How to Make Roman Candles
The principle on which the Roman candle is constructed is as follows. At the bottom of the case is a plug of clay. On the top of this is a small amount of 4Fg rifle powder. On top of this powder is a pierced, cylindrical star, which just comfortably slides down the tube. Surrounding and on top of the star is a slow-burning powder called "candle comp." The grain powder, star, and candle comp sequence is repeated until the tube is filled.
The comp burns like a fountain with luminous sparks. Upon reaching the star, the comp ignites it and flashes around it and through its cavity to fire the blowing (propelling) charge of grain powder. The blowing charge also ignites the next layer of candle comp., and the effect is repeated.
The fit of the stars in the tube must be just right. If the stars are too loose, they will merely pop out of the top and land on the ground burning; too tight, they will be shot out with such force that they will blow themselves out. The candle comp. must fit snugly around the stars and must also be firmly rammed down on top of them, otherwise the stars will come out like machine gun bullets. The amount of grain powder varies with the position of the star, smaller amounts being used at the lower portion of the case. This is done so the stars may rise to approximately the same height: The charge at the bottom acts through a greater distance and on a firmer surface, so it naturally acts more effectively and less is required.
- 10 parts Potassium Nitrate
- 2 parts Sulfur
- 4 parts Charcoal, 100 mesh
- 1 part Charcoal, 40 mesh
- 1 part Charcoal, 12-20 mesh
- 6 parts Potassium Perchlorate
- 3 parts Aluminum, bright
- 1 part Aluminum, flitters
- 1 part Red Gum Yacca
We recommend using the ¾" ID (internal diameter) tubes from Hobby Horse. These are available with walls either ⅛" or 3⁄16" thick. You can use the thinner (and cheaper) tubes if you're careful, but some of our customers say they have had trouble with the thin wall tubes burning through the sides. If you're not sure, we suggest you experiment with both sizes and see which works best.
The ¾" ID Hobby Horse tubes are slightly over 30" long and can be cut to make four 7½" or two 15" candles.
- Black match for hole in star to transfer fire to lift charge.
- 4Fg black (lift) rifle powder
- Dry, powdered clay
To make a 15" Roman Candle, you'll need the following tools:
- 15" Roman Candle Rammer with ¾" ID (Stock #255-34)
- 15" Roman Candle Star Pump with ¾" ID and 11⁄16" outer diameter (Stock #213-1116)
- Adjustable Powder Scoop (either #143-12 or #143-34)
- Rawhide or non-ferrous hammer (If you don't have a hammer, you can get one here.)
- Standard scoop (A good source for scoops is a sports store that sells reloading supplies.)
The rammer is a rod slightly thinner than the ID so it can pass easily up and down in the candle case.
The adjustable powder scoop is like a ¼" diameter regular scoop, except that the handle is allowed to slide within the shovel part of the scoop. Thus, each powder charge can be easily adjusted using only one scoop.
The Roman Candle Star Pump is adapted for making Roman candle stars. The plunger has in its center a rod that is ⅙ the diameter and equal in length to the star it makes. Thus, it forms a central cavity down the center of the star.
A regular scoop is used for measuring the charges of candle comp and clay.
This might be a good time to give a friendly reminder: If you use kitchen utensils for handling toxic chemicals, please don't use them with food.
Place the case on a firm foundation, pour in a scoopful of clay and ram very hard, using a rawhide mallet. Remove the rammer and pour in a scoop of gun powder. (Note: the exact amount must be ascertained by experimentation. Adjust the powder scoop so it increases the powder charge for each star. All stars should be blown to the same height—the higher the better. However, if too much powder is used the stars will be shot out with so much force that the flame will be extinguished and they will be "blown blind." Start with about 2–3 grains for the first charge.)
On top of the powder charge, drop in a star (which has been primed with a piece of black match down the center hole), and then a scoopful of candle comp. Ram with about six light blows of the mallet. Remove the rammer and pour in another scoop of gun powder, another star and another scoop of candle comp. Ram as before and repeat until the case has the desired number of stars. Prime, match and nose, and the candle is finished.