The Spirit Lantern (Green Fire 2.0)

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Introduction: The Spirit Lantern (Green Fire 2.0)

Green fire is ubiquitous on the web, and making it is remarkably straightforward - provided you are not led astray, as I was, by ... let's call it poetic license.

Now, after having had a rather disappointing Halloween at chez Green, when I read that a purported "chemistry teacher" found using isopropyl alcohol, rather than methanol, resulted in "a fire that alternated from orange to blue to green" and that it was "pretty cool," I now understand that to mean "after the third whippit, the normal blue and orange flames of the rubbing alcohol looked kind of green. Then I passed out."

The rules of making green fire are as simple as they are inviolate:

1) use methanol

2) add boric acid

The reason for these rules lies in ... chemistry! Here is the chemical equation for the boric acid/methanol reaction:

H3BO3 (boric acid) + 3CH3OH (methanol) --> B(OCH3)3 (trimethyl borate) + 3H2O (water!)

A very small amount of the boric acid is transformed into the trimethyl borate, but as the flame of methanol burning is a very pale blue, the borate compound easily overwhelms it.

I found that I was dissatisfied with the usual approach of making a puddle of liquid and setting the puddle on fire. First of all, the fuel is used up quickly. Secondly, it's hard to control and makes a big mess. For these reasons, I decided to make a small lamp for my green fire for a more controlled, portable and neater illumination.

For this instructable, you will need the following:

* Methanol (Heet - yellow bottle - is an easy source of this) $2.00
* Boric acid (you can find this in the hardware store as an insecticide, but I ordered it through a pharmacy to ensure that the product was not overly contaminated with unwanted chemicals) $5.00
* lamp wick (small round is easier to work with than large flat variety) $2
* small, "sampler size" jam jar
* an electric drill with a drill bit slightly smaller than the diameter of the wick
* (optional) a small hurricane lamp for a votive candle (I found one for $.50 at a thrift store)
* (optional) the metal holder from a spent votive candle

Safety notes:

Alcohol is flammable, and alcohol vapors are explosive if concentrated and lit. Use good sense. One of the reasons for the small jam jar is that only a small amount of alcohol will spill if the jar is dropped and breaks. Also, try not to get methanol on your skin, as it can be absorbed through the skin, and is not nice. Never drink methanol. It is toxic, and cannot be made "untoxic." Think *permanent blindness*.

Boric acid is fairly innocuous, but inhaling large amounts of it (or swallowing it, or getting it in your eyes, etc) will not feel nice.

Green fire produces a white "smoke" that is actually diboro trioxide. It's (evidently) fairly harmless, but makes a mess. The Spirit Lantern is best used outdoors.

Step 1: Step 1: Make Green Fire!

In a jar, bowl or other receptacle, add 1 teaspoon of boric acid and pour roughly a quarter cup of methanol. Agitate, stir or shake this mixture, as applicable to your container-type, until the boric acid is largely dissolved (see third picture). As you can probably guess from the measurements, this is not an exact, stoichiometric ratio. That's okay. We're not all "chemistry teachers."

Now, cover your proto-green fire, and set it aside. Do NOT light up a cigarette to relax after mixing. Do not taunt green fire!

Let's make the lantern.

Step 2: Step 1a: Test Green Fire! (optional)

I know it's hard to wait. And after all, it's YOUR green fire, so why wait anyway? Take a small amount of the mixture, pour it into the jam jar, and light it on fire! It's green!

After blowing it out, you will see the white B2O3 residue on the sides of the jar. Fortunately, it comes off easily, so once you complete your lantern, you will still have a pristine-looking jar.

Step 3: Step 2: Make the Lantern

Now, on to the lantern.

First, sand or otherwise remove all of the paint or decorations from the jar lid, and remove the label from the jar. The first of these steps is to avoid burning whatever is in the paint on your jar lid, which could include fairly nasty things; the latter is just to make the jar look nicer.

Now, using your drill and a drill bit that is slightly smaller than the diameter of your wick (I used 3/8 inch), drill a hole in the lid of the jar. Drill from the outside of the lid. This will keep any burrs on the inside of the lid, where they can't cut you. Do not remove the burrs however. You will be needing these.

Now insert your wick. You'll want 1/4 to 1/2 an inch outside the jar, and enough inside the jar to reach the fuel. Allowing a little to coil at the bottom is good, but a lot of wick will just soak up the liquid. Once the wick is inserted, you can gently (and carefully) press the burrs into the wick to help hold it in place.

Now fill up your lantern and look at it. Isn't it pretty!

Step 4: Step 3: Test the Lantern

At this point, it's reasonable to test the lantern, and it's probably okay to do this inside. You're not going to keep it alight for very long, and the mess should be minimal.

You'll note that, unlike store-bought lanterns, there is no mechanism to pull more wick out, when it burns down. Your options are to either blow the fire out, and pull the wick out by hand, or to use metal tweezers or tongs to pull more wick out while the lantern is lit.

Step 5: Step 4: the Completed Lantern!

At this point, go ahead and add your hurricane lamp and place the Spirit Lantern on a plate, bowl or other holder. It's nice if the holder is metal and shiny, as this adds to the effect. If you aren't able to find an appropriately-sized hurricane lamp, you could use a larger jar. Just make sure to use tongs or a grill lighter so you don't burn yourself. Methanol burns hot.

I placed mine on top of a metal bowl. I don't recommend this, as it's not very stable, but it made for a nice composition.

As a final touch, you can use an empty (burned out) votive holder as a snuffer, or to keep alcohol vapors from escaping from the lantern when not in use.

The amount of light these give off is not great, but what they lack in utility, they more than make up for in ambiance.

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    34 Comments

    For the record, I am aware that the chemical equation above is not properly balanced. Unfortunately, I seem to be having trouble with the editor function on the site. The correct formula is as follows:

    H3BO3 (boric acid) + 3CH3OH (methanol) --> B(OCH3)3 (trimethyl borate) + 3H2O (water!)

    Also, on one of the later pages, I write that you should use sandpaper to remove pain. I sincerely apologize for this misinformation. No amount of sanding will take away the pain. However, it can be helpful in removing paint. Again, the editor function is preventing me from correcting this typo.

    Illinois Cub Scouts Burned in Chemical Explosion

    http://www.nbcchicago.com/news/local/illinois-cub-scouts-burned-chemical-explosion-279886642.html

    That children got hurt doing this is very sad. However, for the record, I stated in the warnings on page 1 that "Alcohol is flammable, and alcohol vapors are explosive if concentrated and lit." If you have some thoughts on a safer way to do this, please make your own Instructable - I will be happy to link to it. I will say that, when it comes to pyrotechnic-related accidents, the CPSC's latest data shows that over 11,000 people were injured using professionally-manufactured fireworks in 2013. That might be a more pressing issue on which you could spend your time.

    cool, but there is an easier an safer way to get a green flame by throwing green sparklers in a fire :) I'm still going to try it though 3:)

    Erm...Methanol is also toxic. http://en.wikipedia.org/wiki/Methanol#Toxicity
    Maybe you should try Ethanol.

    Burning methanol won't hurt you unless you drink it. Probably is safe enough for that use as is ethanol and the solubility of boric acid is much higher.


    The same doesn't hold true about the boric acid and you may realize years later.

    I'm a chemical engineering grad student and work with research in nano catalysis with the oxidation of alcohols. Well...I've been instructed by my research group and in regular class to handle methanol in a fume hood due to it's high toxicity, INHALING the vapours cause blindness and drinking it is lethal in small doses.
    As you may notice putting something on fire warms it up, in other words it gets more excited, thus has more energy to "break" the atmospheric pressure holding it in liquid form, aka MORE VAPOURS.
    And someone said that it's result in combustion is also CO2 + H2O but nature is a bitch and it's never perfect. There is also methanol being spit up into the air you breath. Methanol is highly volatile, so much so that it condensed and cooled water around a beaker of methanol at my lab, btw it was about 27 Celsius (80F)

    I'm a chemical engineering grad student and work with research in nano catalysis with the oxidation of alcohols. Well...I've been instructed by my research group and in regular class to handle methanol in a fume hood due to it's high toxicity, INHALING the vapours cause blindness and drinking it is lethal in small doses.
    As you may notice putting something on fire warms it up, in other words it gets more excited, thus has more energy to "break" the atmospheric pressure holding it in liquid form, aka MORE VAPOURS.
    And someone said that it's result in combustion is also CO2 + H2O, great job reading about complete combustion, but nature is a bitch and it's never perfect. There is also methanol being spit up into the air you breath. Ethanol is hard to find over where u live? Is it worth going to the hospital over it?

    True. That's why I gave the warning in the instructable. I used methanol because it's easier to get than pure ethanol. As I'm not into racing or "illicit" chemistry, I just needed a small amount. It's true that triethyl borate is also flammable, but I haven't tested it yet. I tried to minimize the danger of the methanol by making a very small lamp rather than the "pour it everywhere and light it" method.