How to Make Char Cloth With a Tuna Can




Introduction: How to Make Char Cloth With a Tuna Can

About: Random Weekend Projects

I sacrificed my kids clothes and a can of tuna to make some high quality fire starter!  Here's how to make a great batch of Char-Cloth to add to your emergency kit.

Step 1: Watch the Video!

WARNING: This project should not be attempted without adult supervision and adequate training.  Misuse, or careless use of fire and flammable materials may result in serious injury, property damage, and/or death.  Use of this video content is at your own risk.

Step 2: What Is Char Cloth?

Char-Cloth is a fire starting tinder that has the ability to capture and hold a spark amazingly well, and for a considerable amount of time.

According to Wikipedia;

"Char cloth (also called charpaper) is a swatch of fabric made from vegetable fiber (such as linen, cotton or jute) that has been converted via pyrolysis into a slow-burning fuel of very low ignition temperature.

It is capable of being ignited by a single spark that can in turn be used to ignite a tinder bundle to start a fire.

It is sometimes manufactured at home for use as the initial tinder when cooking or camping and historically usually provided the "tinder" component of a tinderbox. It is often made by putting cloth into an almost airtight tin with a small hole in it, and cooking it in campfire coals until the smoking slows and the cloth is properly charred.

Charcloth ignites with even the smallest spark, and is therefore commonly used with a flint and steel."

I use it as my tinder of choice my acrylic fire piston.

Step 3: Materials You'll Need

This project can be done with items you probably already have around the house!

  • 1. Tuna Can
  • 2. "Lid lifter" style can-opener
  • 3. Nail, punch, or small screwdriver
  • 4. Cotton fabric
For cotton fabric, old T-shirts work very well if they're 100% cotton.  You can find this information on the tag inside the shirt.

I also found that cotton balls work extremely well, and have become my new favorite!

Step 4: Cook the Cotton

To make the Char Cloth cooker, just follow these steps;
  1. If possible, use a "lid-lifter" style can-opener to open the can.  This cuts the top off along the side of the can.
  2. Clean out your tuna can and make sure it's dry and free of contaminants
  3. Place 4-8 cotton balls inside the can (Or about 4 round pieces of cotton fabric from your T-shirt)
  4. Replace the lid and press it back into place.  (Note: If you cut it with a "lid-lifter" style can opener it should press and hold together like it was meant to be!)
  5. Flip the can over, and use your punch to make a small hole in the "top" of the cooker
Your cooker is complete and ready to go!

Step 5: Fire It Up!

The goal is to heat the container up over 400C, and this can be done in a variety of ways.  For example;

  • 1. Use solar power via your Solar Scorcher from another project
  • 2. Place directly in an open flame
  • 3. Any other outdoor method of inducing heat.  (Outdoors because potentially harmful gasses will be released and can smell up your house)
When the container gets hot enough, the cotton releases gasses, including hydrogen and methane gases.  As these gasses are cooked out, the fiber becomes carbonized through a process called "pyrolysis".  This means that the fiber is charred, but not burned.

You can tell the process is working because you'll see the gas venting through the hole in the top of the container.  These gasses are flammable, and may ignite.  Don't worry if they do because that's normal and just fine.

The cooking is done when the gas stops and the flame goes out.

Note: I've found that cooking them beyond the point where the gasses stop, and flame goes out, can negatively effect their performance, so take the container off the fire as soon as practical.


  • Place a layer of aluminum foil over the hole to prevent air from sucking back into the container.  
  • Let cool for about 5 minutes

Note: The container is very hot, so use protection on your hands to avoid being burned while applying the foil.

Step 6: How Did It Turn Out?

When the container has cooled off completely, open it up and the first thing you'll hopefully see is that your white cotton fabric (or cotton balls) have turned completely black.

Note: If there are parts that are still white, or brown, it's not cooked completely and needed more time on the fire.

To test your batch of char-cloth, brush gently with an open flame.  The cloth should capture the heat and form a small spark that will continue to smolder for an impressive amount of time.  1 cotton ball can last a couple of minutes.

By blowing air onto the spark, heat will transfer quickly and can engulf the entire cloth.

This is the great advantage of the cloth.  It can deliver a lot of heat when you need it (by blowing on it), or just hold a spark for a couple of minutes while you're getting your tinder bundle ready.

Step 7: In Closing

Well there's how to make a batch of char-cloth using materials from around the house.  It's great for emergencies, so go make a batch for your emergency kit right now!

Haven't see the video yet? You can still see it here!

If you like this project perhaps you'll like some of my others. Check them out at



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66 Discussions

I tried this in an Altoid can on the grill side of a BBQ and it worked really well.

Does char-cloth take a spark as well or better than a cotton ball impregnated with paraffin?

1 reply

I haven't tried sparking cotton that's been coated in wax, but I have with charcloth, and even a novice like me can start a fire with it. I'd never started a fire before with a ferro rod, but after I made charcloth, it only took one try and I had it.

nice instructable, however there's no need to pierce it. look up "Flint and Steel Char Cloth Tin - Does It Really Need a Hole?" on youtube and watch it. he proves it don't, even with a cavandish & harvey tin which has a rather tight fitting lid.

What a good way to store char-cloth/ball in a backpack until it's needed?

Well done. And that magnifying glass!!!

My dad would love this

if they get wet will it affect the durability or effectivness of a char cloth in any way? (in other words is it waterproof)?

1 reply

The nice thing about army surpluses gun cleaning patches is they are per cut to one inch peices

I have found that an Altoids can and the army surplus gun patches (100% cotton) work great. I don't let the smoke catch on fire I usually make mine over embers and I take it off and let it cool after the smoke stops. I cover the hole when cooling, it doesn't hurt ;)

My personal recommendations, I've done it a few times before,
First, I would recommend just using a fire, and watch the smoke. I've never noticed flames out of the hole, just watch when the smoke turns from gray to white. Then take out of the fire and let it cool.
I've also never covered the hole and have never had a Flashback with it, And I don't believe it would be a problem so long as you keep it away from the fire.

1 reply

Use a wooden kebob stick, sharpened stick or pencil to seal your hole after charring--the AL foil is too complicated and wasteful.

4 replies

dig a hole, fill it with wood or whatever, then cover it with dirt to keep air out and heat until it stops smoking. there would be more to it of course, like how do you heat it (probably by building a fire on top of it), but that's the general idea. as a matter of fact, the idea probably came from char left over in just a regular fire. they noticed that some of the larger pieces at the heart of the pit (where oxygen was harder to come by) didn't fully consume and were really easy to re-light. just speculation.

This is actually a fascinating piece of history that is not well documented. What you are implied making is char wood, not far off from char cloth, the subject of this Instructable. I did some Googling and found all sorts of speculation and very good guesses as to how this came about. What one must ask is: why hasn't some history graduate student written a dissertation on this given the amount of uncertainty.

Apparently, what we are talking about in general is tinder, and there are a significant number of artifacts out there in regards to it. One of the more interesting is the notion of a tinder stick, which is a metal tube that has a cotton (or linen, or jute) cord in it. You light one end of the cord, let it burn and then pull it back into the tube, which extinguishes it and makes it into tinder. Then, when you need a bit you push the charred end out and go to it. Isn't technology wonderful?

The thing that must be remembered is that in the days before electricity, the primary energy source for heating and cooking, and to some extent light, was wood fires. Making them was a daily thing and technologies evolved to support the process.