Tanks leak when they lose vacuum or the coil floods.
Tips to help maintain vacuum in your tank:
1) All o-rings in place and in good condition. Missing or faulty o-ring will allow air in/vacuum out.
2) Cracked glass
3) Chipped glass where the glass tube seals to the o-ring
4) Dirty mating surfaces, o-rings to metal or o-rings to glass
5) Over filling the tank. One of two things can happen here; 1) if you top the tank off all the way there is no room for the vacuum to form, leave a bit at the top and 2) depending on coil/chimney style you can flood the coil.
6) Juice is too thin. Either to high in PG content for the density of the wicking material or the tank/juice has been exposed to heat which thinned the juice out. Both of these result in the coil flooding and dumping juice through the air flow holes.
7) Letting the tank sit unused for extended periods of time, results in the coil saturating and flooding. Try turning the tank upside down to pull the juice away from the wicking material. Remember to let the wicking material rewet when you go back to vape it.
8) Close the airflow control/holes before opening the tank to fill it. Once you fill the tank but before opening the the airflow take a couple unpowered draws to help with the vacuum.
9) Coil should be finger tight, if you crank on it to hard you could deform the o-ring at the bottom of the coil.
10) Tanks needs to be assembled tightly to avoid leaks around the o-rings. As tight as you can get it with your hands.
11) Vaping at too low a temp, this will result in juice in the coil not being completely vaporized, which saturates/floods the coil.
12) Inhaling too hard with airflow closed down causing the coil to flood.
I'm sure I'm forgetting something but it's late. Hopefully others will chime in. I've included a couple videos. There are tons of "How to fix a leaking tank" videos on YouTube. I have not watched them all but feel safe in saying none of them will address the use of a tampon.
Good luck, only burnt hits suck more than a leaky tank.
