Despite what you may have learned watching Saturday Morning Cartoons, cannon are not fired by lighting a fuse like you see on a firecracker which slowly burns down to the charge. Well, they are but the fuse is generally a pile of loose gunpowder or a gunpowder impregnated quil that burns very rapidly to fire the cannon. Much the same as the flashpan on a flintlock, 18th Century cannon were fired by external ignition but unlike the flintlock, the ignition source was generally a smoldering cord known as a slow match or match cord.
Slow match or match cord is the very slow burning cord or twine fuse used to ignite the priming charge on a cannon (also historically used by early matchlock musketeers). Slow matches are used because it can be handled roughly handled without going out, and only presents a small glowing tip instead of a large flame that risked unintended ignition of nearby gunpowder. To prevent dragging the match cord on the wet ground, the match cord is often carried on a forked wood or iron support that can be inserted into the ground to hold the end of the match cord. These linstock also provide a small amount reach which protects the artillery crew from the flash when the priming charge is ignited.
Match cord can be purchased from various sutlers for about $5/yard (GG Godwin sells 6 ft shanks for $9.95). By my computations, however, slow match can be made for about $0.81/yard and all that is needed is a large bucket to soak the cord and the materials used. Given that slow match has a typical burn rate of approximately 1 ft/hour, making your own makes really good sense.
The slow match is a length of hemp, cotton, or flax cord that had been chemically treated to make it burn slowly and consistently for an extended period. Essentially, we use the same accelerant, saltpeter, as used in gunpowder but since the fuel is tightly wound cord rather than fine powder of charcoal, slow match burns smoothly and constantly. There are many formulas for match cord, depending on the desired burn rates and cording chosen.
The process is very simple. We start by cutting cotton cord into usable lengths. Then because modern rope or utility cord is often treated with fire retardant chemicals (especially cord used to make clothing or upholstery piping), we soak the cord in lye to break down these chemicals. Once that is done, we soak the cord in saltpeter (Sodium Nitrate or Potassium Nitrate) which helps the cord to burn. The predominant chemical used is potassium nitrate, although sodium nitrate, and lead acetate also appear to have been used. Potassium nitrate, however, has an advantage over sodium nitrate in that it is less likely to absorb moisture from the atmosphere. Finally, we dry the cord.
Materials
- ½” Cotton Cord
- Saltpeter (Spectracide Stump remover)
- Lye (Crystal Lye Drain Cleaner)
Steps:
- Cut the cord into lengths (I chose 6ft lengths). It is possible to make 25 – 30 six foot shanks in a 5 gallon batch of solution.
- Dissolve 2oz of lye in 5 gallons of water. Be careful when handling lye as it is corrosive to skin. Also be aware of the heat released when water and lye are mixed. It is possible to melt a plastic bucket if you add the water too slowly.
- Press the cord until it is fully submerged in the lye solution and all the trapped air is released.
- Leave at least 24 hours but it can sit for a week before the cord begins to degrade.
- Rinse cord in water.
- Dissolve 16 oz of Saltpeter in 5 gallons of water.
- Soak cord in this solution for at least 24 hours but it can soak for several weeks if you get busy and forget.
- Hang to dry.
Michael Carver -- Historical Interpreter/Reenactor 