking out as far as they can naturally, and clip them flush with the outside of the wick hole with a nail clippers.
Just make sure you mark the CE3s you've modified for thick juice if you do this - you don't want to accidentally put a regular PG juice in there and have a mess on your hands.
So yeah, in my opinion, best solutions to try, in order:
- Thin your juice - kind of a pain to get right with a new juice, but once you know how thin it needs to be you can whip up a thinned batch.
- Raise the air tube if it doesn't seat too loosely
- Clip the wicks
- Sand the air tube
And this isn't even getting into the really thick VG - I've got some Red Oak Swiss Dark that I can't vape unless I thin it AND use it on a modified CE3.
