Okay. I'll give an engineer, nurse and vapor's take on the matter...
I'm not against sub-ohm vaping. I *am* against the notion that Joe Newcomer with less than second hand knowledge and a few months experience should be doing it to "chase clouds". It really bothers me to see these folks building cloud machines. Sure, the basics are easy, but the risks and consequences are not. Sure, whatever works is a great line, but that ends at the point where you increase the risk of harm to others. In the present environment, harm to others includes your fellow vapers because if regulations so severely limit our ability to vape responsibly then we diminish the ability to save more lives from the known hazards of burning tobacco. That must be the most important consideration of EVERY vaper.
I get it. I really do. I run a 0.7ohm dual coil build in a Patriot daily. I've built quads down to 0.15 and done some fun things with 26 and 24ga Kanthal. I found what works for me and what's fun. I don't make the mistake of thinking that doing huge clouds is without risk to me, my devices and the image of vaping. Hence, you'll only find me pulling out the big guns in a vape shop or meet where I can be certain that the stunt is appreciated. And it *is* a stunt for me. At the very most it is friendly competition.
I've trained myself, using an incentive spirometer to "lung hit' 3 liters of vapor, I've built a couple setups that can deliver. I use 0mg 20/80 unflavored PG/VG. Why? I'm not interested in packing anything that dense with flavor or nicotine into my lungs. We *know* what the mass spectrometry / gas chromatography says about the vapor from some of the early devices. We do NOT know what the data is on these billowy clouds of flavor & nic'd juice. That's a safety issue.
It is a public relations issue too. Let some govt mule get hold of an assay of one the the clouds and find that there's 10% of the harmful stuff from cigarettes and just try to justify it to regulators that there's lower risk. They'll hear none of it because the only numbers they care about is public perception (votes). Once the headline reads "Electronic cigarettes not as safe as first thought" its over kids. We will become outcasts. Sure some of us like to think of ourselves as rebels, but the vast majority of the vaping population do not. They're just trying to stop smoking burning tobacco leaf to ward off dying of cancer or the unpleasantness of living with COPD or watching their wallet empty ever faster into the tax man's coffers. They're the ones who will be harmed and that is a safety issue.
Now add to that the fact that the FDA gets adverse event reports from the public on e-cigarettes already, including potential allergic reactions, battery explosions, burns and whatnot. Let a news story or two happen about a teenager (sorry all 18-19 year-olds you're still teenagers in the media) who does something to him or herself trying to chase clouds because they (like me at that age) think they are all 10ft tall and bullet-proof and it will start another fire storm. It won't matter if it's a mechanical issue or a poisoning issue. Witness the fire storm in NY over eliquids because an irresponsible vaper made it possible for a child to poison itself. That poses a safety risk to the community of vapors.
Now, for battery safety. I've seen the snippet of a chinese-english manual but I have not seen the whole document (I have one on order). I have looked at the published data for the Sony VTC-4 and VTC-5 and the monographs and ratings do NOT demonstrate the testing at the loads the snippet shows for
long term use. As an engineer, I implicitly understand that manufacturers rate their products for performance, longevity and safety. I get it. And I know what we do with these batteries in NOT within the safe and intended use the manufacturer rates them at. I understand things like the snippet exist to give engineers like me an idea of the design limits so that if I must exceed the rated capacity of the battery I have some idea where the line ought be drawn. I want to know, for example, that if I'm using these cells to power a motorized device that must start under load that the battery is capable to handling the startup current needed to get the motor moving. But I also want to know the de-rating I must put on the minimum-time-before-failure and charge/discharge cycle times. These are not part of the snippet of information provided. That poses a safety risk to the vaping community.
I'll assume some risk personally because I have the means and experience to test both my setups and the internal resistance of the batteries I use for experimentation to be sure they're not showing signs of excess wear. It is NOT likely that most sub-ohm vapers have that knowledge, much less the means at their disposal to do so. Heck most aren't disclosing the internal resistance of their mechanical mod and atty combination. This is value that must be known if you don't want to burn your hand on a hot switch or worse, fuse the switch closed! I'm certain no-one is talking about how long a VTC-4 should be in service under the stresses we place on them. There is a limit, and once breached we do NOT know what the failure mode will be in this application. We only speculate at this time and that poses a safety risk to the vaping community.
So there are a few of the reasons that justify concern over sub-ohm vaping.
Does that mean we shouldn't do it? No.
Does it mean we should evidence more than a cavalier regard for what we're doing? Definitely YES!
VAPE SAFE, VAPE ON!
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Disclosure:
My rig is a Stainless Steel Electric Angel clone with gold plated switch parts and a copper atty pin. The atomizers are both Patriot clones from Fasttech. Closed circuit resistance at the atty posts is 0.079 ohms (that's why my lowest build is 0.15 ohms! [That's 0.24ohms 4.2v 18.26A 76.7W]). My 18650 VTC-4's (I rotate two of them) have only been in service for approximately 30 minutes of vape time each. They have never been discharged below 3.7v. My 'daily' setup is two coils 10 wraps of #28ga Kanthal on a #50 (0.0700") drill bit (1.4 ohm per coil) wicked with cotton. The Patriot hood is drilled out with two #54 (0.0550") holes and I use AW 18650 1600mAh batteries for this configuration. The experimental Patriot hood is drilled out with 4 holes 5/32" (0.0781"). Sure there are better rigs out there but making a 3 liter vape cloud only needed this much!
I do have occasional access to a Fluke 8088A multimeter and a precision battery load center for battery/rig testing courtesy of my friends in the BioMed department of the hospital I work at. They have the setup and skill to test batteries because they have to make sure the ones we use in the machines to keep you alive won't fail

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