Charring vs combustion

SpaceCoyote

Well-Known Member
Nope, you are not correct on that. Combustion is a chemical chain reaction described by the fire triangle. You will have little to no doubt when combustion occurs. It is so drastic you usually do not have to peek at the herb to find out because you will have a burning reaction and smoke with a life of its own (you just started a fire). In a vape bowl you will usually find a burning ember.

Black is evidence charing happened but not combustion.

This matches my experience. At first, when I'd get a really thick cloud, or my herb looked really dark, I'd think "oh dear, I combusted!" But then later I'd REALLY combust and the difference is night and day!
 
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salivape

Well-Known Member
Besides agreeing on the exact term, I think that some people here are worried that incomplete combustion is a sign that pyrolisis happened (ie heat broke chemical compounds appart, possibly creating new byproducts in the process, said byproducts are often "free radicals" and they try to combine with everything they touch because they shouldn't exist in this state... and most often they are carcinogens)

So while it might not be a real combustion, I still think we want to avoid charring for health safety reasons.

Yep, that's what I was getting at I just didn't articulate it as well as you, so thanks for clarifying.

Anyway, I'd love to contribute further but this thread is starting to go way over my head. I'll be here in spirit. I may be back for a little convo if it dumbs down a bit :freak:
 

Tweak

T\/\/34|<
Found this pretty good source:

"Fire investigators talk about the fire triangle: heat, fuel and an oxidizing agent (most commonly oxygen). In truth, the fire triangle should really be a square as there is a fourth requirement for the fuel and oxidizer to interact in a self-sustaining reaction in order to achieve a fire. This fourth component is the key to understanding the difference between smoldering and flaming combustion.

Flaming combustion involves gaseous fuel mixing with air, reacting with oxygen and releasing heat. The combustion process produces a variety of gases (CO2, CO, H2O etc.) as well as particulate matter known generally as smoke. Regardless of whether the fuel was originally a liquid or solid, the overall burning process must gasify the fuel. With liquids, the supply of gaseous fuel is a result of evaporation at the surface from the heat generated by the flames. Solids entail a significantly more complex process involving chemical decomposition (pyrolysis) of large polymeric molecules. Certain combustible solids such as sodium, potassium, phosphorus, and magnesium can be oxidized directly by oxygen in the air without the need of pyrolysis.

Smoldering combustion is a condition where all four elements of a fire are present, but are imbalanced. Smoldering combustion exists in conditions where there is a self-sustaining reaction, but the reaction is limited by some of the constituents of the fire “square”. A smoldering fire will not easily change to flaming combustion. To understand why, one must understand how smoldering works.

Smoldering is defined as a “self-sustaining reaction in which the heat released by surface oxidation causes pyrolysis of the unaffected fuel adjacent to the reaction zone, which in turn yields a rigid char which will subsequently undergo surface oxidation”. Beyond the technical jargon, the heat, oxygen or fuel must be sufficient to maintain a continuous reaction but not enough for the fire to grow uncontrolled. Typically, smoldering combustion has reduced temperatures, limited ventilation and/or an environment where the generated heat can be partially dissipated. In order to convert smoldering combustion into flaming combustion, one of these three items must be altered. A typical example of smoldering combustion is a cigarette. A cigarette will not convert into flaming combustion unless one of the three fire triangle components is altered. Either more oxygen must be added, the temperature has to be raised or the heat produced by the cigarette must not be dissipated. An example of the latter is when a cigarette is dropped into the back of a sofa. This confined space reduces the dissipation of the heat from the cigarette and allows the smoldering cigarette to convert into flaming combustion. The same principle applies to all smoldering combustion. In smoldering combustion, the rate at which gases are produced are insufficient to sustain a flame.

Several types of materials are prone to smoldering including wood; most wood-based products; cellulose; viscose rayon; dusts and fibers from vegetable matter; rubber latex foam; some leathers; certain polyurethane foams and some phenol-formaldehyde foams.

By understanding the conditions that permit smoldering combustion to convert to flaming combustion, the fire investigator can assess whether “where there’s smoke-there’s fire” holds true."

So is it self-sustaining or does the vaporizer provide the heat?
 

PAZ

Well-Known Member
All these terms are pretty simple if you think of it in terms of a campfire.

Everyone has had those times where you couldn't find proper fuel (say a small amount of newspaper), so as the newspaper burned, the wood would get charred on the outside but there would be no flame, so no combustion would occur. This is most likely due there not be a sufficient amount of heat, which will cause incomplete combustion.

Smouldering is when you let a campfire die out on its own. There's no fire left, but the ash and some charcoal still retain a large amount of heat. So the fire gave the material the heat, but it has such a high heat capacity that it will retain the heat and slowly burn. If you add more fuel (logs/small sticks) and blow on the bottom of the bit, it will give the fire oxygen.

And combustion, well that's the obvious one when you have a nice campfire going during those nights.

So putting these in terms of a vaporizer, charring will still release free radicals from the cellulosic material, but only a small amount as it's such a small surface area and doesn't completely combust.

Smouldering I don't really see how that would happen in a vaporizer, the temperature would have to be hot enough to cause combustion for it to occur. Maybe smouldering would occur right before combustion, but I can't see it happening without the conditions being proper for combustion as well.
 

olivianewtonjohn

Well-Known Member
Do I have this right?

— Charring is incomplete combustion due to a lack of oxygen
— Smouldering is burning slowly which is flameless combustion

I like these terms because they help to discuss where heat, fuel, and oxygen are in relation to when combustion happens.

I think charring really is an end point. The process doesnt really matter:

"By the action of heat, charring removes hydrogen and oxygen from the solid, so that the remaining char is composed primarily of carbon."

"Normal combustion consumes the char as well as the gases produced in its creation, while industrial processes seek to recover the purified char with minimal loss to combustion. This is accomplished by either burning the parent fuel (wood or coal) in a low-oxygen environment or by heating it to a high temperature without allowing combustion to occur."

http://en.wikipedia.org/wiki/Charring

I am sorry if anyone misunderstood, I wasnt saying that vaporization is the same as smouldering. I was saying that charring-incomplete combustion could be the beginning steps of smouldering. Seeing as how one of the examples of smouldering is burning a cigarette I guess I was right to an extent, but really not related to our discussion.

So putting these in terms of a vaporizer, charring will still release free radicals from the cellulosic material, but only a small amount as it's such a small surface area and doesn't completely combust.

For me the question was that since combustion is occurring, why doesnt it become "complete" combustion? It is an exothermic reaction, once started what's stopping it?

Have you ever overheated a Vapman? :cool:

Any heated container, cylinder, or bowl (oven) can cause smoldering which is simply combustion without enough oxygen for flames. Smouldering is self-sustaining combustion as it slowly consumes the fuel and at lower temperatures than flames, all the elements for combustion are happening just not enough oxygen to produce flames.

My guess is smouldering is experienced more frequently by vapers than full flaming combustion because of the lower temperatures most vapes run at — to vaporize instead of combust, but damn close never-the-less (this is why it happens). Also the herb ovens are often small and not exposed to air so there is not much oxygen unless through the action of drawing or something. Have you noticed combustion will always bite you on a draw?

I dont believe it is smouldering because you have to continue to apply heat to get anything out of it. If you light a cigarette it wont go out unless it runs out of fuel or oxygen. In the case of combusting a cigarette, yes oxygen is reduced which causes the smouldering but it provides its own heat.
 

olivianewtonjohn

Well-Known Member
No more heat required for smouldering. Once smouldering combustion begins you can remove the heat source that caused it and smouldering (and smoking) with continue until the chain reaction stops which means one of the legs of the fire triangle (or square) have been removed/consumed.

If you have ever opened a vape after an event of combustion and saw a glowing red ember with no flames, in fact I never have seen flames coming from one of my vapes after combustion. I have had self-sustaining smouldering occur many times.
Oh I see what you were saying; on accident smoldering can occur. Totally makes sense to me, especially given the source Tweak posted; using cigarettes as an example of smouldering. So what we generally refer to as combustion on this site is really a specific type of combustion, smouldering
 

hoptimum

Well-Known Member
My guess is smouldering is experienced more frequently by vapers than full flaming combustion because of the lower temperatures most vapes run at — to vaporize instead of combust, but damn close never-the-less (this is why it happens). Also the herb ovens are often small and not exposed to air so there is not much oxygen unless through the action of drawing or something. Have you noticed combustion will always bite you on a draw?

This is absolutely true, and I experienced it tonight using my lsv with an eq screen in a m2m adapter. As usual I set the dial full to pre heat, loaded the small bowl, and dialed back to 1 oclock. But I didnt give the rod enough time to cool down and I started to notice the bite as you call it as I drew through the bubbler, followed by the acrid scent of burning. Pulling off the lsv I noticed mostly charred herb, but not smoldering or ash. I had taken it right to the brink, but I would not call it combustion.
 
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Reliable ShotZ

Active Member
My vp100 would combust and wouldn't even have black material, the tingle in my lungs was a big giveaway and the taste.
 
Reliable ShotZ,

Derrrpp

For the world is hollow and I have touched the sky
My vp100 would combust and wouldn't even have black material, the tingle in my lungs was a big giveaway and the taste.

I'm not sure how I can see combustion taking place and not leaving black charring and/or ash... Are you sure it actually was combustion? I could be wrong though, I've been wrong before lol ;)
 
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Dan Morrison

Well-Known Member
Manufacturer
Loving this thread so far!

It may help to simplify further discussion if we can all agree on the specific meanings of these terms that we, up until reading this thread, may have wildly differing descriptions for.

Smouldering is evidenced by a self sustaining reaction involving the production of heat and light. A glowing ember, no matter how small or hidden, is the most obvious sign of smouldering. This term can also be considered a form of incomplete combustion.

Combustion is somewhat of an umbrella term, but I think that for our purposes it should govern a process that can be sustained after the application of heat from the vaporizer is stopped. For example, if a chamber load is said to have combusted, it should be understood that an ember was created, as the ember is a good indicator for that chain reaction that can sustain smouldering.

Also, we should only be concerned with smouldering, since we are not producing a flame. A flame would actually be evidence of a more efficient form of cumbustion, resulting in less harmful emissions since much of the escaping volatiles are being converted into heat energy. Though, if you had a flaming bowl of cannabis, the flames would also consume a lot of the actives that we want to inhale, so it would be a much less efficient extraction.

Now, to bring this all home to roost, I think the question we are all trying to answer is, how close can we get to the edge of smouldering? Do the benefits of complete extraction at high temperatures outweigh the possible health effects of charring?

Charring in a vaporizer blurs the line between combustion and non-combustion. It is, rather, evidence for almost acheiving a self-sustaining reaction and an ember. Even though smouldering is not reached, the char should be seen as evidence of improper heating of the material for those who are seeking the most efficient extraction and least harmful vapour.
 
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RUDE BOY

Space is the Place
char should be seen as evidence of improper heating of the material for those who are seeking the most efficient extraction and least harmful vapour.

But Charring IS the most efficient (and only) means for me to obtain relief from neuropathic pain.
(other than smoking)
If I had only stuck to those temps everyone seemed so set on for vapes a couple years ago ( the idea that 374F is optimum for vaporizing) I'd still be smoking bowls.
 

Dan Morrison

Well-Known Member
Manufacturer
Very good point @RUDE BOY , Everyone has to determine what their individual needs are. Its a question of balance. You obviously have to weigh the positive effects of high temperature vaporization vs. the negative byproducts of charring (which I think are very minimal). For you, its a no brainer!

Personally I also like vaporizing to very dark brown or black, I feel as though the extraction is more complete, the effects more desireable, and the negatives always outweighed.

Technically, however, I recognize that lower temperature extraction produces vapour that is less likely to contain harmful byproducts. But... you could go so far as to say that an even MORE healthy vapour is produced at room temperature, in the form of scent molecules. Obviously everyone has to draw their own lines.

In the end, as long as we are not combusting in the traditional sense, we are going a long way to making the ritual of cannabis consumption more healthful.
 

Reliable ShotZ

Active Member
Maybe combustion was the wrong word to use but I was definitely getting smoke from it. It was very obvious since my lungs weren't recovering from being an ex smoker but now I have a true vaporizer they are.
 
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hoptimum

Well-Known Member
But Charring IS the most efficient (and only) means for me to obtain relief from neuropathic pain.
(other than smoking)
If I had only stuck to those temps everyone seemed so set on for vapes a couple years ago ( the idea that 374F is optimum for vaporizing) I'd still be smoking bowls.

Luckily plenty of vaporizers can achieve enough heat to char or even combust herb if you push them hard enough. Being able to precisely control temps is the main reason I vape.
 

Prof77

Well-Known Member
Blacktop Update: I am now using the clear sleeve on my Air and getting more "charring" on top of stem but less than when using black sleeve. I will attempt to do a side by side video using same stem and same herb with the Solo and the Air on the same temps.

I also notice on green setting I cough a lot and never ever coughed on the Solo even on the highest temp setting.

Thanks all for the amazing replies - great thread!

P77
 

max

Out to lunch
Last night I was finishing off a bowl in the EVO. Had it set to 3 o'clock. I've used this setting many times in the past without combustion (never combusted in a VapeXhale product period before), but for whatever reason (hopefully not a runaway temp problem with the unit) this time I got a glass (and a lung) full of smoke. It's been years since I accidentally combusted with a vape, and my throat and lungs were very unhappy. As soon as I got through choking and coughing I cleaned everything and emptied the ELB. I didn't inspect the bowl remains closely for ash, but it was mostly black, charred material. It made me rethink the 'combustion = lots of ash' attitude I'd had, but reinforced my conviction that if you're using a waterpipe and combust, there's no mistaking all that smoke for vapor. That much smoke makes me feel like a fire eater who forgot to coat his throat.
Combustion is somewhat of an umbrella term, but I think that for our purposes it should govern a process that can be sustained after the application of heat from the vaporizer is stopped. For example, if a chamber load is said to have combusted, it should be understood that an ember was created, as the ember is a good indicator for that chain reaction that can sustain smouldering.
Whatever floats your boat, but IMO, in the vaping world, combustion means you're getting smoke instead of vapor, and for me, smoke is so much more harsh than vapor, there's no question about it. Even though it's been years since the last time I combusted with a vape, I vividly remember the shock to my system when it happened.
 

DopeShow

Member
No trolling. Please do not post any content that disrupts the peace and harmony of this board. Don’t post for or the purpose of starting a dispute.
Loving this thread so far!

It may help to simplify further discussion if we can all agree on the specific meanings of these terms that we, up until reading this thread, may have wildly differing descriptions for.

Smouldering is evidenced by a self sustaining reaction involving the production of heat and light. A glowing ember, no matter how small or hidden, is the most obvious sign of smouldering. This term can also be considered a form of incomplete combustion.

Combustion is somewhat of an umbrella term, but I think that for our purposes it should govern a process that can be sustained after the application of heat from the vaporizer is stopped. For example, if a chamber load is said to have combusted, it should be understood that an ember was created, as the ember is a good indicator for that chain reaction that can sustain smouldering.

Also, we should only be concerned with smouldering, since we are not producing a flame. A flame would actually be evidence of a more efficient form of cumbustion, resulting in less harmful emissions since much of the escaping volatiles are being converted into heat energy. Though, if you had a flaming bowl of cannabis, the flames would also consume a lot of the actives that we want to inhale, so it would be a much less efficient extraction.

Now, to bring this all home to roost, I think the question we are all trying to answer is, how close can we get to the edge of smouldering? Do the benefits of complete extraction at high temperatures outweigh the possible health effects of charring?

Charring in a vaporizer blurs the line between combustion and non-combustion. It is, rather, evidence for almost acheiving a self-sustaining reaction and an ember. Even though smouldering is not reached, the char should be seen as evidence of improper heating of the material for those who are seeking the most efficient extraction and least harmful vapour.

U seem to be the only one here who understands the difference between smouldering/charring and complete combustion. And indeed slight combustion is occurring in cannabis at temps >200 C. Achieving the Boiling Point temps of the active ingredients while regulating smouldering is key to the proper function of any vaporizer. The staff here do not seem to understand this basic principle and are guilty of spreading their ignorant view on this matter to the members of this site.

Maybe they should rename the site WEDONTGIVEAFUCKABOUTCOMBUSTION. COM
 
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DopeShow,

dorkus_molorkus

Well-Known Member
The staff here do not seem to understand this basic principle and are guilty of spreading their ignorant view on this matter to the members of this site.

Maybe they should rename the site WEDONTGIVEAFUCKABOUTCOMBUSTION. COM


there are plenty of things that many peeps are guilty of.

Some of those are here for all to see .
God knows some of the staff here are challenging at times as well.
(Ive been trying to get @Stu sacked for years for his shitty attitude & his penchant for trannies & courgettes)

But basic principles & who is ignorant of what, on which particular views and who understands them is open to interpretation.

Perhaps we should rename this site WEDONTGIVEAFUCKABOUTTHOSEWHODONTGIVEAFUCKABOUTCOMBUSTION.COM?

char it, burn it, vape it, stick it up yr ass or choke on it.
we dont care,

but dont rag on the staff cause they dont see the world yr way.

you have to start yr own site for that sort of self indulgent crap.

like I did at www.eatmydick.com

you have a nice day.:wave:
 
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DopeShow

Member
God knows some of the staff here are challenging at times as well.

But basic principles & who is ignorant of what, on which particular views and who understands them is open to interpretation.


you have a nice day.:wave:

I disagree basic principles of physics are not open to interpretation.

They seem to be confused about the distinction between binary combustion as the type caused by open flame ignition and the incomplete combustion (smouldering /charring) thermodynamics of convection heating which can occur at levels above >200C.

A basic level of physics would help u and the staff here to understand this.
 
DopeShow,

dorkus_molorkus

Well-Known Member
oh dear,
and those same physics and reply editing skills got you heaps of pussy when you was in college right? (or junior high, college kids tend to be more respectful):rofl:

yup, binary combustion vs open flame ignition & (the other rubbish), thermo-dynamics of convection heating ensures you have the moral high ground here and therefore obliged to point out the guilt & ignorance we are all complicit of?

or just me & the staff?

or just the staff?

rofl- you are fun.............
 
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