How to Make a Rainbow Fire Jack O’Lantern

| October 1, 2013 | 0 Comments

Bored of always making the same Halloween decorations? Can’t think of anything else to do with your Jack O’Lantern? Tried every scary face carving you can imagine? When a simple Halloween Jack O’Lantern won’t do, follow these instructions for how to make a Rainbow fire Jack O’Lantern. This spectacular display will more than impress your friends as your pumpkin burns with rainbow colored flames.

This fantastic video was created by Anne Marie Helmenstine PhD, author and former chemistry teacher, who loves to demonstrate the wonders of science in fun and exciting ways. Using just basic household materials you too can create a rainbow fire Jack O’Lantern that is truly amazing.

The science is simple: when chemicals burn, they emit different colored flames, depending on which elements they contains. When boric acid is heated, it produces a green flame. The methanol found in the hand sanitizer gives off a blue flame, and the chemicals found in the pumpkin itself, namely Sodium, burn to give off a yellow flame. An orangey flame is also produced from the light shining through the orange flesh of the pumpkin. When all of these colors combine on the surface and inside the pumpkin they create a wonderful display of multicolored rainbow fire.

Before you start creating a Rainbow Fire Halloween Jack-o-Lantern please read this safety advice. Adult supervision is essential as strong chemicals and flames require proper handling. Young children will also need supervision whilst carving the face onto the Halloween Jack O’Lantern. As with all projects using fire, this should be carried out in a well-ventilated area, away from any flammable materials. The Jack O’Lantern should be placed on a heat resistant surface and spectators should stand well back. It is advisable to use a taper or candle when lighting the lantern as the chemicals ignite very quickly, and the person lighting it should be as far back as possible. A fire extinguisher or bucket of water should be on hand in case of accidents, and the flaming Jack O’Lantern should never be left alone.

Materials List:

A curved pumpkin
1 Bottle of ethanol (hand sanitizer)
Pure boric acid (roach killer)
Methanol (Heet fuel treatment)


1. Start

Place your already carved pumpkin on a heat resistant surface. You can do this in the kitchen but keep it away from food preparation areas if possible. It shouldn’t set off fire alarms as the flames do not make much smoke.

2. Add boric acid

Sprinkle a generous amount of boric acid (roach killer) inside the Jack O’Lantern. This will create the green flames.

3. Add methanol

Tip a good glug of methanol inside the pumpkin. This will create the blue flames.

The yellow flames will be created by the sodium within the pumpkin itself.

4. Apply the sanitizer

To keep the colored flames burning on the surface of the pumpkin, rub the pumpkin skin liberally with hand sanitizer.

5. Add more boric acid

Sprinkle the outer surface of the pumpkin with the boric acid to make sure that the colours cover it too.

6. Light it

Set your Jack O’Lantern on fire, standing well back, making sure that it is placed on a suitable surface beforehand.

Watch the amazing colours burn as the chemicals combine.

To keep the flaming pumpkin burning for longer, you will need to add more alcohol, but it should burn for several minutes even without the extra.

Once the pumpkin has stopped burning, it doesn’t have to be thrown out straight away. The colors are created by the chemicals burning, rather than the flesh of the pumpkin. It probably won’t last as long as a normal Halloween Jack O’Lantern, but then this is no ordinary Jack O’Lantern.

So how about making a Jack-o-Lantern with rainbow fire this Halloween? It would be a great addition to any Halloween party, bonfire or post-trick or treating celebration.

Please always remember to follow the safety instructions to prevent any accidents. Let your imagination run wild with the faces you carve for your flaming Jack o lantern, then stand back and watch in amazement as it burns in rainbow fire!

Have a wonderful, rainbow-colored Halloween!

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