Safety Fuse
PRIMING

 

Sometimes visco (safety) fuse can be somewhat difficult to ignite, especially  in the middle of a show when you're trying to do so quickly.  Below you'll find two methods of priming - that is, adding a special coating to the end of the fuse to make it catch fire more easily.


METHOD 1

You will need the following materials

-black powder
-dextrin

PROCEDURE

All you need to do here is make a thick liquid solution of black powder.  Add just enough hot water to a couple tablespoons of black powder until you get a thick slurry with the consistency of soup.  Put in just a small pinch of dextrin (yeah, I'm starting to sound like a chef) so the substance will be able to stick.

Take the piece of visco fuse you wish to prime - this could be the leader fuse to a longer piece of quick match, or even just the fuse from a consumer firework.  Use pliers/scissors to cut the fuse at an angle to expose the powder core, and dip it about a centimeter of it into the hot black powder solution you just made.  If this is too awkward, you can try using a small dowel or pencil to apply to goop the the fuse.  Carefully move the newly primed fuse to a sunny location, and let it dry for at least a day - you want to be sure that all moisture has evaporated.  When it's all dry, you'll have a hard, dark, crystalline blob on the end of the fuse that will ignite much easier and faster than the fuse by itself.

 

METHOD 2

You will need the following materials

-acetone
-ping pong balls
-black powder

PROCEDURE

Find a small container that can be used for mixing.  I find that those little orange medication bottles work good.  Fill it up about 1/2-3/4 full of acetone.  Take two ping pong balls and cut them into small chunks using a knife or scissors.  Dump the chunks into the container of acetone, and use a small stirring stick to make sure all of the pieces are submerged.  Put the cap on and let it sit for several minutes.  Ping pong balls are made of nitrocellulose, a highly flammable organic compound (try lighting one on fire).  Dissolving them in acetone creates a type of nitrocellulose lacquer, which is binder commonly used in pyrotechnics.

Take the cap off the bottle.  You should have a gooey, slightly yellowish liquid.  If there are still chunks of ping pong ball floating around, stir the substance until they dissolve.  It should be a little bit thinner than white glue.  If it's too thick, add more acetone.  If it's too thin, add more ping pong ball chunks.  Once it's the right consistency, add several teaspoons/grams (it really doesn't matter) of fine black powder - I use FFFFg - to the liquid, or however much it takes to make it black.

To prime your fuses, stick a small dowel or pen into the prime.  It will be quite sticky.  Take it out, and simply smear the goop onto the first centimeter or so of fuse.  The stuff can be pretty stringy as well, so you may have to wrap the little dangling pieces around the fuse with the pen to keep them from dripping everywhere, kind of like those taffy machines.  I love taffy.  Don't use too much - once the stuff hardens, it will brn quite suddenly, often with a 'pop'.

Put it out in the sun to dry.  The acetone will quickly evaporate, allowing the nitrocellulose to harden, which makes the stuff ready to fire in about half a day.  Just like in method 1, the primer will easily take fire and ignite the fuse.



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