How to Make Rainbow Fire and Colored Fire Pinecones

 Rainbow Fire

It's easy to turn an ordinary flame into a rainbow-colored flame. This flame was produced by burning ordinary gel fuel, which is sold for decorative clay fire pots. You can find the pots at just about any home store (e.g., Target, Home Depot, Wal-mart, Lowes). The gel burns at a fairly cool temperature, slowly enough that a small cup maintains a flame for hours. All you need to do to duplicate this effect is sprinkle boric acid onto the gel. You can find boric acid as a roach killer or disinfectant powder. Only a pinch of boric acid is needed. Eventually the gel fuel will be consumed, leaving the boric acid behind. You don't need to add more chemical to the pot to maintain the color, but if you ever want to return to an ordinary flame you'll need to rinse the boric acid away with water before the next use.

How the Rainbow Effect Works

Boric acid doesn't actually burn in the flame. Instead, the heat of combustion ionizes the salt, producing a characteristic green emission. The alcohol of the gel fuel burns blue, edging toward yellow and orange where the flame is cooler. When you put the alcohol-based flame together with the boric acid emission spectrum you get most of the colors of the rainbow.

Other Colors

Boric acid isn't the only salt that colors flames. You could experiment with copper salts (blue to green), strontium (red) or potassium salts (violet). It's best to use a single salt because mixing them together more often produces a yellow flame than a multicolored flame. This is because the brightest emission comes from sodium, which burns yellow and is an extremely common contaminant of many household chemicals

Colored Fire Pinecones

How can you make your fire more festive? Toss on a few colored fire pinecones! Colored fire pinecones are extremely easy to make. All you need is one common household chemical.

Colored Fire Pinecone Materials

• dry pinecones
• boric acid (usually sold as a disinfectant in the pharmacy section of stores)
• alcohol (optional)

Alcohol is not necessary for this project, but it is a good accelerant if you are having trouble getting your pinecones to burn, which is possible if they are still a little green. Also, alcohol burns with a blue flame, so it will add another color to the fire yet won't overpower the other flame colors in your pinecone. Methanol is sold as Heet™ fuel treatment (avoid contact with skin). Isopropyl alcohol (rubbing alcohol) or ethanol (e.g., from rum or vodka) work well, too.

Methods of Preparing Colored Fire Pinecones

Method #1: This is the quick-and-easy method of getting pinecones to burn in colors. Sprinkle a little boric acid powder onto the pinecone. Squirt a small amount of alcohol onto the pinecone. Light the pinecone.

Method #2: Dissolve the boric acid in a small amount of water or alcohol. Soak the pinecones in the colorant solution and allow them to dry.

Boric acid is a good chemical for this project because it's easily obtained, safe, and can give you a full spectrum of flame colors. However, any of the safe colorants for making colored fire can be used to make colored fire pinecones, so don't be afraid to experiment with other chemicals. You can prepare colored pinecones in advance to give as gifts or to burn throughout the season. If you like, you can scent the pinecones by adding a small amount