How Vapor Is Born

I have seen very different explanations of vapor production on ECF, sometimes quite weird. So, I decided to clarify a bit the process.

Disclaimer: I am not involved in any e-cig research, but I have some background in physics.

Aerosol – a cloud of tiny particles (for us – liquid droplets) in air. Each droplet is too small to be visible individually, but it reflects a tiny amount of light in odd directions and all droplets together look like a cloud or fog (clouds and fog are water aerosol).

Solubility. Solubility could be full (infinite), like PG in VG or alcohol in water, or limited, like salt in water. If solubility is limited, then saturation point exists – excess of salt will not dissolve in water, will stay on the bottom of the cap. If we leave a cap with solution, water will evaporate with time and more and more salt will settle on the bottom (like in Great Salt Lake). The same true for air. For example, water is soluble in air, but its solubility greatly depends on temperature. If after a hot humid day we have a cold night, amount of water which was good for air at high daytime temperature will become excessive for low night temperatures and excess of water dissolved in air should “settle” somehow; the result we usually see is dew or fog.

Human lungs are famous for their wetness and they provide exhaled air with a lot of water in gaseous state at the temperature of a human body. But when a human body is outside at low temperatures exhaled gases (warm air + gaseous water) are chilled and will contain excess of water, which will “settle” as tiny droplets, i.e. aerosol, and we will see clouds of exhaled breath. Nice evaporator, always with us (just add a cold room)…

Boiling. Easy explanation for single liquid system (like water). Heated to boiling point temperature water will boil and produce water vapor. A bit more complicated is boiling of two component liquid, like PG-VG mixture. Liquid will boil as a single system (no separate boiling of its components) at a temperature between boiling points of its components and it will produce vapor of both PG and VG.

Now to vaping. Coil heat liquid supplied by a wick and transfer it into gaseous state (by boiling). But this vaporized liquid can stay in gaseous state only in small area of hot air surrounding a coil. Air draw is chilling this gaseous mixture and PG and VG form tiny aerosol droplets, our beloved clouds.

What’s wrong in my simplified explanations. When multicomponent liquid boils it produces more vapor of its components with lower boiling point, sometimes much more. For example, if we vape 30/70 solution of PG/VG, then PG (boiling point 371 F) will evaporate much faster than VG (477). If things were going as I described above, pretty soon we will be vaping almost pure VG (PG will be gone). It could be even worse. Suppose we have a third component – raspberry ketone (raspberry flavor) with boiling point of just 284 F. It should be gone in no time and most of the tank will be left flavorless.

Fortunately things are a bit more complicated then were described (a bit more complicated than my ability to comprehend them fully). In reality we have a mild overheating and a mild undersupply of liquid by a wick, plus mostly unidirectional liquid movement along a wick. In these conditions boiling produce vapor which is much closer in it composition to composition of a juice.  


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Anybody Use Ispopropyl Alcohol To Clean Coil Heads?

I know the general recommendation is to use Everclear or vodka. I haven't had a drink of alcohol in 22 years, but I see no good reason to keep a bottle of potable liquor around for cleaning my gear if there is reasonable alternative. I just bought a bottle of 70% Isoppropyl alcohol for this purpose from the drugstore. It should be a better solvent than vodka at 140 proof, and it evaporates cleaner than ethyl alcohol. A water rinse should remove any unevaporated alcohol, not that there is much chance of harm from inhaling a miniscule amount of isopropyl. I currently dunk my minipro heads in near boiling water, then rinse in running hot water, which works reasonably well on the exposed wick but probably doesn't do jack for the portion inside the coil.  

Many People Said Like This,

if there is no nicotine, is ecig harmless! right?

but actually that's a definitely wrong info and concept.

e-liquid made by Vegetable glycerin , Propylene glycol , flavor , (nicotine)

so it's not vapor!

you should remind this and also one of ecig's prorperty is absorbing water in your throat thus

u need to drink sufficient water to protect throat.

then if you vape around people, the e-cig smoke can harm other people.

so vapers need to beware these fact well.  

Bottom Coil Compromised Question?

I'm new to vaping. I've went through 3 coils barely using them.


My issue is: When I first install the new coil and add the liquid, it produces vaporizes just fine. It seems like when I set it down for an hour or so, and go back, it still produces good vapor. But after a bit, if I set it down after vaping, and go back, it produced no vapor no matter how much I puff it. It seems like if I unscrew the part where the coil is, and run it under water, and then let it dry, and replace it, then add e juice, it'll start producing vapor again. But it seems like as soon as I set it down for a bit, and pick it back up, there's no vapor and I wash it out again, etc then it works, but eventually just stops producing vapor altogether u til I replace the coil.

What's going on here? am I doing something wrong? Do I need to adjust the coil some how? I've bought brand new coils and barely use them and this happens. Is the coil just getting gummed up? The coils don't make vapor after so long, and the usage doesn't even equate to a full day, maybe an hour or so.  

Longevity Issues With Kanger Dualcoils.

I've had the same exact set up for about a year and a half now. Itaste VTR + Aerotank with 1.5 ohm coils, and i vape at 9.0 watts. I tend to only vape one specific brand/flavor, I'm one of those weird people that just like one thing and stick with it. Up until July last year, i used a local vape shop's liquid. I liked it and it was fantastic. I'm a little fuzzy on their ratio, but I believe it was 70/30 pg/vg. Their liquid would never pool under the coil and my coils would last for over 5 weeks at a time. Then i moved. The cost of their liquid plus shipping was just too high, i was already paying 22 bucks for a 30 ml plus shipping on top of it was just killing my wallet. I found a couple other sources of liquid, one on the net being Apollo ecigs, and the other being local B&M selling VGOD liquid. Both of those i believe are 70/30 vg/pg.

Now since the switch to either of those 2 liquids, my coils are only lasting 5 days tops, and at nearly 2 dollars a pop, its killing my wallet even more than with the liquid i was having shipped here from that local store in FL. What is going on? Is that ratio of VG/PG killing my coils? Its not so much that the coils are burning out, but i just keep having to take a harder and harder draw as the days go on. When its a fresh coil, i get tons of flavor and good vapor, but towards day 4-5, flavor minimizes and vapor decreases. I've soaked them in distilled water and let them dry out, but even that the flavor/vapor tends to peter out after a day or so.

Thoughts?  

My Thoughts About Sub-ohm And Latest Vv/vw Devices...

I've been debating on writing about this topic for a while now, but figured it was time since I've seen quite a bit of posting lately and frankly what I feel is a lot of confusion about the subject.

Let me start off by saying this. This is my opinion and ONLY my opinion. I am basing this on both my own experience as well as my own knowledge given my electrical engineering and information technology background. I'm also a bit of a physics (particle physics as well as general) buff and all around fairly knowledgeable guy. Does that make me an expert on e-cigs? Absolutely not... So again, it's my opinion. It will hopefully seed some food for thought at the very least, and if you downright disagree, then that's your right to have your own opinion as well.

With all that said, let's get started.

Back in the end of August I received my Cloupor T5. This isn't a debate about that device, so let's not go there. I like mine, with the new firmware upgrade. It works wonderfully for what it was designed for. It wasn't the first high power VV/VW mod I owned, but it is the one I generally gravitate towards right now, at least until I make my final decision on which 100W-150W device to buy.

Anyway, I walked into the local B&M one day and one of the guys there was checking it out. He loved the form factor, and was really talking it up seriously considering getting one until he asked how low of a build you could put on it and I mentioned that it goes down to .2 ohm, but it has a 10 amp limit. WHOA!!!!!! Immediately he started trashing it saying he couldn't believe they would "false advertise" something and say it could do 50 (at the time, 75 now) watts when really it couldn't...

No... You don't understand... You don't NEED a .2 ohm build to push high wattage... That's the whole point... The thing can output up to 9.3 volts.... At 9.3 volts that thing can push 75 watts into a 1.1 ohm coil and only push 8 1/2 amps...

"That's crap man... You can't get thick vapor on anything that's not sub-ohm dude..."

I continued to throw "clouds" that dwarfed his... Despite the fact I was running a 1.4 ohm build at 50 watts and he was running a .3 build on his mech which was pushing around the same wattage depending on his battery voltage and voltage drop.

I decided at this point it wasn't worth trying to explain... It seems to me that so many people are wrapped up in this idea that the "clouds" are all completely tied and related to the resistance of their coil(s). Like they are so dependent on one another that there is no other way to see things.

I'm not a "cloud chaser" by any means... But I do love vapor and flavor... I'm more of a flavor chaser than anything.... But in that quest it does mean producing pretty thick and large (that's what she said) clouds.

Again, this is my opinion only, but you guys and gals have GOT to get this idea out of your head that "clouds" or vapor are tied to the resistance. It's just not true.

First of all, there are a LOT of variables that DIRECTLY affect the amount of vapor that's produced, and unfortunately (or rather fortunately) resistance is NOT one of them. Indirectly yes, but not directly.

Vapor, or the production thereof, is a result of the amount of juice that can be vaporized in a given amount of time. It really is that simple. But there's a lot that goes into that.

To vaporize e-juice you must heat it to the point where it vaporizes. In our case, a heating element wrapped into a coil is used to achieve this. The surface of the coil in in contact with the juice and the energy released from the wire in the form of heat in turn heats up the e-juice and vaporizes it.

The surface of the coil? That's right... The key here is surface area... Imagine we had a way to flash heat a metal surface from room temperature to 700 degrees almost instantly. Now if we place a small drop of juice, say 2mm in diameter in the center of this surface and turn it on. That small drop is going to get vaporized almost instantly. The result will be a small puff of vapor. As you would imagine, it won't be a tremendous amount of vapor. Now imagine we rigged up a gravity fed system that would feed juice as fast as it's vaporized... Still though the surface area being used to vaporize is only 1mm in diameter. We turn it on again... What happens? Now we get a stream of vapor... But it's still a very small stream. Sure it keeps going, and overall you're going to end up getting more vapor, but you still aren't going to fill your house with it. BUT... Suppose now we instead place a drop of e-juice that's 20cm in diameter. We've just went from a surface area of 12.57mm2 to 125664mm2! That's a huge difference in surface area... Now what happens when we turn it on? We'll get a GIANT puff of smoke... That's a LOT of juice vaporizing all at one... Now imagine taking it a step further and going back to our gravity fed system, but this time it can supply enough to keep that entire 20cm circle saturated.... We turn it on again... Now we get a giant plume of vapor that's going to fill the house in seconds!

It's surface area that makes the most difference in vaporization... The more surface we have turning juice to vapor the more vapor we can produce.

But, there's still a lot more to it than that when it comes to our e-cigs. First of all, as stated above, you have to keep that juice supplied to the heat source, in this case the surface of our coil. That's where wicking comes in. If your wick isn't good enough to carry a fresh supply of juice as fast as your heat source can vaporize it, then you'll get a nasty burnt dry hit instead of a nice flavorful cloud.

Airflow must be considered. Ever come inside from working in the yard on a hot summers day, covered in sweat and then stood in front of a blowing fan? Best feeling in the world isn't it? That fan is evaporating sweat off your body and carrying away heat with it. Leaving you feeling nice and cool. In the case of our coils, much the same process is taking place. As the juice is vaporized heat is being carried off your coil. However, vapor that's carrying the heat needs to now be carried away... If it's not, then the heat will simply build up. It can't go anywhere and when that happens the amount of heat in a given area (known as the heat flux) increases which results again in a dry nasty burnt hit. Let's back up for a second. Imagine coming in from that yard work and standing in front of the fan, except this time you wrapped up in 5 giant wool blankets first. Not exactly that same wonderful experience is it? You're not getting air flow over your body any more, so the heat is retained. The same happens with our coils.

Now let's talk about heat flux for a moment. Heat flux is the amount of heat being released in a given area. Previously I gave this example. If you take a 5000 watt portable cube heater and place it in the middle of a giant 100' x 100' pole building in the middle of winter, what effect is it going to have? Very very little. It won't warm that building as more heat is escaping than being generated over time and there's such a giant area inside that building that the very small output is going to do nothing. On the other hand, take that same 5000 watt heater and place it inside a 4' x 4' shipping crate and sit inside there with it. Quite a difference huh? It's going to burn you up in no time. You're running the exact same wattage so what gives? That's where heat flux comes in... In your pole building the heat flux was VERY VERY small... On the other hand, in that shipping crate the heat flux was extreme!!!

Our coils and atomizers have heat flux to worry about too. Because the juice vaporizes at a given temperature. Somewhere around 400-500 degrees if I recall. Anything less than that and it won't vaporize... But... There's an important consideration to think about...

How hot is a pot of boiling water? 212 degrees right? But wait... I set my stove on Hi, and the specifications clearly state that should be 500 degrees.... So no, my pot of water is 500 degrees... Um no... Your pot of boiling water is 212 degrees no matter what. Why? Because of what we talking about earlier... As the water boils, the steam carries away heat. It will NEVER reach a temperature above 212 degrees... The more heat you APPLY via the burner, the faster it will boil... The more steam (and therefore heat) is released....

Juice on a coil works exactly the same way. The more heat flux you have, the faster the juice is vaporized and the more that heat is carried away. However there is a big difference between our coils and a pot of water. The water has a large supply. Our coil doesn't. It relies on it being fed via our wick. This is where heat flux and wick come into play. The hotter the heat flux, the more efficient our wick needs to be, otherwise it can't supply enough juice to keep the surface wet. In that cause the heat builds even more and soon you have burning wick, coil, etc.

Airflow is important because without it our heat flux rises, which means our wick has to be even more efficient. No matter how good your wick material is, it can only wick so fast.

Whew......

Got all that so far? Hopefully you have a better understanding of the processes that go on in these remarkable little devices. Let's move on shall we? Let's get to the core of this post, and why you've had to be inundated with all that information.

In the beginning there were mods. Mods were flashlights or just about anything else you can imagine that could be used to power an atomizer. The existing batteries at the time had very small capacities. So with these other devices being utilized it was quickly realized that much larger batteries with higher capacities could be used. Thus "mods" were born.

A mod is really just that... What we these days refer to as a "mechanical mod". A battery and some sort of switch mechanism. This means a FIXED voltage. Now the thing is, with a fixed voltage if I want to produce more watts, and therefore heat, I only have one other variable I can adjust... Resistance.

Soon it was realized that the lower the resistance of the coil, the more wattage was produced, and therefore more heat was released... Meaning a higher heat flux and more juice getting vaporized.

Sub-ohm was born.... As batteries improved and could handle higher and higher currents, lower and lower resistances could be utilized.

This all culminated into the idea that seems to be ingrained in so many's heads to this very day... The lower the resistance, the more vapor I produce. And in the case of a mechanical mod, that's exactly correct.

Early VV and VW devices couldn't handle very much current and/or wattage. So this still held true. If you wanted large clouds of creamy tasty vapor, you needed a mechanical mod with a sub-ohm build.

But more recently there has been a slew of high power regulated mods coming out.

I've recently seen some posts referring to some of the newer regulated devices. Talk of how "stupid" people are going to feel when they get their hands on these things and realize they can't go down to a ridiculously low voltage, or the amp limitations prevent them from running coils of .1 or .2 ohm at full power. Every time I see one of these posts, one half of me laughs and the other half just shakes his head. These people who make such comments just truly don't understand what these devices are all about.

These devices aren't about trying to run a ridiculously low resistance build... They have voltage to spare... They can pump out way more than the 4.2 volts a mech mod is capable of. What does that mean? Well.... Let's remember the above...

It's all about heat flux and surface area... But we know we can "exceed" a certain point where our wicking material just can't keep up with our heat flux. In that case at best we aren't generating vapor as fast as we could, and worst case we get a nasty dry burnt hit full of our burnt wicking material.

Why does that relate? Because in general the lower resistance our build, the less surface area we have. Now, we can work around that, by using a thicker gauge wire. A 24awg build is going to have a lot more coils than a 30awg build given the same resistance..... BUT... what we also have is a lot more metal... Meaning it takes longer to heat up, and also longer to cool down.

Mention a "2 ohm build" to a "cloud chaser" and he'll laugh at you... Because in his mind he imagines this clearomizer type build running a few watts producing almost no vapor at all... That's because in his mind when you talk about a 2 ohm build he's thinking about supplying it with a maximum of 4.2 volts... Which means almost 9 watts...

But suppose you took that same 2 ohm build and ran 9 volts into it? All of a sudden you're kicking out 40 watts of power. And spreading that 40 watts out over a large surface area...

Starting to get the picture?

Let's say we build a .4 ohm build with dual 24awg coils... That's 11 wraps on each coil with a 2mm inner diameter... That's 44 watts on a freshly charged battery with a drop to 27 watts by the time the battery reaches 3.3 volts. (This is NOT accounting for voltage drop in the mod itself) But at 44 watts that's a heat flux of 243mW/mm2.

There are two problems with this build... First, it's going to take a VERY long time to heat up... From the time the switch is thrown till it's ready to vape is going to be a while. That's a lot of metal for 4.2 volts to handle... Likewise, once the switch is thrown back off, it's going to continue to cook juice for a while... It's going to take a good bit for it to cool back down... Which means a lot of excess wasted juice and longer run times meaning lowering of battery life. Second, it's not consistent. Every hit drains the battery and results in a lower voltage. The more hits, the lower the voltage. That means not only is it taking even LONGER to heat up, which means even more battery drain, but not as many watts are going into the coil, so less vapor is being produced with each hit.

Too many times people who build for mech mods try to build the same way for regulated mods. They are different animals. They aren't designed to run the same sorts of builds. It's my belief this is where so much confusion comes in.

But let's say instead we build for a regulated mod. Like the T5 for instance. Now in this case let's say we build a 1.8 ohm build with dual 29awg coils... That's a whooping 19 wraps on each coil at 2mm inner diameter... Now we can run this setup at 8.9 volts to get the same 44 watts we were kicking on a fully charged battery with our mech's .4 build. But what's the difference?

Well... LOTS of difference.... First, since we're using a regulated device that voltage is going to stay at 8.9 volts for the entire ride... From first hit to last it's going to perform exactly the same way... As the battery voltage drops, the boost circuit in the DC to DC will simply draw more current from the battery and "Trade" it for the voltage it needs...

Second, we have less than HALF the heat capacity in the wire... In other words, the lag time from when it's fired to when it's fully heated, and vice versa, when it's stopped and cools down is WAY less than the 24awg build... Because we have less mass to heat and cool.

Third, we have MUCHO surface area... Remember how we learned how important surface area is to vapor production? Well now we've got tons of it... almost 40 wraps worth!

And as for heat flux? We actually have an even higher heat flux on this build at 307mW/mm2... So that larger surface area is being delivered more heat within it than our mech build. As long as our airflow and wick can keep up, we're going to be producing large amounts of vapor...

Starting to see the light? Look, I'm not trashing mech mods here... I have some and use them myself... They are simplistic and small and can give a darn good vape with the right setup... Instead what I'm saying is, the newer regulated devices are being "compared" to these mech's by mech users, and often times being trashed because they can't do .0000001 ohm builds... (some exaggeration inserted.) But these folks just don't realize that that is NOT what they are intended to do. Many of them I don't think even realize WHY they build the sub-ohm builds the run... They don't understand that it's to overcome the limitations their mech mod presents them, and instead think that somehow there's this magical formula that says the lower resistance you can build the better the vape... and that's just bull...

With higher voltages you can build higher resistance builds with much more surface area and good heat flux to produce massive amounts of vapor with absolute consistency. And that my friends is exactly where these high voltage regulated mods shine.

I'll climb off my soap box now....


TL/DR: The delayed choice quantum eraser experiment is super cool!!!  

Water

I know the topic of how to get VG film off glass surfaces has been well explored in past threads. But I just "discovered " by rinsing my reading glasses off in plain tap water and a good wipe dry with a paper towel that water will clean it. I'm gonna do that to my car if I ever get out of the house long enough to do something useful. I've tried various glass cleaners and they never seem to get it all. But water did on my glasses so...just a thought..  

So For The First Time I Boiled Cotton

As the title says never thought that boiling really would make that much of a difference but the first wick I've made with it is like a dream with so much better taste and its been wicking so much better, has anyone else had this same experiencing after boiling for the first time or did I just get lucky at making a perfect wick on the first piece i used from the batch.  

What Is Best Besides Water To Keep You Hydrated?

I can't make myself drink water and coconut water taste like dirt to me. What else is good to keep you hydrated?  

I Am Always Super Thirsty... Help

My stats:
I vape .5 ohm, with dual coils
I vape 6 mg nic
I vape around 25-30w

I've been home sick so I've been vaping a lot more than usual. Even when I'm at work, I drink a lot of water. I am just constantly thirsty.

I also take medications for bipolar disorder and mood stabilizers. I don't think these have anything to do with it.

Either way I am going through water and pissing like crazy. And not just water, milk, pop too.

Help?  

Ecigintelligence 'bits & Bytes'

This is part of an newsletter email:
Q: Do the words used to describe vaping alter perceptions of risk?

A: At first sight, the two headlines appear very similar: “Labeling e-cigarette emissions as ‘chemicals’ or ‘aerosols’ increases the perceived risk of exposure” and “Accurate labels like ‘aerosol’ or ‘chemicals’ increase perceived risks of e-cigarette use”. The ironic thing is that while both fairly accurately reflect the study being reported, one – the one that uses the word “Accurate” – is not quite so, well... accurate.

As any chemistry teacher will tell you, everything is composed of chemicals – you are, your food is, the screen you’re reading this on is made up entirely of chemicals. Which makes the labelling of e-cig vapour as “chemicals” self-evidently true at one level, but deliberately misleading at another. (Don’t drink that water, it’s nothing but chemicals!)

As it turns out, those headlines – one from News-Medical.net, the other from Medical Xpress – are placed over identical reports (i.e. an uncritically reproduced press release) of a study published this week in the Journal of American College Health. And the very title of that study, “Aerosol, vapor, or chemicals? College student perceptions of harm from electronic cigarettes and support for a tobacco-free campus policy”, tells you at once that this is hardly unbiased science, seeking answers not yet known, but rather that sadly common form of pseudo-science that starts out with its conclusion in place and sets out to “prove” it.

The study of college students in 2018 and 2019 found – not altogether surprisingly – that those asked to assess the harmfulness of secondhand “aerosol” or “chemicals” emitted by e-cigarettes were more inclined to see them as dangerous than those who were asked to assess “vapor”.

It also found, unsurprisingly, that they were around twice as likely to support a tobacco-free campus policy. This being the US, where authority routinely seems to miss the point that e-cigarettes don’t contain tobacco, we can take that to mean a vape-free campus policy too. Which, it is not hard to assume, is exactly what the researchers wanted them to support.

The study’s conclusion is itself a masterpiece of deception (perhaps self-deception). It is this: “Health campaigns should use accurate terminology to describe e-cigarette emissions, rather than jargon that conveys lower risk.”

Just how the term “chemicals” – which, after all, encompasses every breath you take – is more “accurate” than “vapor” the authors make no attempt to explain.

Now it may be true that much research which purports to support e-cigarette use is equally tendentious, setting out with its conclusion already prepared. But to respond with such blatantly bad science is no help to anyone who really wants to discover facts as yet unknown. And there are plenty of those yet to be discovered in the field of vaping.

Oh, and the answer to the question posed above is: “Yes, of course”.
Click to expand...

This is a link to the study mentioned.
https://www.tandfonline.com/doi/full/10.1080/07448481.2020.1819293