Bottom coil Tanks are really better for keeping a wick wet but at times, you still can get dry hits from them. There are many reasons why including the thickness of your juice, wick size and vaping voltage. There have been many suggestions I’ve seen but none seem to work as well as what I’m going to lay out for you and it’s really, really simple.
You see, there is a design flaw in every single bottom coil tank that no company or person has addressed. What makes me so smart? I own a bunch of bottom coil tanks from many different companies and all exhibit the same issues, dry hits every now and then. I set out to figure out why. After studying the design of the BCCs, it became obvious. Pure physics. Liquid physics to be exact.
Here is the issue. As you draw on the mouth piece of a bottom coil atomizer (BCC for short), you are sucking out the juice from the tank basically into the atomizer wick holes. As you deplete the juice in the tank, you are creating a vacuum above the liquid. The more liquid you use up, the more vacuum you create in the tank above the juice. This vacuum wants to keep the juice in the tank and not let it go out through the atomizer wick holes. What happens next, a dry drag into your throat.
Tank designers should have thought about this. Gas cans have a second hole to allow air in to replace the vacuum. They are now even telling you to put a second hole in a can of beer to make it pour better. The same physics happen with your ecig tank.
You can’t just drill a hole in the top of the tank to let air in. Your juice will leak out if tipped. What I do is very simple. Just unscrew your BCC tank from your battery, turn it upside down like you are going to fill it. Unscrew the bottom to let some air in then screw it back. Put it back on your battery and you are ready to go. No dry hits for a while. It’s that simple. Vaccuum is relieved and you are ready to vape for another round without dry hits.
I’m not sure why the tank designers are ignoring this but letting air into the top of the tank while your juice gets depleted should be part of the deisgn. This also goes for carto tanks as well. Clearomizers with a top wick suffer from other issues other than this issue and have thier own.
Just letting air into the tank to relieve the vaccuum will keep you a happy vapor for a long time to come until someone designs a one way air valve into our tanks.
Note – If you still are getting dry hits from your BCC tank after letting air in, you may have other issues like too much voltage for the atty ohms you are using. Use a coil with higher ohms. Also, your juice may be too think for the wick in your tank. This happens a lot and you may need to remove a strand or two from the atty silica wick by pulling a strand out with tweezers. The vaccuum relief method works for me every time though .