I’ve tried out a bunch of different bottom coil changeable (BCC) clearmizers and tanks recently and have noticed a trend towards too much wicking in many of them. The ProTank, Viva, EVOD and Davide have all suffered from it to one degree or another. The symptom is a burnt hit and a quick puff into the mouthpiece (think blowing bubbles in a soda through a straw) usually corrects the issue for the short term. Typically, I see a few bubbles rising from the wick area to the top of the tank.
What this routine tells me is that there is a little too much wick in the head for the 80PG/20VG e-liquid I was using. After carefully pulling out a few strands of wick, it gets better. Pulling out a few more strands usually makes it perfect and I then get great flavor no matter how often I hit it. When there is no leakage from the base and almost no gurgling, I know I have the wicks just about perfect. The trick is to be patient when removing strands to avoid removing too much.
Why should you have to do this with a brand new clearomizer or replacement head you ask? My assumption is that the manufacturers build these with a thick enough wick to work well with the thinnest of e-liquids like 100% PG. If they made the wicks too thin, leakage and juice in the mouth would occur with thin liquids. It is also much more difficult to add a few strands of wick than to remove a few.
The process of pulling a few out is simple and requires only a pair of tweezers (or dexterous long fingernails) to complete. By doing so, a BCC can be custom tailored to suit any thickness of juice you want to put in it. Sure it would be nice if one size fit all, but the variety of e-liquids on the market and the limitations of the wicking material make that a difficult proposition. It would be nice if manufacturers would include mention of wick adjustment in their instructions, however.