Rebuildable tank atomizers (RTAs) can be annoying. The concept is so good – the performance of an RDA with the convenience of a tank – but in practice many vapers end up getting dry hits with RTAs. There could be many reasons for this, but most issues ultimately come down to wicking. Unlike with pre-made coils, which can be carefully designed and built to ensure consistent performance, RTAs depend on you to produce a reliable setup. This gives many RTAs a steep learning curve, and while we can’t write an RTA wicking guide for every single device, there are several general tips that can help you get your RTA wicking correctly regardless of the specific model.
The Background: Understanding Dry Hits
Before discussing tips for preventing dry hits with RTAs, it’s important to understand what causes a dry hit. The name really gives it away: it’s when you try to take a hit but there isn’t enough liquid in the wick (i.e. the wick is dry). This might happen if you try to vape before your wick has had time to absorb enough e-juice, and it might happen if you “chain vape” and vaporize too much e-liquid without giving the wick chance to replenish itself.
When it comes to dry hits for RTAs, though, the most common problem is that the wick itself isn’t set up to allow the easy flow of e-juice. It could be that the chamber is trapping and compressing the wick or that the wick itself is too dense to allow e-juice to efficiently soak into it. This is especially likely if you’re using high-VG e-juice, which many vapers who use rebuildables do. Black Note’s e-juice is 50/50 PG/VG, so it’s much more forgiving for wicking than many higher-VG e-juices, but the same general principles apply whatever you’re vaping.
1 – Keep Your Cotton Fluffy
One of the most important things to keep in mind is that densely-packed cotton won’t soak e-juice up as effectively as a more loosely-packed wick. There are a couple of different strategies used to accomplish this, but the key point is that you want to avoid compressing your wick too much at any stage in the process (with the exception of making a point at one end when you’re inserting it through the coil).
If you’re using Japanese organic cotton, the best advice for keeping it fluffy is to remove the outer, flattened layers to expose the fluffier material inside. The sheet will still keep its structure, but it will make it easier to avoid compressing the wick too much while inserting or positioning it.
An alternative technique that works for any type of wick is called the “Scottish roll.” You spread your section of cotton out on a flat surface – pulling it perpendicularly to the grain of the cotton – so that you can see the surface between the strands. Then you simply roll the wick back up into a tube shape, just enough to keep its shape but not so tightly that the wick becomes dense.
These two approaches will go a long way to preventing wicking problems because it’s packed too tightly, but you should stay mindful of this risk throughout your build.
2 – Think About Your PG/VG Ratio and Don’t Use Too Much Cotton
If you use too much cotton for your wick, it’s much harder to ensure it doesn’t end up too dense to wick effectively. This is often a matter of trial and error more than anything (and if you’ve used an RDA before you should have a good idea of how much to go with), but in general you want the wick to fit in the coil snugly without being so tight that it’s hard to insert without misshaping the coil.
However, the amount of cotton you need to use is closely-related to the PG/VG ratio of the juice you’ll be vaping. For higher-VG mixes, less cotton is better. This is because VG is thicker than PG, and so needs more “space” in your wick to soak up into – a little bit like how you might be able to drink coke through a straw easily but would struggle to enjoy a thick milkshake through it.
If you have a higher-PG blend (like Black Note’s 50/50 mixes), then you can afford to have a little bit more cotton packed a little more densely. You still should be able to insert the finished wick into the coil without misshaping it, but you don’t have to be as strict about the amounts.
As a general rule, try to make your chunk of cotton just a little bit thicker than the diameter of your coil when it’s as fluffed up as it will be in use.
3 – Give Your Wick a “Bowl Haircut” Around the RTA Deck
The biggest challenge for RTA wicking is cutting the wicks down so they reach the juice channels without blocking them up. While there are a few different schools of thought on this, the easiest advice is to give your wick a “bowl cut” (like you may have gotten from a lazy hairdresser as a kid) around the base of your RTA deck.
With your wick inserted in your coil, stretch the ends out so the wick is horizontal. Get a pair of scissors and get ready to cut. Looking down from above, you should be able to see the outline of the circular RTA deck and your wicks stretching out beyond it. The trick is to follow the curve of the RTA’s deck as you cut your wicks. This leaves different parts of your wick different lengths (which may feel inherently wrong if you’re like me and want everything neat and even) so that none of the wick protrudes over the edge of the deck. You don’t have to be absolutely precise about this, but it’s worth taking time to get it close.
Some vapers leave the wick a little longer, so that the longest part of the wick would reach down into the juice channel for the RTA, but the advice above still captures the basics. The only difference is that you let the cotton overshoot the edge of the deck when using this method, but you still snip them in a curve that follows the shape of the deck.
4 – Don’t Block the Juice Channels With Your Cotton
After cutting your cotton down to size, you’re ready to start putting the wicks in position. If you’ve gone with the method suggested in the previous section (cutting the wick around the edges of the deck), the goal is to place the wick so it sits on the opening to the juice channel without being stuffed into it. The wick should be like a cap on the juice channel, not like something stuffed down into it, and the shape you’ve cut it into should help a lot with this. Remember to be gentle when positioning the wicks, though, so you don’t make them too dense to soak up juice effectively.
If you’ve used the alternate method (where the wicks overhang the deck a little), you can have the longer part of each wick end actually in the channel. The key point is that it is just a small portion of the wick extending into the channel, rather than the whole thing blocking it up entirely. You need to leave plenty of room for your e-juice to get up to the chamber. Most of the wick (or at least half) should be sitting at the top of the channel on the main deck.
Generally it’s easier to get your wicks in place if you manually soak them with e-juice first, but this isn’t strictly necessary.
5 – Keep Your Cotton Away from the Airhole
Although this is more to avoid leaking than dry hits, most RTAs have under-coil airflow which can be prone to issues with leaking. Most of the time, this is caused by your wick either dropping down into or being too close to the under-coil airflow, which gives e-juice the opportunity to leak down and seep out of your device’s airholes. The solution to this is simple: using a small tool (a precision screwdriver, pair of tweezers or anything else small and thin) you can nudge and position your wick to ensure it stays clear of the under-coil airflow hole.
6 – Prime Your Wicks Before Refilling and Vaping
If you haven’t applied e-juice to the wicks already, it’s important to do this before you attach the chamber casing and fill your tank. While you could fill your tank without priming your wicks and avoid problems if you give the liquid plenty of time to soak up, if you’re anything like me you won’t be that patient. Take a second and give your wicks a liberal soaking in e-juice prior to filling your tanks and you won’t get a dry hit as soon as you start vaping and ruin your hard work.
7 – Attach the Chamber Carefully and Make Finishing Touches (Without Compressing the Wick)
When you’ve wicked your coil and primed it, all you have to do is screw on the chamber. This can go wrong sometimes if your wick overhangs your deck, because it can get trapped in the threading or compressed during the process. If you’ve followed the other tips, this should be easy to avoid, but this is something to pay attention to when you’re screwing the chamber cap back onto the deck.
Traverse the Learning Curve and Enjoy Your RTA
It’s clear that sub ohm tanks are much simpler from the end-user’s perspective in comparison to RTAs. If you want a solid vaping experience without the effort, there are many options. But for many of us, pushing through the learning curve with RTAs is well worth the effort. You can get exceptional performance at a fraction of the running cost. All you have to do is follow the tips in this post and give yourself some hands-on practice and you’ll be wicking your RTA like a pro in no time.