Making 30 3" Paper Ball Shells in 3 Weeks
Entry posted by jwitt
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I'm writing this blog entry because I'd like to share my techniques and findings. I think it will be a nice introductory tutorial to those who are considering making paper ball shells.
Starting my second big shell building project got me thinking about efficiency. I wanted to get these shells built in the minimum time possible, while still being as safe as possible. Of course, it is safer to build one shell at a time- the total amount of pyrotechnic compositions on the bench at one time is a lot less with 1 shell than 10, 20, or 30. As such, I did some processes all at once, and others (like loading the shells) in batches, building one type of shell at a time. I felt this struck a balance between safety and efficiency.
First, I looked at the stuff I had on hand and what I needed to make.
Supplies on hand:
- 2 kg BP mill dust
- Tub of mill dust used only for spolettes
- Some BP coated rice hulls, looked to be enough to finish 30 shells
- Paper products and fuse
- Stars (Chrys 6 + Ti, Tiger Tail, Zn Pearl)
- Plenty of pyro chemicals
Needed to make:
- Spolettes
- Color & White stars
- Whistle Mix for burst booster
- Lift cups
- Granulated lift
- Fencepost and BP Prime
- Mortar rack
Didn't sound like too much work, aside from assembling the shells.
PRE-ASSEMBLY
I figured the first thing I should do is prepare everything.
- Night 1 - Mixed Fencepost Prime, BP Prime, Ruby Red, Veline Blue, and Skylighter Rubber White star comps
- Night 2 - Granulated BP with red gum/alcohol
- Night 3 - Cut red, white, and blue stars
- Night 4 - Mixed ~150g Whistle Mix
- Night 5 - Sat down with roommate who would design mortar rack and templates for kraft paper lift cup pieces
SPOLETTES
Next, I needed something to stick in those shell hemis.
First, I made oak dowel rammers that fit snugly into 1/4" ID spolette tubes. Design is critical- especially the tip and taper- it's hard to keep from binding the dowel in the tube. Measured and drew lines to help guide the ramming process. A light wax coating seemed to help.
After that, it was a simple matter to ram the correct amounts of powder into the tube with a rubber-faced mallet. The tricky part is filling the tube- a funnel that small just doesn't work well. The first increment is loaded with the dowel inserted. This one is "super-duper-pounded" to make sure the end of the spolette is as tough is it can be.
I got the process to where a couple partial scoops would make a nice increment to ram. It's important to ram spolettes in increments to make sure the powder is consolidated well.
Next, the hemispheres needed to be fused. I taped over the existing fuse holes, preferring to drill my own in the center of the hemi.
...all ready for blackmatch pieces!!!
SHELL ASSEMBLY
To balance efficiency and safety, I laid out hemisphere sets for all of each type of shell I was going to make. That is, I made 6 Tiger Tail shells, so I put out 6 hemi sets. Then:
- Put black match in each spolette tube for passfire
- Load each hemi with a scoop of stars
- Go down the line arranging stars in the hemis
- Grab the rice hull bucket, go down the line filling hemis, then stash the rice hulls
- Grab the Whistle tub, go down the line dolling out the booster charge, stash the whistle tub
- Assemble each shell and have assistant help tape them together
- Tag the spolette end with tape to protect it and label the shell
- Put completed shells in airtight ammo box for storage until pasting
- Repeat with the next batch. Stash leftover stars, bring out new ones.
I found this to be a very efficient method. I didn't record time, but 30-some odd shells (35? Not sure) took at most 4 hours to assemble. Probably more like 2 1/2. (Keep in mind they were already fused- that process took an hour or so)
PASTING
This was the part that worried me. 5 turns of 3-strip method on each shell!??!?!
I used gummed tape, 3/4". I stacked 7 rolls of tape on the table. By pulling and rotating the stack of rolls, one can bring the tape together in one neat stack, and cut strips with shears. A huge amount of strips can be cut this way in 10 minutes!
Each shell took about 75 minutes, including strip cutting and a short break between each shell. Shells were burnished for no more than 1 minute on layers 1, 2, and 4. Shells were burnished for no more than 2 minutes on layers 3 and 5.
PRIMING, FUSING, FINISHING
A buddy got bored and grabbed the sharpies to "help me with color-coding." It sure wasn't much help, using red light while firing shells, and...uh...he didn't do all of 'em. A couple pictured below were lumpy shells done when we were experimenting with time-saving pasting methods- no burnishing, no smoothing out strips. Didn't save much time and made sloppy shells. Also, we don't smoke in the house. 
Uhoh, one day before shooting!!!
I had my trusty assistants doing lift cups and cutting leader fuses the previous day, while I was finishing up pasting and cutting visco.
I stripped lengths of fast firecracker fuse to harvest black match. I cut short lengths to prime the ends of my spolettes. These were hot glued on (gun unplugged and plugged back in by assistant). After that dried, a twine clove hitch was tied around the spolette tube and match ends, and secured with a dab of hot glue.
Then, I weighed out all the lift charges 10 at a time, once again compromising between safety and efficiency. We grabbed the pre-cut leader fuses to which visco had already been attached. We skipped match pipe, because we just didn't have time to make it.
Fuse was taped to the shell, leaving the exposed match ends dangling right by the primed spolette. An additional piece of tape stuck the fuse to the top of the shell. The lift cup was then taped onto the shell with masking tape.
Shells were then loaded into .50 cal cans in the order they were to be shot. The finale shells were timed with different lengths of visco and numbered. The others were just grouped so there was a nice variety for hand-firing. Ammo cans kept moisture and pesky little sparks off the shells.
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