I'm a tootle that has never used any of the equipment that I am now buying.
In my stockpiling efforts, I've acquired some authentic Aspire Triton V1s and V2s, and Lemo 2 RTAs. I have not used them yet, but I have disassembled them, and they are remarkably well made IMO. The threads are machined precisely, and there are gaskets in places where I wouldn't even think that they would be needed, yet no matter how well made the tank, there are always complaints about leaking in the reviews. Why? The most given advice is to keep them upright.
I'm planning on some authentic Griffin and Wotofo Serpent RTAs in the future as a hedge, comments on these are also welcome.
These are the things that I have learned cause leaking
1) Dealing with liquids in anything, this just doesn't include vaping, the most minute space liquid will find it and get out, this could caps on bottles, the list is long, most don't take this into account, the basic physics.
2) The wicking is not adequate to make a seal or proper blockade
3) Condensation in the chimney, this collects then drains down into the air chamber, so proper upkeep is essential here, but also continue drawing after the first button is let off of, this thoroughly cools off the coil and clears any lingering vapor to reduce it collecting on the walls and chimney
4) Coil is dirty, over time carbon and such build on the wire of the coil and crystalized sweeteners/impurities collect in the wicking, juice hits the wicking blockade and only the outer wire can vaporize liquid but not fast enough so excess flood falls into the air inlet, with the wire the carbon insulates the wire to wicking contact and excess flowing liquid drips into the inlet. Darker and sweeter liquids compound this, tobaccos, very sweet fruits and candy flavors, bakery, savory, desert, creamy, coffees, and yogurts are notorious coil gunkers so increase ruining coils and wicking quicker than clearer liquids, also very high VG liquids, VG is sweet so you get a double whammy with these.
5) Dud coil heads, not enough wicking sometimes, see #2 above
6) Torn Gaskets and seals, or worn out mashed, squished old gaskets and seals, #1
7) Bottom coils are notorious for this, they work off the physics of vacuum, liquid to air elasticity, and reverse pressure (vacuum cleaner as example works on reverse pressure, rapidly flowing air going up, if a hole in the chamber it will pull through that hole, tanks with bottom coils this reverse pressure helps pull liquid out of the tank into the wicking to wick properly). These tanks are also affected by external ambient air pressure (barometer level, rising up or going down in altitude) builds pressure to push liquid out the easiest avenue, or lowers balanced pressure in the air inlet/chamber/chimney to pull liquid in to equalize pressure. Temperature, going from a cold environment to a hot one, summer time leaving the house out into 100F summer noon time outside, this builds pressure in the tank as the liquid heats, basic physics, it will thin in viscosity (become thinner) and the liquid and air in the tank expand, the extra pressure and thinner viscocity can cause a flood gate being opened up.
8) Machining, a lot of tanks are machined well, but they are mass produced, you never know if a deep gouge or even a threading machine leaving a bur, this can cause a small gap, see #1 above.
So basic maintenance and inspection during the life of the tank helps locate issues, use a magnifying glass when cleaning parts and such regularly, also upon first getting the tank inspect it for machining and manufacturing flaws when first cleaning it before use helps locate this issues before they are a big issue in the first place.
hth.
