
Make cool Halloween jack o lanterns that glow in the dark, shoot flames, feature smoke or colored fire, or have other special effects. Take your pumpkin to the next level with one of these jack o lantern ideas.
Rainbow Flames Jack o Lantern
All you need for the rainbow flames jack o lantern is a carved Halloween pumpkin and some hand sanitizer. Coat the inside and outside of the pumpkin with the gel and ignite it. The alcohol in hand sanitizer burns blue, but the pumpkin contains salt and various minerals that add color effects. For even more colors, sprinkle a bit of borax onto the gel.
Flame Thrower Jack o Lantern
The flame thrower jack o lantern is the most dramatic Halloween pumpkin. The towering flames come from a roll of toilet paper soaked in kerosene. Flame height ranges from a couple of feet to up to 10 feet. Add borax, boric acid, or copper sulfate for rainbow colors. The flames last between half an hour and two hours, depending on how much toilet paper fits inside your pumpkin.
Self-Carving Pumpkin
The self-carving pumpkin is a popular Halloween chemistry demonstration. The reaction between calcium carbide (CaC2) and water (H2O) makes flammable acetylene gas (C2H2).
CaC2(s) + 2H2O(l) → Ca(OH)2(aq) + C2H2(g)
Igniting the acetylene creates a pressure wave that forces out the pieces of a carefully pre-carved pumpkin, making it appear the pumpkin carves itself.
A safer, albeit less exciting reaction between baking soda and vinegar achieves the same effect and doe not involve any flames. For this version, pre-carve the pumpkin, reassemble it, pour in some baking soda and vinegar, and seal it up. The carbon dioxide gas forces out the carved pieces.
Green Fire Jack o Lantern
Green fire is the easiest cool color effect because all you do is dust the pumpkin with borax or boric acid. You’ll get the most vivid green color using alcohol or hand sanitizer as the fuel, but the chemical colors normal candle flames, too.
Dry Ice Fog Jack o Lantern
Carve a Halloween jack o lantern and add a few chunks of dry ice. Make the pumpkin spew out clouds of fog by adding a bit of warm water. The effect lasts several minutes to a few hours, depending on how much dry ice you use. Warm water makes the most fog, while cooler water makes a longer-lasting fog.
Illuminate a dry ice jack o lantern using a battery-operated light or a glow stick rather than a candle. Dry ice is carbon dioxide, so it’s a natural fire extinguisher.
Bubbles and Lights Jack o Lantern
Add bubble solution to the mixture of dry ice and water and make the Halloween jack o lantern foam at the mouth. Get the best effect by lighting the interior with glow sticks or else a battery-powered light sealed in plastic.
Glow in the Dark Halloween Pumpkin
There’s no carving for the glow in the dark pumpkin, so this Halloween jack o lantern lasts all month. You don’t even need a real pumpkin. Cover a jack o lantern face using tape. Paint the entire pumpkin with glow-in-the-dark paint or glue. After the paint dries, remove the tape. The entire pumpkin glows, except the face. The advantage of using glowing glue is that the pumpkin looks normal until the lights go out. You do need to charge the glow with a bright light to get the best effect. Depending on the product you use, the glow lasts between a few minutes to several hours.
Smoke Bomb Jack o Lantern
Place a smoke bomb inside a jack o lantern for a pumpkin that breathes smoke. Depending on the smoke bomb, it may also breathe fire. The effect lasts as long as the smoke bomb, so it’s highly variable. But, expect to see smoke for between 30 seconds and several minutes.
Red Fire Jack o Lantern
The red fire jack o lantern uses an ordinary carved pumpkin. The red flames come from strontium nitrate. The easiest source of this chemical is a red emergency flare. However, you can use red sparklers just as easily. If you only use a flare or sparkler, the effect lasts as long as your device. But, the strontium salt remains effective. Keep the flames red by including additional fuel. One option is adding a toilet paper roll inside the pumpkin. For a safer version, include a tea light or other small candle.
Black Flames Jack o Lantern
All you need is a normal carved pumpkin and any ordinary fire for the black flames jack o lantern. The flames turn black from the emission and absorption of the yellow line for sodium. So, you spritz the fire with a bit of salt water and shine a low pressure sodium lamp on the flames. Canceling out the light makes it black. Pretty cool, right?
Water Fog Jack o Lantern
Instead of dry ice or smoke, opt for a cleaner form of fog. The water fog jack o lantern uses a water misting device. Usually, these come as tabletop water fountains. Keep in mind, you either need a small dish of water or else enough space in the bottom of the pumpkin for the water and the mister. Light the pumpkin using glow sticks or LED lights enclosed in a seal plastic bag.
Fire Breathing Dragon Pumpkin
Carve a pumpkin so it has a dragon face. Make the dragon jack o lantern breath smoke and fire using red sparkler or else a red emergency flare. Or, apply a bit of chemistry and add either a strontium or lithium salt to get red or pink flames, respectively.