The classic BIG BANG "carbide" cannon from the early 1900s makes a good
bang quickly, easily and safely.  Calcium carbide creates acetylene when
dropped into water.  But results with the cannnon varied a lot.  Exactly 10
percent of acetylene must mix with 90 percent of air for the loudest bang. If
that ratio is not exact, the Bangsite got too white or the timing was off and
more air got in, the bang was weaker.
  The reaction of calcium carbide and water produces acetylene and lime. When
8.7 grains of Bangsite was put into 1 ounce of water the reaction time was
about 4 seconds and the temperature went up 12 degrees F.  The volume of
acetylene generated was about 13 cu. in.  (1 gram = 15.43 grains)
                      THE PRINGLES CAN CANNON
  A very simple, cheap cannon uses a Pringles can.  The can has an inside
diameter of 2 & 7/8" and a depth of 9 & 5/8" for a volume of 62.6 cu. in.
So 6.26 cu. in. of acetylene needs to be produced by 4.2 grains of Bangsite.
                            GET READY
  Have a 4" x 4" square of heavy, flat cardboard, 2" x 2" square of tissue,
a 1-ounce pill cup or jigger of water and 4" of fuse ready.
The PRINGLES CAN CANNON, equipment and supplies.
  Fuse can be found at fireworks stores.  Bangsite can be ordered online.
                          PREPARE TO FIRE
NOTE: Once you start this you MUST do all the steps to the end.
  1. Poke a hole in the side of the cannon about in the middle for the fuse.
  2. Using a reloader's balance scale, measure out 4.2 grains of Bangsite
                                                   and pinch it in the tissue.
The Smart Weigh JDS20.
  1. Put 3" to 4" of fuse in the Pringles can.
  2. Using a digital scale, put the tissue on the pan, turn the scale on and
     wait for the zeros.
  3. Trickle 4.2 grains or .272 grams of Bangsite onto the tissue and then
     pinch the tissue over the Bangsite.
  4. Put the cap back on the tube immediately!
  5. Pour the ounce of water in down the side opposite the fuse.
  6. Drop the Bangsite pouch in.
  7. Put the cardboard on top
  8. Light the fuse
  The fuse delay will allow all the carbide to react with the water.  The
acetylene will push 10% of air out for the right air/acetylene mix.
  The cardboard square can be seen on top of the fireball.
 1.  Get the volume in ounces by filling the container with water.
 2.  Pour the water into a measuring cup as many times as necessary.
 3.  Add up all the ounces.
 4.  Multiply the total ounces by 1.8 to get cubic inches.
 5.  The acetylene must be 1/10 of the total volume, so move the decimal
                                                  point one place to the left.
 6.  The amount of Bangsite in grains is the volume from step 5 times .67.
  (To convert the amount of Bangsite in grains to grams, divide by 15.43.)
   The amount of Bangsite used makes a difference in the sound and the flash.
Here are some tests of different amounts.  But the images are from one video
frame and that frame may not have caught the biggest flame.
Using different amounts of Bangsite:
This was 4.2 grains.
This was 6.2 grains.
This was 6.4 grains.
   The flame seems to vary considerably.
   If instead of acetylene and air you mix acetylene and pure oxygen and
ignite it that will create the loudest and sharpest bang.
Everything needed to make the bombs.
   The clear plastic bomb bottle needs to have a dividing line marked on it.
The only item that had to be ordered is calcium carbide.  Most any bottle can
be used for the acetylene generator.  Drill a hole in the cap for the aquarium
store tubing to fit tightly.  A scratch awl is needed to poke a hole in the
bomb bottle for fireworks-store fuse.
   Put the oxygen regulator on the oxygen bottle.  It screws on "backwards".
Fill the bucket with water.  Put water in the acetylene generator with about
half a cup of air.  Put the tubing into the hole in the cap.
   Put water into the bomb bottle such that rightside up or upside down the
water level is the same and mark that level.  (Ideally there should be 6 units
of oxygen to 5 units of acetylene.)
   Fill the bomb bottle with water and put it upside down into the bucket of
water.  Put the tubing in the acetylene generator cap and put the other end in
the bucket of water, but not in the bomb bottle.
The bucket, acetylene generator and bomb bottle.
    Have someone hold the bomb bottle in the bucket.  For a Safe and Sane size
bomb bottle drop a rounded half-teaspoon of carbide chunks into the acetylene
generator and quickly screw the cap on. Let the air in the generator and the
tubing get pushed out as bubbles first, then put the tubing up into the bomb
bottle a few inches and let the acetylene go in.
   When the bomb bottle water level reaches the line, pinch the tubing and
pull it out of the cap.
IMPORTANT: Have someone move the acetylene generator out of the work area!
Adding the oxygen.
   Put the tubing on the torch nozzle and open the oxygen regulator.  When the
bubbles start coming out of the bottom, shut the oxygen off.
   Take the tubing out of the bomb bottle and out of the bucket.  Put the cap
on the bomb bottle while it's under water and then take it out of the bucket.
   When ready, poke a hole in the bomb bottle for the fuse with the scratch
awl and put the fuse in.  It is now ready.
The A-Bomb blast.
   The gases were at 85 degrees F.  The white-hot explosion is at 5,720
degrees F!  The blast is unlike any fireworks report you've ever heard!
Official bomb bottle sizes.
   Safe and Sane, Hearing car alarms, Hearing sirens, Court hearing.