Char cloth success and failure

[draktar]

Hey everyone, I am new here so first of all....nice to meet you all.
I have been learning how to use a flint and steel and have gotten pretty good at starting a fire with pre-made cloth. I have researched making my own cloth for some time now and I have made it successfully and unsuccessfully. At first I used an altoids tin but I didn't really pay much attention to all the variables. Now I am looking at it as a science experiment. I have used 100% cotton, punk wood, altoids tin with a hole, without a hole, with a nail inserted after taking it out and without the nail. I have also used a tin purchased from a vendor that is probably 2 1/2 x 2 x 8 inches around with a very small hole in the top. I have tried using a few pieces of cloth and more (between 4 on 2 inch squares and 8) My last results were a no go on the altoids tins at all and they have worked in the past, and the vendor tin worked. I used bulk 100% cotton material from walmart in the altoids tins and an old shirt and some cotton from the vendor in the larger tin (the one that worked). I put a nail in the hole after I took the vendor tin out.
As far as how long to leave the char in the fire....I have read or seen 6-10 minutes which is a big difference and also those who say when the smoke is done coming out of the tin then its done. The problem with no hole in the altoids tin is that its hard to see when it stops smoking in a fire at night. I have tried the smoke test and various time limits as well as stages of heat in the fire. What I am getting is char cloth that is black not ash and wont ignite even with a fire steel. When it works I get a light on the first flint and steel strike. Ideas?
To narrow this long post down (sorry)
1) Altoids tin- how long do you leave it in?
2) With or without a hole- I know that the tin is not air tight
3) What could cause char to not ignite- mine is completely black -no brown- I guess this is the big question!
4) How much cloth do you put in at one time

[Stiffy]

I've never used an Altoids tin. I use larger tins, such as decorative cookie tins I find at garage sales. I use a hole and just go by the smoke . . . when it stops smoking, I take it out of the fire and plug the hole with a nail.

Most of my attempts have come out fine. As far as the material, I used cheap cotton cosmetic wipes successfully, but now I'm using monk cloth. I bought a yard of it at Walmart for about eight dollars and cut it into three inch squares. Depending on the size of your "yard," that's about 144 squares.

[draktar]

I've never used an Altoids tin. I use larger tins, such as decorative cookie tins I find at garage sales. I use a hole and just go by the smoke . . . when it stops smoking, I take it out of the fire and plug the hole with a nail.

Most of my attempts have come out fine. As far as the material, I used cheap cotton cosmetic wipes successfully, but now I'm using monk cloth. I bought a yard of it at Walmart for about eight dollars and cut it into three inch squares. Depending on the size of your "yard," that's about 144 squares.

Thanks! I will give the monk cloth a try. I never thought about using cosmetic wipes. Im sure the wife has a few lying around.

[intothenew]

Here's another thread that you may gain some insight from.


LINKY

[Stiffy]

Thanks! I will give the monk cloth a try. I never thought about using cosmetic wipes. Im sure the wife has a few lying around.

Just make sure they are 100 percent cotton. They worked great, but I stopped using them because they are so light weight. Once they catch a spark they don't last long. I had best results by stacking two or three together before striking my flint.

[Old Professor]

I also use a larger cookie type tin to make char cloth. I personally prefer cotton gun cleaning patches, which come in a variety of sizes. I have one hole in the lid and place the tin over a charcol grill until smoke stops coming out the hole. I am thinking of trying making them in my prophane smoker because I could control the heat so well. After the smoke stops, I remove the tin from the heat and let it cool. Turns out excellent char cloth!

[PineMartyn]

Hello Draktar, You said you wanted to proceed in a scientific manner, so below is a rather detailed explanation of charring which, I believe, will explain why your charred cloth is sometimes not taking sparks or holding embers properly, as well as answer your other question specific questions. It's all a matter of understanding what charring is.

Charring is supposed to be an anaerobic process. Chemically speaking, it is known as pyrolysis and, as such, no air should get into the charring tin. Here's how it works:

When the tin is in the fire or on the coals, gases are produced which build up inside, creating a high pressure system within, and these gases, along with the air originally in the tin, are forced out by this internal pressure, preventing outside air from entering it. Once the gases have been mostly expelled, there is no longer an outward flow of gas from the tin to keep outside air from flowing into the tin; the anaerobic charring process ceases, and an aerobic combustion process takes over. If you leave your tin in the fire too long, air will get in. This is particularly important once the tin is sitting and cooling outside the fire. A properly charred material, once it's removed from the fire, can be ruined while it's cooling as oxygen from the air outside rushes into the super hot tin and begins consuming the combustible material within.

If you make a lot charred cloth, you will sometimes get batches where the cloth won't take a spark easily, or sometimes it will take a spark well, but peeters out prematurely. If ever you find your charred cloth is crumbly, tears apart from even casual handling, or if it's sooty and blackens your fingers when touched, this means that too much air has gotten in and your cloth has gone beyond merely charring and became partially burned. The more it's burned, the less combustible material remains in the cloth to hold and grow as an ember. As stated above, this consumption of the combustible material can happen while it's on the fire after the heated gases have all escaped and, just as easily, once the tin is removed from the fire to cool. The more air gets in while the tin is hot, the more of the combustible material is consumed in an aerobic chemical reaction, and it's the uncombusted material which takes and holds a spark and which then spreads as an expanding ember.

Below are some photos I took of me making charred cloth in my fireplace at home using a very old Voyageur's technique for ensuring that the process is anaerobic from start to finish, producing good quality charred cloth consistently. I take no credit for developing this technique. It's age-old.

You will note a tiny hole in the lid of the tin. This hole, made with a small nail or awl, permits the air in the tin at the outset to escape along with the rest of the gases which will be produced as the cloth is charred. When the charring begins, smoke will vent out. This is a sure sign no air is entering the tin. Air simply can't get in while heated gases vent out.
01.jpg

When the smoke ceases puffing out the hole, wait about 30 seconds longer (no more), then tip the tin over so it rests upside down on the coals. This is done because the cloth in the lower half of the tin will have charred more completely than the top, since it was in closer contact with the hot coal bed. Turning it over permit the cloth on the top to char as well, producing a more evenly charred batch.

In this photo, you can see smoke pouring out a hole punch in the bottom. Once again, let smoke vent out the bottom. There will be less smoke, but any amount of smoke emerging proves it wasn't thoroughly charred yet.
05.jpg

Once smoke stops venting from the bottom, remove the tin from the fire, and immediately take two short twigs, each whittled to a point, and plug the top and bottom holes. Leave the tin resting on it's side to cool.
06.jpg
This is the critical step that ensures hardly any air can get into your tin and ruin the now completely charred, but unburned cloth. Let it cool completely before removing the plugs and opening the tin. If you open it too soon, the sudden inflow of oxygen into the tin can actually cause the cloth to burst into flames (if it's still very hot) or, minimally, use up some of the combustible material until it cools down enough for that reaction to stop.

07.jpg

The photo below shows the charred cloth. This batch was made from a thin, worn out cotton t-shirt. Notice that the piece in my right hand is so thin you can just barely see my finger through it in places...but it's not fragile, crumbly, or sooty to the touch. Even with cloth this thin I am able to peel apart the stacked layers without fear of shredding them up. It's charred, not burned. This stuff will take a spark and hold an ember every time. And even when it's this thin, it makes a hot ember because the combustible material is still all there, unconsumed. The purpose of charring is to make the consumable material more combustible, to lower it's kindling point, not consume the combustible material beforehand.
10.jpg

I recommend this method to any who have wondered why some of their batches of charred cloth vary in efficacy. It's probably not the cotton you're using, it's certainly not how thick or dense it is, it's the air that's getting into your tin, which varies from one attempt to the next. Choose a container that closes tightly. Punch tiny holes in the top and bottom to let gases escape and signal when the charring is complete, and plug the holes as soon as you remove the tin from the fire. Making it as anaerobic a process as possible will yield a better quality of charred cloth on a consistent basis. No more partially charred (browned) or over-cooked material.

I'll be uploading a YouTube video explaining and demonstrating this principle in a little while.

Hope this helps and keep playin' with fire!
- Martin

[draktar]

Hi Martin,
WOW! Thanks for the info! I had a feeling it had to do with either air, time, or temp. It seems like I was making the mistake of too much time and now I know that plugging the hole is a must. What I really needed to know was all the info about the appearance of the cloth after the fact. Does it matter how hot a fire you use.....coals vs full on fire? Also how much cloth do you put in when you make your char. I read about this method but there was no mention. Thanks again!
Jason

[PineMartyn]

Hi Martin,
WOW! Thanks for the info! I had a feeling it had to do with either air, time, or temp. It seems like I was making the mistake of too much time and now I know that plugging the hole is a must. What I really needed to know was all the info about the appearance of the cloth after the fact. Does it matter how hot a fire you use.....coals vs full on fire? Also how much cloth do you put in when you make your char. I read about this method but there was no mention. Thanks again!
Jason

You're very welcome Jason. I'm glad you found it informative.
It's overstating it to say that "plugging the hole is a must". It's a must if you want good quality charred cloth on a consistent basis, but people can and have made charred cloth for ages without understanding the process and letting air in. If air gets in, it usually works well enough, that's introduce an element of luck to the procedure. If survival and readiness is the goal, having charred material that will work reliably is especially important. If one is in the habit of using a ferro-rod to throw sparks onto one's charred cloth, one might never know that the product is not very good. But if you're using a flint and steel, which throws much weaker sparks, having a charred material that's not partially burned makes all the difference. Making it anaerobically just takes the luck and guesswork out of the quality of the product.

As to your question of the appearance, it should look black - flat black. It should not be crumbling, tearing when you handle it, or leaving your fingers sooty. Anything that's browned is not sufficiently charred. Oddly enough, when air gets in the tin, you can get material that's partially brown (insufficiently charred) and partially black (burned). One of the causes of browning is over-packing the tin. You don't need to cram a lot in there. Just cut enough to fit loosely in the tin. Cutting long strips and rolling it up and putting the roll in a tin also tends to pack the material together too tightly, leading to a brown product.

You needn't worry about the temperature of your fire. If you have coals of any sort of wood - even fast-burning soft woods - it will work just fine. Just make a bed of glowing coals and rest the tin on it as I described above. You can put the tin directly into flames and it will work just as well, but the difficulty there is that it's sometimes hard to see the little puff of smoke issuing from the vent hole because of the flames and other smoke from the fire. It's also easier to tip the tin over with a stick when the time comes if it's sitting on a coal bed.

A lot of people get frustrated and puzzled because they think it's the tin they used, or the heat of the fire was wrong, or the type or thickness of cotton they used, etc. But if you understand the anaerobic nature of pyrolysis, you will be able to get good stuff with even the thinnest cotton material, even fine linen. And remember, you can char natural materials as well. Punky wood chars very well, so if you don't have cloth on you in the bush, you can always char bits of dry punky wood in your tin.

Hope this helps,
- Martin

[randyt]

I use old cotton blue jean material for my char cloth and for plugging the smoke hole, a stone is usually set over it.

[wildgarlic]

You are making carbonaceous coke in coth form. Use 100 percent cotton and a small hole, you do not want air inside. You want basically a carbon cloth. If too much air gets inside it will be brittle and fall apart. A small hole at best

[tjwilhelm]

Great write up, Martin!

For fun, however, it does not have to be made in a closed tin with a small hole. I sometimes make it in a simple "gasification" stove. It made sense to me that it should work, I tried it, and it did! Here's a vid:

[PineMartyn]

Great write up, Martin!

For fun, however, it does not have to be made in a closed tin with a small hole. I sometimes make it in a simple "gasification" stove. It made sense to me that it should work, I tried it, and it did!

Thanks tjwilhelm. Nice video. I've never seen charring made with a wood gassifier. Very cool experiment.

You're correct, of course, that one can produce charred material without a tin. Eliminating oxygen using a closed metal tin just maximizes the percentage of combustible material for a better quality product. The most primitive way of charring involved no tin and no cloth at all. Natural plant materials, such as punk wood, were wrapped in tied layers of green leaves or placed into clay pots and put onto a coal bed, then the bundle or clay pot were removed from the coal bed and buried in dry sand or in a larger pot or vessel of dry sand to cut off the air while material continued to char and cool off. So, using metal tins and fabrics was a much more recent innovation, handed down to us today because it produced a more reliable and easy to use form of charred material.

Hope this helps,
- Martin

[draktar]

Thanks for all the valuable information guys!