Activated Carbon Information

[John Eberhart]

redsquirrel

I put this on a different post but thought it should also be in the scent control section.

I'll be happy to start a match on the topic of activated carbon lined suits and their effectiveness. I hunted for 36 years without using a Scent Lok suit and 14 years with it and for any hunter to argue its effectiveness is not only a waste of their time, it shows they have done no research on the technology of activated carbon. Whenever there is a new scent adsorption, eliminating, or cover up technology brought into the hunting market, take my word for it, it was not developed by the hunting manufacturer that brought it to market.

The average R & D cost to a pharmaceutical company to bring a single FDA approved drug to market is around 2 billion dollars and most hunting companies are in the 5 to 70 million dollar a year annual gross bracket and simply can't afford scientists and or a sophisticated R & D department.

Any technology that actually works (and many in the hunting industry don't) for molecular adsorption, killing bacteria, molecular containment in the form of blocking, or an anti-microbial, was researched and developed for a much larger and far more sophisticated worldwide market industry than our little hunting industry. The hunting industry simply piggybacks on the technologies that were developed by other industries and governments worldwide.

Personally I never believe any advertisements from any manufacturers, any of the bloviating endorsements spewed by the so-called hunting experts that get paid to endorse them, or anything on any manufactures website, including Scent Lok's, when it comes to hi-tech scientific technology. Manufacturers and hunting personalities can and do lie and their is no hunting advertising police that hands out tickets for lying or false advertising.

This is where a little research by the hunter questioning any technology should come into play. All anyone has to do is simply Google the technology to see if it actually exists and if it does; how many other worldwide industries, hospitals, restaurants, governments, etc. use it, how it is used, and what does it do, and how effective is it when compared to similar technologies used for the same purposes.

Google activated carbon and you will find it is the most adsorbent substance know to man.

Scent Lok was sued for false advertising by a few Minnesota hunters that got winded and while extremely expensive to defend, it ended up being a blessing in disguise for any hunters willing to take off their blinders and look at what the outcome was. For a United States District Court, an independent lab at Rutgers University proved beyond a preponderance of a doubt that Scent Lok’s clothing worked as advertised.

The following paragraph was taken directly from Court’s final ruling.
-Expert scientific testing found that, using highly elevated odor concentrations that were “likely ten thousand fold greater than a human body could produce in the course of 24 hours”, Scent Lok carbon lined clothing blocked or adsorbed 96 to 99 plus percent of odor compounds, and essentially 100% of surrogate body odor compounds.

Activated carbon is used in literally thousands of industries worldwide for filtration, purification, storage, and molecular adsorption applications and when Googled here are a few of the hundreds of uses for it:

Gas purification, decaffeination, gold purification, metal extraction, drinking water purification, refrigerant gas adsorption, sewage treatment, every countries chemical warfare suits, by NASA in primary life support systems better known as space suits, gas masks, water softeners, paint respirators, filters in compressed air, volatile organic compound capture, dry cleaning processes, automobile filtration systems, gasoline dispensing operations, groundwater remediation, to adsorb radon for testing air quality, for oral ingestion in hospitals worldwide to treat overdose patients, in intensive care units to filter harmful drugs from the bloodstream of poisoned patients, to adsorb mercury emissions from coal power stations and medical incinerators, to filter vodka and whiskey of organic impurities, and by the US Dept. of Energy to store natural and hydrogen gas.

Just as; NASA, auto industry, U. S. Dept. of Energy, hospitals, and every Dept. of Defense in the world didn’t pull activated carbon out of a hat and say, hey let’s use this stuff, neither did Scent Lok.

Microscopic evaluations show that if all the surface areas of the primary, secondary, tertiary pores, and exterior surface of each particle of activated carbon were flattened and laid on a flat surface:
-A tablespoon of activated coconut carbon particles (activated carbon Scent Lok uses) has a surface area of just over 3 ½ football fields.
-And one pound of activated carbon particles (a small butter tub) has a surface area equal to that of approximately 100 acres (more than a half mile in length and a quarter mile in width).

Here's the kicker and the main reason many hunters say Scent Lok's activated carbon lined suits don't work. A suit is not magic and the many hunters that owned them and got winded, had no clue how to properly care for them and what to do in conjunction with them to have a total scent free regiment.

Carbon lined clothing requires very specific care and absolutely must be used in conjunction with a carbon lined headcover with drop down facemask, carbon gloves, knee high rubber or neoprene boots, and a frequently washed fanny or backpack.

Some ifs: If you; exclusively use scent eliminating sprays, wear face paint to look cool like the TV and video so-called experts do, wear a favorite logo ball cap like the TV and video guys do, don’t regularly wash your pack in scent free detergent and store it in an air tight container, don’t wear clean rubber or neoprene knee high boots, or if you wear regular gloves when ascending trees, you should definitely “hunt the wind” because your scent regiment is not perfect and perfect is a must when hunting mature whitetails.

Of course there will always be that guy that says, hey I killed a lot of deer without a scent free regiment. Cavemen also killed dinosaurs with spears and Indians killed with stick bows and wooden arrows. I also killed well over 100 deer with my bow before activated carbon technology was introduced into the hunting marketplace, but I have always been willing to check out anything new and take full advantage of it if it works and I feel totally naked in the woods with a properly cared for Scent Lok suit.

My willingness to look at every new hunting item is also what led me to use an Anderson Treesling in 1981. At first I hated it because it was different and uncomfortable, but I saw the huge advantages it would bring me if I altered it for my personal use. I have been using a harness system ever since and think conventional stands of any type are archaic and outdated.

If anyone would like me to forward them a guide in how to properly care for activated carbon lined clothing, go to my website at: www.deer-john.net and e-mail me your request.

 

[redsquirrel]

Re: Washing Machine Options

John, thanks for that great post. I'm away for the weekend and on my phone but when I get home I'm going to make this a sticky. I'm 100% on board with using scentlok and your system. Since I read your first book 6 years ago I have been using it and not only do I agree with the science behind it but I have seen it work in the field.

 

[joaxe]

John,

Great post!

However, I'll be honest...I don't use activated carbon clothing for the simple reason that I'm just too damn lazy to take care of it properly (besides, before the ruling and prices went down a bit, it was just too expensive for me). :lol:

...maybe it's time to rethink. :idea:

I use a different technique that has a lot of followers...smoke! I simply smoke my hunting clothes and gear with hickory smoke and one of those bee smokers. I never thought it would work as well as it does for me. I've been less than 10 yards away from mature animals over the past few seasons using it and have harvested quite a few while "smoked up". :lol:

Whatever is used...it's always great to see more deer than the other guys and get up real nice and close to 'em!

"Aero" Joe

 

[Saddle Assassin]

I have smoked up a swell and it does se to work but I am going all wind for this year.

 

[Sniper4hire]

As much as I respect John, and believe me when I tell you John Eberhart has influenced my hunting technique (and success) more than anyone ever, I have a strong dislike for all types of scent control garments, sprays, or anything pretty much with the possible exception of Buck and Doe Tarsel Gland and fresh deer urine. I feel most of them are gimmicks, and the ones that actually work, work with nominal results.

I truly believe carbon activated suits are oversold as far as ability is concerned. But my primary issue is simply that it is impossible to eliminate human scent completely. So with that said, if a hunter was to eliminate 90% of his or her scent on a given hunt, would a deer, any deer, not be able to smell you if it was to pass down wind.

A few years ago, I was so obsessed with scent control that it literally ruined the joy of the hunt. I was doing it all, keeping clothes outside, isolated from camp smells, washing them in pine-sol, using special soaps and sprays before a hunt. Heck I was even lining the seat of my truck with pine boughs so as not to make contact with the seat cloth driving in. It got crazy, so crazy, I was stressing constantly and finally realized one day I wasn't having fun anymore. Another big realization was that I wasn't doing any better on the deer as well.

Here's the best part. I have a friend who is a veteran police officer in one of the bigger Michigan cities and he had gotten in with the K9 unit. In a demonstration of a dog's nose ability, which we would all agree is on par with a deer's nose, the department had four of its officers do an experiment. A square mile was located and sequestered for the event. these guys had weeks to prepare for this by scouting the land and being allowed to use anything and everything to kill their scent, cover it, to trick their own family pets. On the day of the event, four officers went into this square mile to hide from their own dogs using every resource at their disposal, including a running stream about 10ft wide. Four hours later, their dogs were released into the same section of land. The longest it took of the four dogs to locate their master was 15 minutes. That really did it for me. I take a reasonable approach these days and hunt the wind proper as the mainstay of my efforts. I stay out of stand sites and woods during contrary breezes or not hunt at all. The results for me have been steady over this timeframe, and better than when I was in the fanatic stage of my career. Just some food for thought all.

 

[dennism]

As much as I respect John, and believe me when I tell you John Eberhart has influenced my hunting technique (and success) more than anyone ever, I have a strong dislike for all types of scent control garments, sprays, or anything pretty much with the possible exception of Buck and Doe Tarsel Gland and fresh deer urine. I feel most of them are gimmicks, and the ones that actually work, work with nominal results.

I truly believe carbon activated suits are oversold as far as ability is concerned. But my primary issue is simply that it is impossible to eliminate human scent completely. So with that said, if a hunter was to eliminate 90% of his or her scent on a given hunt, would a deer, any deer, not be able to smell you if it was to pass down wind.

A few years ago, I was so obsessed with scent control that it literally ruined the joy of the hunt. I was doing it all, keeping clothes outside, isolated from camp smells, washing them in pine-sol, using special soaps and sprays before a hunt. Heck I was even lining the seat of my truck with pine boughs so as not to make contact with the seat cloth driving in. It got crazy, so crazy, I was stressing constantly and finally realized one day I wasn't having fun anymore. Another big realization was that I wasn't doing any better on the deer as well.

Here's the best part. I have a friend who is a veteran police officer in one of the bigger Michigan cities and he had gotten in with the K9 unit. In a demonstration of a dog's nose ability, which we would all agree is on par with a deer's nose, the department had four of its officers do an experiment. A square mile was located and sequestered for the event. these guys had weeks to prepare for this by scouting the land and being allowed to use anything and everything to kill their scent, cover it, to trick their own family pets. On the day of the event, four officers went into this square mile to hide from their own dogs using every resource at their disposal, including a running stream about 10ft wide. Four hours later, their dogs were released into the same section of land. The longest it took of the four dogs to locate their master was 15 minutes. That really did it for me. I take a reasonable approach these days and hunt the wind proper as the mainstay of my efforts. I stay out of stand sites and woods during contrary breezes or not hunt at all. The results for me have been steady over this timeframe, and better than when I was in the fanatic stage of my career. Just some food for thought all.

This is how I feel about it as well. I've been winded while I was in my crazy scent control phase. My best guess on why so many swear by scent loc is that they think they had deer down wind when some milk weed seed would actually show what the wind and thermals are doing.

 

[Sniper4hire]

I'm pretty much a Whitetail fanatic and will do just about anything to get a nice buck (within the law of course), and I really went the mile for scent control for a lot of years. Right about the time the story I told above happened with the police dogs, I also had very nice St. Helen swamp buck, a 10-point come strolling by not a care in the world. I had walked in almost a half mile to my stand and I have a little ritual where I always grind the soles of my knee-high rubber boots into the vegetation when I'm a few yards from the vehicle. To top it off, on this particular hunt, I had to pass through some wet swamp about ankle deep for several yards getting to my stand as well so the boots in theory, should have been about as scent free as they could be. I also put them on at the hunt site and never wear them in the truck.
About four hours had passed from the time I had walked in and this buck shows up, the ground cover in this very spot he would cross my boot prints was dried dirt with sprigs of some kind of spotty vegetation that was no more than 2" tall if that. Anyways, he's mincing along, talking his time and as he crosses my walk-in, three steps from getting a Ramcat through the lungs, he drop his head, sniffs, head comes up, he looks both ways, and somewhat nervously trots out about 30 yds. straight away from me into the swamp/marsh water. He stood at about 50 yds for at least 5 minutes. He wasn't freeking out, just nervous and you could tell by his body language he just knew something wasn't right. He finally took an angled line to the trail he came in on and left the way he'd came. I couldn't believe it. I still can't believe it. I've had this happen before and I'm sure we've all experienced this before, but this time I was amazed. The bottoms of my boots just had to be clean in my mind, plus a 4 hour lapse between me walking in and him crossing my path, WOW!
But again, these days, I still do a reasonable ritual to be clean as possible, I just don't get too crazy. I know my scent just can't be eliminated no matter what I do. Eberhart never hunts the same stand twice, no matter what he sees and by his advice, neither do I. I like him, also save certain set-ups for the rut only. These to me are the key to fooling good bucks and are actually part of a good scent control plan.

 

[redsquirrel]

Eberhart never hunts the same stand twice, no matter what he sees and by his advice, neither do I.

Regardless of what type of scent control one chooses, I am seeing a pattern amongst people who routinely kill big bucks, and this is it.

 

[farmlegend]

Put me down as a believer in the value of scent control. The below thread contains some great discussion on the topic. I particularly concur with the posts by bioactive and BSK_.

http://www.qdma.com/forums/showthread.p ... =bioactive

Scent control truly is a "low hole in the bucket" proposition; if you do nothing but employ carbon clothing, you're really not accomplishing much.

I attempt to practice a high level of scent control. I still will get winded occasionally, however, when I do, it's generally at relatively short distances (in my weaker scent control days, I'd get busted from greater distances), and even when it happens, I can get the "faint scent illusion" working in my favor, as deer appear to react with a mild degree of alarm, then eventually calm down, seemingly convinced that they're picking up distant or otherwise non-threatening human scent.

My experiences lead me to believe that hunters are frequently unaware of their scent busts. Often, the busts occur out of the hunter's sight, and also after the hunter has departed from his stand.

 

[redsquirrel]

That was an awesome link farmlegend. Thanks for sharing that. I agree with everything you said.

This quote from Tap also stood out to me: "I've been 100% convinced for several years that the area around our stands is a "contamination zone" of human odor and that during the night, deer investigate where we've been, and they don't forget where the threat to them is. Mature deer avoid these areas."

3 seasons ago I had a big buck coming in. For whatever reason he stopped right before he hit an opening and decided he didn't like it and just turned around and walked back the way he came. It was the end of october and I tried giving him a couple grunts to convince him to come back. He looked back but kept going. I decided to sit until well after dark to avoid spooking him if he was still close. As I'm sitting there in the dark a huge bodied deer comes from the direction he went and walks over and stops right under my tree. I am 100% convinced that it was the same buck, he waited until after dark and came over to where he heard that grunt to investigate what was going on. Pretty amazing stuff.

 

[CFbowhunter]

Totally new to the forum- and first post. I've been thinking about this so heavily the last few days, I had to post a link to this article I thought was fascinating. First, here's the link: http://www.fieldandstream.com/artic...s-vs-a-drug-dog?dom=fas&loc=hpslider2&lnk=IMG

The article includes links to four separate tests (initiated by field and stream) done with police trained dogs. The article did pretty much what the police veteran friend did in the above post and they did it rather scientifically I thought. The result? Basically found carbon activated AND scent cover sprays held no distinguishable advantage over just walking in as a stinky sweaty mess. As Eberhart and others would probably point out- we don't know how well the carbon activated clothes were cared for, and whether the scent control regimen was actually as thorough as Eberhart and others would have done it. So I still kinda think its up in the air a bit except...

Be sure to read their latest test with Ozonics! WOW! You have to read article to appreciate the difference it made, but it's pretty impressive. I'm sold!

 

[Rg176bnc]

The dog is just tracking the scent though. If you could ask him how long ago did that human come thru what would he say?

Its funny how the dogs always get their man in the shows and tests. I live within 30 miles of a Fed and 2 State pens and I cant remember the last time the dogs found an escapee. Just sayin.

 

[redsquirrel]

Its funny how the dogs always get their man in the shows and tests. I live within 30 miles of a Fed and 2 State pens and I cant remember the last time the dogs found an escapee. Just sayin.

HAHA!

 

[John Eberhart]

For the record on scent control and dogs

If it were possible to have a 150 pound person made of 100% odorless air and have him walk naked from point A to point B in a section of property and then hide, a dog that is trained to follow scent could easily find the 100% odorless man. Some that don't think about things in any depth might ask, how is that possible?

Stop and really think about it for a few minutes! How could an odorless weight walk through an area and be tracked? The answer is very basic.

You remember those mornings when there was dew on the ground when you went hunting. I'm sure most of you have at some point have looked at your back trail and could see where you had walked because the dew was visually to the human eye, disrupted. A trained tracking dog doesn't need a visual.

Whenever ground, grasses and or weeds are disrupted (grass is crushed by the weight, earth under each step is altered from the weight, bases of weeds are broken from the weight) a trained dog can easily follow that path even if there is no other odor whatsoever. To a trained dogs nose there is a huge amount of odor to follow that is different from the rest of the surrounding ground, and that odor is caused by the weight of the 100% odorless man walking and altering the ground with every step.

Let's say the odorless man went down a river through the water for a ways and then got out of the river and went elsewhere. Obviously if a dog were searching the rivers edge, he would immediately know when he passed over the man's path because, again, the altered ground his weight walked on would have a different odor that the surrounding unaltered ground.

I would bet that right after daylight my 8 year old grandson could find a hunter that had walked to his tree through a grass, weed, of green field covered in dew. To us as humans that is an easy visual to follow. Just as we can visually follow the dew disruption to a hunters stand, a dog can easily follow ground disruptions with their trained nose and absolutely no human odor.

My son Chris owned two trained Bavarian Bloodhounds and they could follow anything that left any scent alteration to the surrounding area.

It blows my mind that hunters don't think of these very simple facts, but rather want to spew some BS about a dog finding his master in a field he had just walked through and totally disrupted the ground to where he hid. It's actually pretty funny to me.

Scent control works and I have on many occasions had mature deer walk down my dew altered morning entry route smelling every weed along the way, but not spooking and eventually walking past. Did I think they were following some residual human odor I might have left? Absolutely not. In the heavily pressured areas I hunt, had I left any trace of human odor, they never would have curiously followed the path, they would have immediately spooked.

A proper scent control regiment requires a ton of extra work and to those that are not willing to put in the entire effort or don't know how to do it, it's much easier to slam the proven technology with rhetoric that should be meaningless to anyone that researches things for themselves.

 

[1simplemann]

So I have question, at some point I was told that in order to re-activate the carbon that it takes 800 degrees which would basically melt or burn the suit. Commercial dryers don't even come close to that and the suit will only be partially re-activated. If that's the case, then the suit will be full in no time. I'm no expert,just trying to make sense of some conflicting information.

 

[d_rek]

So I have question, at some point I was told that in order to re-activate the carbon that it takes 800 degrees which would basically melt or burn the suit. Commercial dryers don't even come close to that and the suit will only be partially re-activated. If that's the case, then the suit will be full in no time. I'm no expert,just trying to make sense of some conflicting information.

What you're talking about is incineration not re activation. Think of carbon activated garments as sort of like sponges that soak up your odor as you wear them. When you "re activate" them in the dryer you are essentially "squeezing" some of the trapped human odor molecules out from between the carbon molecules. Remember back to 6th grade science class when we were taught molecules that are heated tend to expand versus contracting when they're cold. So when you re activate the garment you are allowing the carbon molecules to expand and release whatever they have trapped.

Activated carbon is the real deal. My BIL tolde stories of wearing carbon suits on Afghanistan and Iraq because of chemical warfare. Activated carbon prevent something of like 99% of microscopic particulate matter from penetrating the fabric because of its ability to adsorb chemical compounds, including human odors.

I am a firm believer in activated carbon for hunting. I have had way too many deer downwind that didn't spook for this to be more than a coincidence.


Sent from my iPhone using Tapatalk

 

[John Eberhart]

1 simplemann -

There are a lot misinformed hunters that spread unintelligent misnomers about activated carbon concerning how it's produced, to what extent does it work, and can it be regenerated (re-activate is the incorrect term for carbon lined garments) it.

The factual information below should shed some light on the matter of how activated is made and no, I did not write this. This information also did not come from the hunting industry which is an infant in the activated carbon use category. The hunting industry had absolutely nothing to do with the development of activated carbon, they just took advantage of the technology because it is used worldwide in thousands of applications for adsorption and is the most adsorbent substance known to man.

You may also note in the third sentence that activated carbon can go through further chemical treatments to enhance its adsorbing properties. In 2012 Scent Lok did add some (about 33% more) treated carbon to their activated carbon liner making the suit adsorb even better than suits prior to 2012. Also in the text note that all temperatures are in Celsius, not Fahrenheit and 100 degrees Celsius is equivalent to 212 degrees Fahrenheit (the common scale used by US laymen).


The below text came from an activated carbon scientific website:

Activated carbon, also called activated charcoal or activated coal, is a form of carbon that has been processed to make it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions.

[1] The word activated in the name is sometimes substituted by active. Due to its high degree of microporosity, just one gram of activated carbon has a surface area of approximately 500 m² (or about 2.17 tennis courts), as determined typically by nitrogen gas adsorption.

Sufficient activation for useful applications may come solely from the high surface area, though further chemical treatment often enhances the adsorbing properties of the material.

*Production
Activated carbon is produced from carbonaceous source materials like nutshells, wood and coal. It can be produced by one of the following processes:
1. Physical reactivation: The precursor is developed into activated carbons using gases. This is generally done by using one or a combination of the following processes:
-Carbonization: Material with carbon content is pyrolyzed at temperatures in the range 600-900 °C, in absence of air (usually in inert atmosphere with gases like argon or nitrogen)
-Activation/Oxidation: Raw material or carbonised material is exposed to oxidizing atmospheres (carbon dioxide, oxygen, or steam) at temperatures above 250 °C, usually in the temperature range of 600-1200 °C.
2. Chemical activation: Impregnation with chemicals such as acids like phosphoric acid or bases like potassium hydroxide, sodium hydroxide or salts like zinc chloride, followed by carbonization at temperatures in the range of 450-900 °C. The carbonization / activation step proceeds simultaneously with the chemical activation. This technique can be problematic in some cases, because, for example, zinc trace residues may remain in the end product. However, chemical activation is preferred over physical activation owing to the lower temperatures and shorter time needed for activating material.

*Properties
A gram of activated carbon can have a surface area in excess of 500 m², with 1500 m² being readily achievable. Carbon aerogels, while more expensive, have even higher surface areas, and are used in special applications.

Under an electron microscope, the high surface-area structures of activated carbon are revealed. Individual particles are intensely convoluted and display various kinds of porosity; there may be many areas where flat surfaces of graphite-like material run parallel to each other, separated by only a few nanometers or so. These micropores provide superb conditions for adsorption to occur, since adsorbing material can interact with many surfaces simultaneously. Tests of adsorption behaviour are usually done with nitrogen gas at 77 K under high vacuum, but in everyday terms activated carbon is perfectly capable of producing the equivalent, by adsorption from its environment, liquid water from steam at 100 °C and a pressure of 1/10,000 of an atmosphere.

Physically, activated carbon binds materials by Van der Waals force or London dispersion force.
Activated carbon does not bind well to certain chemicals, including alcohols, glycols, strong acids and bases, metals and most inorganics, such as lithium, sodium, iron, lead, arsenic, fluorine, and boric acid. Activated carbon does adsorb iodine very well and in fact the iodine number, mg/g, (ASTM D28 Standard Method test) is used as an indication of total surface area.
Activated carbon can be used as a substrate for the application of various chemicals to improve the adsorptive capacity for some inorganic (and problematic organic) compounds such as hydrogen sulfide (H2S), ammonia (NH3), formaldehyde (HCOH), radioisotopes iodine-131 (131I) and mercury (Hg). This property is known as chemisorption.

Classifications
Activated carbons are complex products which are difficult to classify on the basis of their behaviour, surface characteristics and preparation methods. However, some broad classification is made for general purpose based on their physical characteristics.

Powdered activated carbon (PAC)
Traditionally, active carbons are made in particular form as powders or fine granules less than 1.0 mm in size with an average diameter between .15 and .25 mm.[citation needed] Thus they present a large surface to volume ratio with a small diffusion distance. PAC is made up of crushed or ground carbon particles, 95–100% of which will pass through a designated mesh sieve or sieve. Granular activated carbon is defined as the activated carbon being retained on a 50-mesh sieve (0.297 mm) and PAC material as finer material, while ASTM classifies particle sizes corresponding to an 80-mesh sieve (0.177 mm) and smaller as PAC. PAC is not commonly used in a dedicated vessel, owing to the high headloss that would occur. PAC is generally added directly to other process units, such as raw water intakes, rapid mix basins, clarifiers, and gravity filters.
[edit] Granular activated carbon (GAC)

Granular activated carbon (GAC) has a relatively larger particle size compared to powdered activated carbon and consequently, presents a smaller external surface. Diffusion of the adsorbate is thus an important factor. These carbons are therefore preferred for all adsorption of gases and vapours as their rate of diffusion are faster. Granulated carbons are used for water treatment, deodourisation and separation of components of flow system. GAC can be either in the granular form or extruded. GAC is designated by sizes such as 8x20, 20x40, or 8x30 for liquid phase applications and 4x6, 4x8 or 4x10 for vapour phase applications. A 20x40 carbon is made of particles that will pass through a U.S. Standard Mesh Size No. 20 sieve (0.84 mm) (generally specified as 85% passing) but be retained on a U.S. Standard Mesh Size No. 40 sieve (0.42 mm) (generally specified as 95% retained). AWWA (1992) B604 uses the 50-mesh sieve (0.297 mm) as the minimum GAC size. The most popular aqueous phase carbons are the 12x40 and 8x30 sizes because they have a good balance of size, surface area, and headloss characteristics.

I hope this sheds some light on activated carbon and makes it easy to note that Scent Lok didn't just say, hey let's use this stuff. Activated and treated carbon are extremely high tech materials that have went through extensive tests worldwide in many industries to see which activated carbon works best for specific applications.

As a side note; to 100% re-activate activated carbon it must be sent through the same process it went through to make it in the first place, meaning the high temperatures in the absence of air. This is called industrial reactivation that brings it back to its original state with no molecules bonded to it whatsoever. This is not required for hunting garments that only need occasional partial regeneration to make room for more adsorption (this was proven in the lawsuit against Scent Lok that went through a United States Federal court). Can be simulated to wringing out a wet sponge. The sponge is still holding moisture but there is room after wringing the sponge out for more adsorption.

This is a photo (under an electron microscope) of a particle of activated carbon to show its porosity. Keep in mind that this carbon particle is smaller than a grain of sand.

 

[1simplemann]

1 simplemann -

There are a lot misinformed hunters that spread unintelligent misnomers about activated carbon concerning how it's produced, to what extent does it work, and can it be regenerated (re-activate is the incorrect term for carbon lined garments) it.

The factual information below should shed some light on the matter of how activated is made and no, I did not write this. This information also did not come from the hunting industry which is an infant in the activated carbon use category. The hunting industry had absolutely nothing to do with the development of activated carbon, they just took advantage of the technology because it is used worldwide in thousands of applications for adsorption and is the most adsorbent substance known to man.

You may also note in the third sentence that activated carbon can go through further chemical treatments to enhance its adsorbing properties. In 2012 Scent Lok did add some (about 33% more) treated carbon to their activated carbon liner making the suit adsorb even better than suits prior to 2012. Also in the text note that all temperatures are in Celsius, not Fahrenheit and 100 degrees Celsius is equivalent to 212 degrees Fahrenheit (the common scale used by US laymen).


The below text came from an activated carbon scientific website:

Activated carbon, also called activated charcoal or activated coal, is a form of carbon that has been processed to make it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions.

[1] The word activated in the name is sometimes substituted by active. Due to its high degree of microporosity, just one gram of activated carbon has a surface area of approximately 500 m² (or about 2.17 tennis courts), as determined typically by nitrogen gas adsorption.

Sufficient activation for useful applications may come solely from the high surface area, though further chemical treatment often enhances the adsorbing properties of the material.

*Production
Activated carbon is produced from carbonaceous source materials like nutshells, wood and coal. It can be produced by one of the following processes:
1. Physical reactivation: The precursor is developed into activated carbons using gases. This is generally done by using one or a combination of the following processes:
-Carbonization: Material with carbon content is pyrolyzed at temperatures in the range 600-900 °C, in absence of air (usually in inert atmosphere with gases like argon or nitrogen)
-Activation/Oxidation: Raw material or carbonised material is exposed to oxidizing atmospheres (carbon dioxide, oxygen, or steam) at temperatures above 250 °C, usually in the temperature range of 600-1200 °C.
2. Chemical activation: Impregnation with chemicals such as acids like phosphoric acid or bases like potassium hydroxide, sodium hydroxide or salts like zinc chloride, followed by carbonization at temperatures in the range of 450-900 °C. The carbonization / activation step proceeds simultaneously with the chemical activation. This technique can be problematic in some cases, because, for example, zinc trace residues may remain in the end product. However, chemical activation is preferred over physical activation owing to the lower temperatures and shorter time needed for activating material.

*Properties
A gram of activated carbon can have a surface area in excess of 500 m², with 1500 m² being readily achievable. Carbon aerogels, while more expensive, have even higher surface areas, and are used in special applications.

Under an electron microscope, the high surface-area structures of activated carbon are revealed. Individual particles are intensely convoluted and display various kinds of porosity; there may be many areas where flat surfaces of graphite-like material run parallel to each other, separated by only a few nanometers or so. These micropores provide superb conditions for adsorption to occur, since adsorbing material can interact with many surfaces simultaneously. Tests of adsorption behaviour are usually done with nitrogen gas at 77 K under high vacuum, but in everyday terms activated carbon is perfectly capable of producing the equivalent, by adsorption from its environment, liquid water from steam at 100 °C and a pressure of 1/10,000 of an atmosphere.

Physically, activated carbon binds materials by Van der Waals force or London dispersion force.
Activated carbon does not bind well to certain chemicals, including alcohols, glycols, strong acids and bases, metals and most inorganics, such as lithium, sodium, iron, lead, arsenic, fluorine, and boric acid. Activated carbon does adsorb iodine very well and in fact the iodine number, mg/g, (ASTM D28 Standard Method test) is used as an indication of total surface area.
Activated carbon can be used as a substrate for the application of various chemicals to improve the adsorptive capacity for some inorganic (and problematic organic) compounds such as hydrogen sulfide (H2S), ammonia (NH3), formaldehyde (HCOH), radioisotopes iodine-131 (131I) and mercury (Hg). This property is known as chemisorption.

Classifications
Activated carbons are complex products which are difficult to classify on the basis of their behaviour, surface characteristics and preparation methods. However, some broad classification is made for general purpose based on their physical characteristics.

Powdered activated carbon (PAC)
Traditionally, active carbons are made in particular form as powders or fine granules less than 1.0 mm in size with an average diameter between .15 and .25 mm.[citation needed] Thus they present a large surface to volume ratio with a small diffusion distance. PAC is made up of crushed or ground carbon particles, 95–100% of which will pass through a designated mesh sieve or sieve. Granular activated carbon is defined as the activated carbon being retained on a 50-mesh sieve (0.297 mm) and PAC material as finer material, while ASTM classifies particle sizes corresponding to an 80-mesh sieve (0.177 mm) and smaller as PAC. PAC is not commonly used in a dedicated vessel, owing to the high headloss that would occur. PAC is generally added directly to other process units, such as raw water intakes, rapid mix basins, clarifiers, and gravity filters.
[edit] Granular activated carbon (GAC)

Granular activated carbon (GAC) has a relatively larger particle size compared to powdered activated carbon and consequently, presents a smaller external surface. Diffusion of the adsorbate is thus an important factor. These carbons are therefore preferred for all adsorption of gases and vapours as their rate of diffusion are faster. Granulated carbons are used for water treatment, deodourisation and separation of components of flow system. GAC can be either in the granular form or extruded. GAC is designated by sizes such as 8x20, 20x40, or 8x30 for liquid phase applications and 4x6, 4x8 or 4x10 for vapour phase applications. A 20x40 carbon is made of particles that will pass through a U.S. Standard Mesh Size No. 20 sieve (0.84 mm) (generally specified as 85% passing) but be retained on a U.S. Standard Mesh Size No. 40 sieve (0.42 mm) (generally specified as 95% retained). AWWA (1992) B604 uses the 50-mesh sieve (0.297 mm) as the minimum GAC size. The most popular aqueous phase carbons are the 12x40 and 8x30 sizes because they have a good balance of size, surface area, and headloss characteristics.

I hope this sheds some light on activated carbon and makes it easy to note that Scent Lok didn't just say, hey let's use this stuff. Activated and treated carbon are extremely high tech materials that have went through extensive tests worldwide in many industries to see which activated carbon works best for specific applications.

As a side note; to 100% re-activate activated carbon it must be sent through the same process it went through to make it in the first place, meaning the high temperatures in the absence of air. This is called industrial reactivation that brings it back to its original state with no molecules bonded to it whatsoever. This is not required for hunting garments that only need occasional partial regeneration to make room for more adsorption (this was proven in the lawsuit against Scent Lok that went through a United States Federal court). Can be simulated to wringing out a wet sponge. The sponge is still holding moisture but there is room after wringing the sponge out for more adsorption.

This is a photo (under an electron microscope) of a particle of activated carbon to show its porosity. Keep in mind that this carbon particle is smaller than a grain of sand.

I'm glad you responded. Since your the one that got me thinking about this stuff. I was going to call you but I figured you'd be hunting hard and I didn't want to interupt. BTW Nice buck! After talking on the phone w/ you the other day(BTW, I did get a 6x6 bull that evening and they were screaming! 2nd estrousm like I mentioned.), I've been checking this stuff out.Yes ,that does shed some light. It's a lot to take in. You and your record speak volumes in favor of this stuff. Which carries some serious weight with me. It's the other stuff I've heard over the years that keeps hanging me up. I've heard the same thing that you mentioned, to 100% re-generate the carbon,extreme temps would be needed. Too hot for the clothing to handle. You say it's not needed, only a partial regeneration needed. I've been told the carbon does work but is basically full by the time it's leave the store and for sure will be full within a few uses. I've also been told the regeneration process is less effective after each time and soon will not regenerate rendering it useless therefore a waste of money. This is only what I've been told and shown at Deer expo I once attended. Basically I was told it was a scam and never gave it another thought till now. Originally I was thought it may possibly be your other scent control measures that could be difference and not the scent lok. There have been times where I felt I did an exceptional job at scent control and had deer walk downwind and NOT blow off. I just chalked that one up to me and my equipment being very clean. I have to be honest sometimes I'm a little lazy or don't have enough time etc. Those times, I'm just hoping that I'm playing the wind right. I'm definitely going to have to be more diligent in that area. In reading your books you mention though that things didn't start to really click until you ADDED Scent Lok and included it as part of you regimen. For me, that might just be what tips me over hump. If I indeed do purchase a suit, what does a guy buy?
Anything in particular? Does brand matter? Thanks in advance,
Rob in Montana

 

[John Eberhart]

Rob

First off hunters that spout off against activated carbon have no clue what their talking about, have no interest in researching activated carbon technology, are too lazy to properly care for it and do everything else in conjunction with it, and definitely haven't a clue what they spew about low heat regeneration.

I can give you a simple and visual example of how activated carbon regenerates using very low temperatures. Heat causes molecules to energize or in other words expand. We as humans can visually see expansion joints in concrete highways and is steel bridges amongst many other things. Trust me when I state that concrete highways and steel bridges never see temperatures over 110 degrees and let it also be known that the concrete and steel begin expanding on sunny days when temps are in the 70's. If the expansion joints weren't there the concrete would buckle from the expansion and the steel would bend if it had no expansion area to expand into. Human odor molecules and the activated carbon their lightly bonded to also energize under low heat and a percentage of the human molecules break free from the carbon and escape out the dryer vent making more room for adsorption again. Very simple and plain to understand.

A gazillion degrees is only required for total re-activation which is removing all bonded (industrial re-activation).

 

[1simplemann]

Makes sense to me. I appreciate the response and time. Any thoughts to the questions I asked at the end of my last post?