Coil gunk is an e-cigarette problem that many e-smokers know all too well. How many times have you experienced this scenario? You’ve been using your favorite sweet and creamy e-liquid non-stop for a few days, and you begin to notice a change in the flavor. You ignore it at first, but before long, it tastes like you’re getting dry hits even though your tank is full or your wick is yet. You look at your atomizer coil, and this is what you see:

Pretty gross, right? There are quite a few factors that contribute to atomizer coil gunk. No atomizer coil lasts forever, but there are some conditions that contribute to rapid coil gunk buildup. The good news is that those conditions are, for the most part, completely avoidable — a good thing if you’re using a tank with pre-made coils and can’t afford to drop a new coil in your tank every day. Ready to learn more about coil gunk and decide on a plan of action? Read on!

What Is Coil Gunk?

Coil gunk is a dark crust that forms on an atomizer coil, eventually discoloring the wick as well. Eventually, the crust becomes so thick that you can taste it when you vape — most likely because the coil is actually burning some of the gunk off. After a while, coil gunk makes the experience of vaping so unpleasant that you have no choice but to replace or clean the coil.

Quite simply, coil gunk is residue. It’s all of the stuff in your e-liquid that doesn’t vaporize cleanly — flavors, sweeteners and other components. Eventually, it claims every coil. Today, though, coil gunk accumulates more quickly than ever. For that, you can blame the sweet, rich e-liquids that many e-smokers prefer today. You can also blame the popularity of sub-ohm tanks and rebuildable atomizers (RBAs) that consume more e-liquid than ever.

If you have an e-liquid that tastes exactly like your favorite dessert — and it’s so sweet and irresistible that you can’t put it down — it probably causes coil gunk. I’ve had pre-built coils gunk up after less than a full day of use. At $2-3 per coil, that’s not a lot of fun. If coil gunk is getting you down, read on to learn about some of the most common causes. You can decide for yourself whether changing your vaping habits in an effort to reduce coil gunk would be worthwhile.

What Causes Coil Gunk?

Sweeteners

By far, sweeteners cause more coil gunk than anything else. The carbohydrates and sugars don’t fully vaporize; instead, they collect on the coil and eventually burn. If  you want to avoid a gunked up coil, the absolute best thing that you can do is avoid any e-liquid with sweeteners.

Take a look at the video above, in which someone drops a red hot ball of nickel into a pan of sucralose (Splenda). You might think that a glowing ball of nickel and an atomizer coil have nothing in common with one another — until you watch the video and see that, when they pull the ball out, what’s on it looks an awful lot like coil gunk.

By far, sweeteners cause coil gunk more rapidly than anything else.

I’ve noticed that Black Note and Halo e-liquids, in particular, seem to cause far less gunk than a lot of products from other e-liquid companies. In Halo’s case, I believe it is because Halo e-liquids contain less sweeteners than other brands — and often no sweetener at all. Black Note is a very gunk-free e-liquid simply because the tobacco extracts are so well filtered and few additional ingredients are added to their e-liquids.

I know, I know. Sweet e-liquids are very tasty. I love my Mad Hatter e-liquid, too. I’m just saying that if you prefer really sweet e-liquids, you’re probably best off using a tank or atomizer that you can rebuild — or at least re-wick — because you’re going to get coil gunk really quickly.

High Wattage, Chain Vaping

Do you enjoy taking very long puffs when you vape — particularly at fairly high wattage settings? You might think that you have a problem with coil gunk, but the problem may actually be that you’re burning your wick. If you use cotton, for example, it’s important to bear in mind that cotton is exceptionally absorbent — but it doesn’t wick very well. In other words, liquid might not travel to the coil as quickly as the coil can vaporize it. Take enough long puffs consecutively, and your wick will at least partially dry out. You’ll burn your wick away, little by little.

If you have an RBA or RTA, It’s actually really easy to tell if you’re vaping too frequently and killing your wick. Simply access the coil and tug one side of the wick with a pair of tweezers. The wick will break easily, and you’ll see a big black spot in the portion of the wick that was directly under the center of the coil. Take a look at the picture below:

In this picture, you can plainly see that the cotton wick has split in the middle from burning.

If you’re using a tank system, it’s not so easy to tell whether you’re killing your wick. It’s probably safe to assume that you are, though, if you need to replace your coil every day. If you look inside your coil and see black after just a day of use, that’s another likely sign.

NET E-Liquids

I have experience with two types of Naturally Extracted Tobacco e-liquids — Black Note and everything else. Most of the time, an NET e-liquid has a very noticeable “ashtray” taste. That’s because all of the tiny tobacco solids in the extract weren’t filtered out. Those solids end up sticking to the coil and burning. Eventually, the burned tobacco solids form a crust of carbon on the coil. The coil gunk spreads and discolors the wick, and eventually you’ve got a foul tasting e-cigarette.

What can you do about a crusty coil caused by NET e-liquids? In my opinion, you should give Black Note a try. Black Note makes the only NET e-liquids I know of that don’t form coil gunk.

VG-Based E-Liquids

If you’ve done any reading online about coil gunk before coming here, you’ve probably seen someone claim that an e-liquid with a VG/PG ratio that heavily flavor vegetable glycerin will cause coil gunk more quickly than other e-liquid formulations. I haven’t seen that, myself. I actually have no reason to believe that vegetable glycerin causes coil gunk. However, it is true that VG doesn’t carry flavors as well as PG. For that reason, some vendors add extra flavor to their “Max VG” e-liquids. If you consume more flavoring agents, you’re going to get coil gunk more quickly.

Dark E-Liquids

Some people find that darker e-liquids cause coil gunk more quickly than clear e-liquids. I have no opinion on the matter because I find that dark e-liquids are almost always sweet — and it’s well known that sweet e-liquids cause coil gunk more quickly than anything else. I find that very sweet e-liquids gunk coils up at about the same rate regardless of their color. It could be, though, that the same compounds that make some e-liquids darker than others also collect on coils rather than vaporizing fully.

How to Fix Coil Gunk

Clean Your Coil

Most of the people reading this article probably use tank systems with pre-built atomizer coils. It is technically possible to re-wick and dry burn a pre-made coil, but doing so is often difficult. You really won’t get anything like the performance of a new coil unless you replace the gunky coil entirely. If your wick isn’t burned at all, though, you may be able to restore some of the lost performance by cleaning your coil.

To attempt cleaning your coil, I suggest swishing it in a strong grain alcohol — something that’s safe to drink. If you have a very small nylon brush, you could also try scrubbing the inside of the coil. Rinse the coil with very hot water, and leave it out to dry completely before priming it with e-liquid and attempting to use it again. Usually, the same conditions that cause coil gunk also ruin cotton wicks. So, although you can try cleaning your pre-built coils, you may have limited success. Still, it’s worth a try if gunk has ruined your last coil.

Switch to a Rebuildable Atomizer

If you deal with coil gunk constantly and don’t want to change your usual e-liquid, you should probably consider using a rebuildable atomizer. Pre-made coils for tank systems usually cost about $2-3 each. To a certain extent, coil gunk is simply a function of the amount of e-liquid you consume. So, if you’re replacing your coil every couple of days and going through 10-15 ml of e-liquid daily, you could easily end up paying more for vaping than you would for smoking.

Switch to a rebuildable atomizer, and you’ll cut your costs significantly. Instead of spending a few dollars for each new coil, you’ll spend a few cents. With a rebuildable atomizer, it’s also much easier to clean the coil and put in a new wick — which is really all that you need to do to get rid of coil gunk.

It’s finicky and sometimes frustrating, but I’ve really been enjoying the iJoy Tornado Nano recently.

Change Wick Material

If you’re constantly torching your wick by vaping at high wattage settings or not giving your coil a sufficient break between buffs, you may benefit from a switch to a different coil material. People love cotton because it’s cheap, it works fairly well as a wick and the flavor quality is high. One thing cotton isn’t good at, though, is staying intact at extremely high temperatures. You may have a better experience if you switch to a different wick material such as silica or ceramic, since both of those materials can handle high coil temperatures without burning.

Re-Wick and Clean

If you’ve never cleaned a gunky RBA or rebuildable tank atomizer (RTA) coil before, it’s really not so hard to do — but there are several ways to go about it. The first thing you’ll want to do is remove your wick, assuming that you’re using cotton. Whether it’s from the coil gunk or constant vaping, the wick is going to be scorched, discolored and unusable. So, you’ll need to remove it and throw it away. I like to disassemble my RBAs and RTAs fully and rinse them in the sink before I begin, since I don’t like getting e-liquid on my hands and re-wicking a coil is always a good excuse to give everything a good cleaning.

Use your fingers or a pair of tweezers to gently tug the wick out of the coil. Throw the wick away.

That’s the one aspect of cleaning a gunky coil that pretty much everyone agrees on. You need to get rid of the wick. The best way to clean a gunky coil is a subject of intense debate, though, so I’ll provide a few options and let you select one for yourself.

Dry Burn

Probably the most popular method of cleaning coil gunk is the dry burn. To dry burn your coil, simply pulse the fire button a few seconds at a time until the coil begins to glow red. During the dry burn, the coil burns away the gunk. You should be left with nothing but dark carbon on your coil after dry burning, and you can get rid that by rubbing the coil with a wet cotton swab, using a small brush or running some water over the coil. Once the coil is completely clean, you can add a new wick and continue vaping.

What are the downsides of dry burning a coil? For one, you are actually burning something. That’s going to create fumes, and you might inhale those fumes. Nobody actually knows what the implications of that are.

There’s also the possibility of a coil breaking and potentially causing a short if you heat it too much. I actually ruined a very nice regulated box mod that way. The coil popped, the mod made a sort of screeching sound, and then the screen turned off. Obviously, that was a potentially dangerous scenario. I learned that day that a dull red glow on the coil is perfectly sufficient when dry burning.

Lastly, you should know that some types of wire don’t really take well to dry burning. Titanium, nickel and nichrome all have potential issues associated with dry burning. Unless you use a Kanthal coil, I’d really suggest cleaning the coil in some other way.

Liquid Cleaning

You can actually do a lot to de-gunk your coils simply by using a bit of liquid. After removing the wick, unscrew the coils from their posts and drop them in some very hot water. After a bit of time, the coil gunk will start to fall off. If necessary, you can give it a bit of mechanical help with a brush or cotton swab.

You can often dunk the entire atomizer base — coils, build deck and all — in liquids without worrying if you don’t want to bother with reattaching the coils when you’re done. You might want to be careful, though, with metals such as copper that discolor easily.

Some people suggest using other liquids such as vodka, grain alcohol or Coca-Cola for cleaning coil gunk. It seems to me that an alcohol that’s safe to drink is acceptable as a coil cleaning solution. I use that method sometimes, myself. The Coca-Cola method supposedly works very well, thanks to the acids in the beverage. However, the same acids that eat away the gunk on your coil could potentially eat away at and degrade the coil itself. Doesn’t sound like a great idea to me.

Ultrasonic Cleaning

Do you have an ultrasonic jewelry cleaner? If you do, fill it with plain water and drop in your coils. The ultrasonic waves provide plenty of mechanical help for removing coil gunk, and you don’t need to worry about residues since it only requires water.

Clean All of the Coil Gunk

Whatever method you use, the most important thing is that you clean away all of the residue on a coil before using it again. Otherwise, the residue that’s left will burn, the wick will degrade almost immediately and you’ll need to start the cleaning process all over again.

Re-Wicking Pre-Built Atomizers

It is actually possible to re-wick a pre-built atomizer head, as evidenced by the picture above. Whether you can do it easily, though, depends on the atomizer’s design. With some atomizer heads, you can simply pull the pin and insulator off of the bottom and push the coil and wick through the top. Unwrap the wick from the coil, replace it with a new wick and reassemble the atomizer. Make certain that you return the coil’s positive and negative leads to their original positions. One is usually slightly longer than the other; that one goes between the pin and insulator. The shorter lead goes between the insulator and the body of the atomizer.