New studies find carcinogens in vg and pg at high temps, even in tootle puffers

[sofarsogood]

But that doesnt prove anything to me in terms of "what is real life conditions while vaping" which is my goal here. I am satisfied that the TC of the board is accurate +/- 10 degrees.

A test with dry cotton in TC mode may reveal the cooling effect of liquid in the cotton, suppose it lowers the temp of the sensor 15 F. Then when you do tests with kanthal in watts mode you'll havea better estimate of coil temp by adjusting for the temp difference between wet and dry cotton you found in TC mode. It seems like the concern is, what is the wiire temp of kanthal in power mode. Seems like you are getting closer to a technique for measuring that accurately.

 

[mikepetro]

That's a little warmer than I would have expected from 15W.

Which is a very good point, depending on the coil, airflow, etc, it doesnt take much wattage to get high temps.

 

[Eskie]

Which is a very good point, depending on the coil, airflow, etc, it doesnt take much wattage to get high temps.

Which pretty much validates the title of the thread.

 

[mikepetro]

Placed sensor under far right coil, it was significantly cooler (about 290) at the same 400 degree setting.

I suspected it would be though, the wick is always more scorched in the middle than on the outside.

 

[beckdg]

Interested to see results from a coil after a month of daily use.

Tapatyped

 

[awsum140]

Again, kudos, Mike! You're going well above and beyond. You are wearing glasses and a bow tie while doing these tests to validate the results, right?

OK, now I'm cornfuzzed. The wire should be a linear representation of the alloy. The resistance should be linear across the full length of the coil wire. The coil temperature is determined by the resistance of the wire at a given temperature. So what this would seem to indicate is that the coil resistance is not linear due to the effect of the multiple wraps concentrating heat on the center wraps causing a non-linear effect on the resistance of the wire.

I will say, from the photo, that last wrap where the thermocouple is doesn't look as tight to the wick as the rest of the wraps.

 

[mikepetro]

Interested to see results from a coil after a month of daily use.

Tapatyped

LOL, I dont think that will happen. This thermocouple wire is very delicate, I would end up breaking it long before the month elapsed.

Now, I did ask Brandon about this (yes, I know, he has a vested interest) and he did tell me that, at a given temperature, "nasties" significantly increased with dirty wicks.

 

[mikepetro]

Again, kudos, Mike! You're going well above and beyond. You are wearing glasses and a bow tie while doing these tests to validate the results, right?

OK, now I'm cornfuzzed. The wire should be a linear representation of the alloy. The resistance should be linear across the full length of the coil wire. The coil temperature is determined by the resistance of the wire at a given temperature. So what this would seem to indicate is that the coil resistance is not linear due to the effect of the multiple wraps concentrating heat on the center wraps causing a non-linear effect on the resistance of the wire.

I will say, from the photo, that last wrap where the thermocouple is doesn't look as tight to the wick as the rest of the wraps.

I think you are dead nuts on the money about the length of the coil being a non-linear resistance. TC boards measure the total resistance of the wire, i.e. the entire length. If there were different resistances in sections of the wire a TC board would not know it.

I have always seen higher discoloration in the center of the wick versus the outer edges. I "suspect" that the effects of air/juice flow come into play. I also suspect that loops in the middle of a coil get hotter because they have a hot loop on either side of them, where at the edge you have a hot loop on only one side.

 

[beckdg]

LOL, I dont think that will happen. This thermocouple wire is very delicate, I would end up breaking it long before the month elapsed.

Now, I did ask Brandon about this (yes, I know, he has a vested interest) and he did tell me that, at a given temperature, "nasties" significantly increased with dirty wicks.

I meant use it as normal.

Clean and replace wicks as necessary.

Clean coil, insert fresh wick, THEN test.

Curious how degradation from normal use affects TC accuracy.

I assume different metals in a compound would degrade differently possibly changing the compound and affecting the reading, thus the control too.

Tapatyped

 

[mikepetro]

OK, so I stuck the sensor into the middle of the wick, pushed in so the tip of the sensor is inserted to the middle of the coil lengthwise.

So this is the temp the juice sees in the middle of the wick:

• Normal 3 sec puffs
• Same 400 degree TC setting
  
• 1st puff the center of the wick only got up to 252 degrees.
• Successive puffs kept the wick temp rising
  
• Also, if you increase the puff length, the center of the wick continues to rise.

So,

• It would appear that juice inside the wick does not get heated as hot as the coil.
• With single hits the wick stays pretty cool, but with chain hits the wick approaches the coil temp. TC only limits the coil temp, but the wick temp is not being controlled.

 

[Lessifer]

Which pretty much validates the title of the thread.

Not quite, it validates coil temps getting that high, even in tootle puffer gear, not necessarily the creation of carcinogens. Though we do know they can be created, it's the specifics of how and when that are the real concern, to me.

OK, so I stuck the sensor into the middle of the wick, pushed in so the tip of the sensor is inserted to the middle of the coil lengthwise.

View attachment 650935

View attachment 650939

So this is the temp the juice sees in the middle of the wick:

• Normal 3 sec puffs
• Same 400 degree TC setting
  
• 1st puff the center of the wick only got up to 252 degrees.
• Successive puffs kept the wick temp rising
  
• Also, if you increase the puff length, the center of the wick continues to rise.

So,

• It would appear that juice inside the wick does not get heated as hot as the coil.
• With single hits the wick stays pretty cool, but with chain hits the wick approaches the coil temp. TC only limits the coil temp, but the wick temp is not being controlled.

View attachment 650933

If you do this same test in non-tc mode is there a point where the temp maxes out on its own, if the wick is kept saturated? Are you providing any airflow?

 

[mikepetro]

Ok, so all of my tests were done with the juice control wide open to ensure good wick saturation


At 15watts with juice flow wide open:

At 15watts with juice flow closed down (note, not a dry, or even bad tasting hit):

At 20 watts with juice control throttled back:
The 2nd and 3rd hits tasted slightly burnt to me, not dry hits. So I would say that yes, I taste "something" when you get over 500 degrees.

Not going to push the wattage up anymore as the insulation of the sensor cant handle any hotter.

 

[mikepetro]

If you do this same test in non-tc mode is there a point where the temp maxes out on its own, if the wick is kept saturated? Are you providing any airflow?

I didnt do a screen capture of it but at 15w the wick center maxed out at about 400 degrees after several chains vapes. The temp was still increasing slightly with each chain hit, but the ROR (rate of rise) with each hit had almost leveled out. I quit after about 6 hits.

Edited to add:
Yes, I have the airflow and juiceflow wide open for every test unless explicitly stated. I then vaped the tank normally (for me which is a strong MTL style).

 

[Lessifer]

I didnt do a screen capture of it but at 15w the wick center maxed out at about 400 degrees after several chains vapes. The temp was still increasing slightly with each chain hit, but the ROR (rate of rise) with each hit had almost leveled out. I quit after about 6 hits.

What's the pg/vg ratio of the liquid you're using?

 

[mikepetro]

What's the pg/vg ratio of the liquid you're using?

The liquid is a 36mg 50/50 mix with no flavor. It is DIY, and I am confident in my mixing skills.

 

[Lessifer]

The liquid is a 36mg 50/50 mix with no flavor. It is DIY, and I am confident in my mixing skills.

Wasn't questioning your mixing skills, was going to suggest trying different pg/vg ratios to see if it has an effect on that temp leveling that you saw. Higher pg might bring the temp down from 400, higher vg might raise it.

 

[mikepetro]

So, some conclusions:

• Coil temps do coincide with DNA board readings.
• Chain vaping in wattage mode clearly increased temp with each hit
• Longer hits in wattage mode clearly increased temp
  
• Less air or juice flow clearly increased temp in wattage mode
  
• I personally didnt taste anything "bad" until over 500 degrees, but it was detectable above that point
  
• Under normal vaping (not chain), the center of the wick was considerably cooler than the coil
• Depending on the coil/juice/air it doesnt take much wattage to get over 400 degrees, and I didnt taste anything bad until you hit 500.

Now, if you couple that with the studies in the OP, where pg/vg were measured at specific temperatures, it does lead to the premise of staying under 410 degrees for maximum safety, especially if you have a high vg mix.

Specifically, I could not "taste" the area highlighted in yellow below.

 

[mikepetro]

Wasn't questioning your mixing skills, was going to suggest trying different pg/vg ratios to see if it has an effect on that temp leveling that you saw. Higher pg might bring the temp down from 400, higher vg might raise it.

I will try some straight vg and straight PG and see what happens.

 

[Eskie]

So a 400-450F range should be within a "window of safety" based on the data presented with the above reactor temperature study. Now to see if the reactor and a modern generation tank behave the same.

Mike, you've gone above and beyond with this. And no, I'm not suggesting you do the chemical analysis too, unless you have access for that testing as well. And if you do, I'd love to know where you work because it sounds like someplace I'd love to submit my resume.

 

[Plettschner]

So this is the temp the juice sees in the middle of the wick:

• Normal 3 sec puffs
• Same 400 degree TC setting
  
• 1st puff the center of the wick only got up to 252 degrees.
• Successive puffs kept the wick temp rising
  
• Also, if you increase the puff length, the center of the wick continues to rise.

So,

• It would appear that juice inside the wick does not get heated as hot as the coil.
• With single hits the wick stays pretty cool, but with chain hits the wick approaches the coil temp. TC only limits the coil temp, but the wick temp is not being controlled.

Wow. Awesome info you've gathered and shared.

What did you mean by this, besides the obvious:

TC only limits the coil temp, but the wick temp is not being controlled.

The coil temp is being controlled and the wick is being heated by the coil and has no way to exceed the coil temp, so indirectly, the wick is temp controlled, no?


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