UPDATE: This apparently works equally well with the Kanger Protank, and other Kanger BCCs with the silicone caps on the atomizer heads. If you’re having issues with those leaking or gurgling, you may want to give this a shot.
A while back I ordered a couple of Kanger EVODs because I wanted something slim for my on the go kit, and the Protank mini was not yet available (I now have two on their way to me).
I’d heard nothing but good things about them, and figured that since they can use the same heads as the Protank, I’d only have to keep one type of head on hand.
They are a great vape. Until they leak/gurgle.
At first I thought it was because I was vaping in +100F temperatures, but even in my 72F house, once I got below about 1/2 a tank the gurgling would start. Then the leaking starts.
Ok look, a quarter ml of juice sitting on top of my battery. Lovely.
At first I thought the problem was with the head. I swapped out the head with a new one from a different package. No dice, exact same problem.
I looked at the bottom of the unit, and the leak was coming through the bottom of the positive contact pin. That precludes the base to head fit being the issue (since the area where they mate was pretty dry).
I thought, well maybe I just got a defective unit. These things are mass produced in China after all, it happens. I tried the other unopened EVOD. Same result. Grrr.
So I took to the internets.
Didn’t really find anything. I found a couple of people complaining about leaking, and others having no issues at all. I deduce from the number of posts I found where people are warning about gurgling after half empty (and saying that just topping off fixes it), that this is a common problem.
I saw multiple comments saying that the juice level dropping below a certain point breaks the vacuum in the tank and causes the gurgling (I also experienced what I would call flooding). I know a little bit about fluid dynamics, and while it sounds good in theory, I’m not convinced that this is the problem. See the fact that there is a hole running through the bottom of the atomizer head into the unsealed battery connection kind of precludes a true vacuum from being present, it’s more of a surface tension effect at that point (but that’s kind of nitpicking). Still, with the viscosity of the juice, and the wick sitting across the top of the hole, and the size of the hole, it should work.
So I disassembled one.
I was sure that either the wick or the press fit between the base and the chimney was the culprit.
When I pulled the chimney off, I thought I had found the culprit. The “flavor wicks” that are set on top of the wick with the coil on it in these things are tiny! It was like two little strands of wick, not even an entire wick.
So I looked in my box of parts, and decided to replace the flavor wicks with a single piece of 2.5mm silica (I wanted to use 2mm, but I didn’t have any).
I trimmed the wick to fit, rinsed the whole thing off, filled the EVOD, and put everything back together.
Holy hell the vapor production improved ten fold! Well ok, that certainly had an effect, but did it fix the leak? It took me a while to get low enough in the tank to find out (if I had some 0mg nicotine juice I could have got there much quicker, but all I have is 24mg and 12mg at the moment). I got a hint of a gurgle, and then a mouth full of juice. Took the head off, and now there is like 3/4 of a ml of juice sitting on top of the battery.
Well it did much improve the juice intake.
So I took it all apart again. This time I paid very close attention to the press fit of the chimney and the base. It was pretty dry. I was thinking about the silicone cap and why it would be there. At first I thought it was there to seal the press fit, but looking at the press fit and how hard it is to pull the chimney off I don’t think that is it’s sole purpose. I think it is to seal the connection between the chimney and the stem inside the EVOD as well.
So I took a pair of tweezers and stuffed the cap on the stem inside the EVOD (it was essentially sitting upside down in relation to how it sits on the stem.
The ‘cup’ portion of the cap had to stretch a little bit to fit over the stem. Hmm. I wonder if the cap is just not thick enough to seal the gap between the bottom of the stem and the top of the atomizer head?
So I flipped it over on the head. It looks like this:
It doesn’t cover the press fit between the atomizer head and the base like this, but I have a back up plan if this doesn’t work.
I filled the EVOD up and installed the head with the silicone cap upside down, being careful to seat the cap over the stem in the top of the EVOD before screwing it down all the way.
I went through an entire tank, down to where I could taste the wick drying out from lack of juice. No leak. It did gurgle a little bit, but I’m pretty sure that is because I let too much condensation build up inside the tip (I was vaping with my mouth only and just immediately blowing it out as fast as I could because I wanted to get it down to where it should gurgle and flood.
NOTE: I used the head that I had replaced the flavor wick with 2.5mm silica for these tests. That may have an impact on the results. I plan to do this with all my EVOD heads as the increased vapor production is great, but I will test it on the next one without doing so first. If that changes the results, I will note that here.
So why does this work?
My theory is that the silicone cap isn’t there to cover the press fit at all (the press fit is tight enough that it’s not going to leak from there). It is there to seal the gap between the chimney and the stem on the inside of the EVOD.
As I mentioned earlier, these things are mass produced in China, and due to the fairly intricate nature of the design and the small size, it is reasonable to assume that the stem on the inside of the top of the EVOD is machined a bit shorter than it should be to ensure a good fit with a bit of ‘wiggle room’ so to speak) for variance in manufacturing tolerance between it and the heads/bases.
Just flipping the silicone cap worked for one of my EVODs, but did not work for the other (apparently the stem is just a hair too short on that one. Time to try out plan B from my earlier experiment. You are going to need an extra silicone cap for this. I took one from a spare head, but I will start saving the reusable parts from heads in the future:
Now take that second cap and put it on the head upside down. It’ll look something like this:
Time to fill her up and try it again.
I was able to get the base screwed down almost all the way (don’t force it or you risk breaking the top of the EVOD). Mine had just a hairsbreadth of a gap between the base and the top piece, plenty of room for the silicone o-ring inside the base to seal it up nice and tight.
Worked perfectly. No gurgles, no flooding (this time I wiped down the tip with a napkin when the condensation got built up), no leaking.
This is an easy fix; Kanger needs to make the top of this silicon cap just a hair thicker. Or maybe make the ‘cup’ part double sided. Either should work and is a really cheap solution to this occasional problem.
If I could not have gotten this fixed, I would never buy another EVOD, and this post would have been a review of the EVOD telling people not to waste their money.
As it stands, I’m ok with it. The EVOD works fantastically after this simple modification, and even better with the larger flavor wick.