**Sub-Ohm Vaping** Discussion, Safety, Battery Info, & Warnings

[Artopsy]

a little more about heat
So kyle we learned something today.
I got a digital thermometer to try to read the temperature of coils in rebuildable and replaceable atomizers.
Why because I read this morning that Vegetable Glycerin decomposes to Acrolein at approximately 700 degrees F and I was wondering if the coils got that hot.
Well, the thermometer didn't work so well i couldn't read that small of a point.
But I noticed the coils we were testing were glowing at different colors from red up to almost white depending on the ohms of the coils, we also noticed the kanthal A1 oxidizing. So I did a search of temperature of kanthal by color.... nothing except for this
https://www1.elfa.se/data1/wwwroot/assets/datasheets/06080303.pdf

"The protective oxide layer on KANTHAL alloys formed at temperatures above 1000 deg C 1830 deg F consists mainly of alumina (AI2 O3) the color is light grey, while at lower temperatures (under 1000 C, 1830 F) the oxide becomes darker."
the picture shows four coils from left to right
#1 26 gauge unfired kanthal A1 coil .7 ohm ,
#2 28 gauge kanthal A1 coil is above 1 ohm normal firing.
#3 26 gauge kanthal A1 coilis a .7 ohm coil fired up to glow,
#4 26 gauge kanthal A1 coil is a .4 ohm coil fired up to glow

so from the pictures I would say coils #3 and #4 reached well into the 1400 F range double the safe temperature for Vegetable Glycerin! the .4 ohm coil did snap and the paper states that operational maximum for Kanthal wire below .4mm is 925c - 1050c, 1700F - 1920F meaning in all probability the coil reached a temperature of 1900 F

 

[pdib]

↑ this has nothing to do with the temperature that the coil reaches when a large part of the energy is going directly to phase change (liquid to steam). furthermore, the e-liquid gets as hot as the temperature required to turn into steam . . .. and then it turns into steam. A pot of boiling water maintains a constant temperature of ~212°F. Rather than get hotter, the water turns into steam, yes? . . . . .no?

 

[xpen]

(pure) VG has a boiling temp of around 290C, whatever that is in F, so your wet coil won't get beyond that - barring hotspots and hot legs. If you are worried about acrolein, just add some water to the VG (even 5% will do) and the boiling point will be lower.
On a side note, you would definitely notice acrolein in your vape, even tiny amounts of it..

 

[Mr.Mann]

(pure) VG has a boiling temp of around 290C, whatever that is in F, so your wet coil won't get beyond that - barring hotspots and hot legs. If you are worried about acrolein, just add some water to the VG (even 5% will do) and the boiling point will be lower.
On a side note, you would definitely notice acrolein in your vape, even tiny amounts of it..

What would we notice if acrolein is present? I imagine just a nasty taste, but specifically what kind of taste?

 

[xpen]

(Fortunately) I don't know about a specific taste, other than it's an acrid smell, but apparently it's irritant enough to make you cough up a lung - figuratively speaking
Have a look here: http://en.m.wikipedia.org/wiki/Acrolein

 

[Artopsy]

Vegetable Glycerin
Flash Point = 199C or 390F
Auto Ignition Temp = 370C or 698F
Boiling Point = 290C or 554F

I have felt Acrolein in the air around some heavy cloud producers, first sign to me was stinging in the my eyes, I also noticed that these particular cloud guys had very pink eyes. coincidence?

(pure) VG has a boiling temp of around 290C, whatever that is in F, so your wet coil won't get beyond that - ......

so what you are proposing is the coil reaches 1000 degrees dry but because it is surrounded by a substance it won't get hotter than that substances boiling point??
my experience is that the coil reaches X temperature due to the electron reactions in the wire and that the substance (in this case e-liquid) in contact with that heat source is exposed to that temperature. with enough quantity and time the cooling agent (e-liquid) will dissipate the heat, if the heat is not being regenerated by a reaction, as in a continual feed of electricity.
For instance if you drop a red hot iron rod on a block of ice, if the ice is thick enough the rod will melt its way into the ice being cooled by the ice until it is cooled to the point that it no longer melts the ice. Conversely if you take that rod and allow it to maintain its heat source (electrify it) it will melt through the block non stop.

the e-liquid gets as hot as the temperature required to turn into steam . . .. and then it turns into steam. A pot of boiling water maintains a constant temperature of ~212°F. Rather than get hotter, the water turns into steam, yes? . . . . .no?

No - water can and does get much hotter that 212F or 100C do you have a temperature gauge for you car? that reads the temp of the water flowing past the temperature sending unit. Most automobiles can run up to 120C or 248F before hitting the red zone and this is WITH a coolant added to keep the temperature of the water down. marine boilers operate with water at at 850 °F (454 °C) these are contained systems and so the water can not evaporate away. find a good thermometer and put it in the bottom of your boiling pot of water and see what it reads.

 

[Artopsy]

it's irritant enough to make you cough up a lung - figuratively speaking

but with time you can tolerate it. a cigarette was irritating enough for me to figuratively cough up a lung when I first started smoking but after a few weeks I could inhale that smoke DEEP with no immediate discomfort.

 

[xpen]

but with time you can tolerate it. a cigarette was irritating enough for me to figuratively cough up a lung when I first started smoking but after a few weeks I could inhale that smoke DEEP with no immediate discomfort.

Possible, unless you actually cough up a lung - or two - in the process of getting used to highly irritating substances..
I'm no MD, but my understanding of the problem is that you'd give up inhaling acrolein before getting used to it..

 

[Artopsy]

Thanks for the input it raised questions I needed to look into, I'm learning as we go and stumbled on the data of kanthal oxidizing the dry coils. which showed existence of temperatures about double of what i expected! We haven't started any wet testing yet.

 

[xpen]

Vegetable Glycerin
Flash Point = 199C or 390F
Auto Ignition Temp = 370C or 698F
Boiling Point = 290C or 554F
(...)

Sorry, not to be a jerk, but your point being.. ?

Anyway yes I think that in an open system the max temperature will match the boiling temp of the liquid involved.
Even empirically, coils don't get red hot as long as there's liquid to evaporate.. Ok the coil isn't truly submerged into the liquid, and what not, but you get the idea.. Peace, bro

 

[DaPopeLP]

Sorry, not to be a jerk, but your point being.. ?

Anyway yes I think that in an open system the max temperature will match the boiling temp of the liquid involved.
Even empirically, coils don't get red hot as long as there's liquid to evaporate.. Ok the coil isn't truly submerged into the liquid, and what not, but you get the idea.. Peace, bro

I think his point is VG's auto ignition temp is 698 degrees F with acro being made at 700.

 

[Artopsy]

point was somebody said VG turn to Acrolein at 370C and didn't know what that was in Fahrenheit which is 698F flash point and boiling point were just added to keep all the info complete.

 

[pdib]

↑ this has nothing to do with the temperature that the coil reaches when a large part of the energy is going directly to phase change (liquid to steam). furthermore, the e-liquid gets as hot as the temperature required to turn into steam . . .. and then it turns into steam. A pot of boiling water maintains a constant temperature of ~212°F. Rather than get hotter, the water turns into steam, yes? . . . . .no?

No - water can and does get much hotter that 212F or 100C do you have a temperature gauge for you car? that reads the temp of the water flowing past the temperature sending unit. Most automobiles can run up to 120C or 248F before hitting the red zone and this is WITH a coolant added to keep the temperature of the water down. marine boilers operate with water at at 850 °F (454 °C) these are contained systems and so the water can not evaporate away. find a good thermometer and put it in the bottom of your boiling pot of water and see what it reads.

ahhhhh, see? I thought for sure you were gonna go with "altitude" to contradict. Contained system . . .. cool.

 

[Artopsy]

ahhhhh, see? I thought for sure you were gonna go with "altitude" to contradict. Contained system

yes altitude does make a difference to but I think that is negligible. I also assume all the temperatures are at sea level.

 

[xpen]

point was somebody said VG turn to Acrolein at 370C and didn't know what that was in Fahrenheit which is 698F flash point and boiling point were just added to keep all the info complete.

If VG is going to spontaneously ignite at a temperature lower than that needed for producing acrolein, we'd be up in flames before having a chance to inhale any nasties.

I can see your point about coil temperatures, to be sure, but in practice it should stay around the boiling point temp of the eliquid - as long as the wick/coil ensemble is still wet.

I believe acrolein to be not much of a problem for vaping, other than the occasional dry hit you may experience once in a while (burning cotton - or better, cellulose - does release acrolein)

 

[Pedrobear]

Interesting read about the juice flash points and such. I have set a few *freshly* built .5'ers on fire somehow with the top off looking for hot legs, maybe this explains why it was happening for the most part.

On to the sub-ohming: I am pretty new to the vape world, however, spend alot of time reading and watching videos and such, which bring me to a question about subing.

How come, on a .7 twisted 28g kanthal coil at 23w ona VTC5/rDNA/Veritas RDA can I not really tell the difference between a 1.4 at 16w? (Other then my batt seems to be draining much faster/ going through more juice) Now, I also have a LP Reo mini w/ a LP 'mizer 2.0 I tried the same thing on, cept dropped it to .54 on a fresh AW 18490, other then it pretty much super heating the addy itself, it seems no different then 1.x? This phenomenon seem to occur on my ribbon/ 30/28/26 twisted/ single etc.., Maybe its just my RDA?

What am I doing wrong? Well maybe wrong is the wrong word, lol. I guess I just expected to notice some vape difference with all the variance in coil builds. I wick pretty much the same way always, as it seems to promote the best capillary action in my dripper to stop dry hits.

 

[edyle]

What would we notice if acrolein is present? I imagine just a nasty taste, but specifically what kind of taste?

The kind of taste that makes you go "ACK!!"

 

[edyle]

Vegetable Glycerin
Flash Point = 199C or 390F
Auto Ignition Temp = 370C or 698F
Boiling Point = 290C or 554F

I have felt Acrolein in the air around some heavy cloud producers, first sign to me was stinging in the my eyes, I also noticed that these particular cloud guys had very pink eyes. coincidence?


so what you are proposing is the coil reaches 1000 degrees dry but because it is surrounded by a substance it won't get hotter than that substances boiling point??
my experience is that the coil reaches X temperature due to the electron reactions in the wire and that the substance (in this case e-liquid) in contact with that heat source is exposed to that temperature. with enough quantity and time the cooling agent (e-liquid) will dissipate the heat, if the heat is not being regenerated by a reaction, as in a continual feed of electricity.
For instance if you drop a red hot iron rod on a block of ice, if the ice is thick enough the rod will melt its way into the ice being cooled by the ice until it is cooled to the point that it no longer melts the ice. Conversely if you take that rod and allow it to maintain its heat source (electrify it) it will melt through the block non stop.


No - water can and does get much hotter that 212F or 100C do you have a temperature gauge for you car? that reads the temp of the water flowing past the temperature sending unit. Most automobiles can run up to 120C or 248F before hitting the red zone and this is WITH a coolant added to keep the temperature of the water down. marine boilers operate with water at at 850 °F (454 °C) these are contained systems and so the water can not evaporate away. find a good thermometer and put it in the bottom of your boiling pot of water and see what it reads.

That is correct: as long as the coil is immersed or wet enough with liquid, it won't get higher than the temperature of the boiling liquid;
if you pump enough power to the coil, the coil will evoporate all the liquid faster than it can be rewicked, then you get a dry coil, and that is when the coil gets hotter and starts burning juice and producing acrolien or whatever bad stuff

 

[100%VG]

Popular 18xxx Battery Specs & Amp Limits: (Added 2/04/2014)

Hi,

Thanks for this thread!

I'm curious to know if there are any updated battery charts which list the batteries that have come out since this chart was made (probably some time in 2013). And maybe even some charts that include 26xxx series now.

It would also be nice to know which of those batteries actually meet their labeled mAh and Amp ratings, whether the Amp markings on the battery are Continuous or Pulse, and which of the batteries are genuine and which are rewraps or even fakes. But most importantly, which ones are the best, whether considering them for Sub-Ohm Vaping or a VV/VW Mod. The Sony VTC5 has fakes out that are rewraps. Most Efest batteries are rewraps, if not all of them, but if there is a high quality battery under the Efest wrapper, and the markings are correct, then I guess that's OK. I'm just sick of all the deception!

I recently got two Efest Purple 18650 IMR 20A 3100 mAh Flat Tops, only to find that they didn't work any better or last any longer in my Mech and Dripper with a 0.75Ω dual coil than my 1.5+ year old Panasonic CGR18650CH's. A little research showed that they are rewrapped Panasonic 10A batteries. Maybe I got fakes, but I got them from an e-cig vendor in Florida (I don't get batteries from eBay!). Or maybe I was fooled by all the hype about the Purple label, but I was very disappointed. I'm using them in my ZMax now, because their 3100 mAh rating lasts longer in there, plus they are new.

Anyway, if there are new charts to be posted, I'd certainly appreciate knowing about it/them.

Thanks again.

 

[Ezah]

To see the test of batteries at 0,5 ohm load I invite to my blog: vape-safe. It is still under construction but most of batteries topics is already published.