Recap of the Story Thus Far, Lessons Learned
Entry posted by jwitt
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Here's a really long entry chronicling my entry into pyrotechnics and aerial shell building. It's cobbled together from several entries I've made leading up to actual shell production. They aren't necessary anymore, but I'm preserving this for posterity.
#1 - Intro
I figured I'd make a blog to document my progress from deciding to dabble in pyrotechnics all the way through hand firing a display sometime around the 4th. Maybe it will be a good reference for someone in the same position in the future, maybe I'll pick up some advise, or maybe it will just be a fun thing to do. We shall see...
Background:
After a few months of research, my roommate and I plunked down some money and set ourselves up with most of what we need to begin production of BP and several charcoal and color stars, with plans to ultimately pack the stuff into 3" paper ball shells.
Already had: scale, KCLO4, dark Al (kindly given to me by a buddy who realized that's not the sort of thing to casually mess with)
Mail order packages began to roll in. Lots of KNO3, Sodium Benzoate for whistle booster, metal powders, parlon, coloring agents, a couple hundred feet of visco, fast paper fuse, 3" mortars, a mile of 3/4" gummed tape, 100 3" hemis, 1/4" x 1/5" tubes, ball mill, media, and "much much more."
#2- Planning
Planning is critical to mission success. Duh.
Here's my original plan. Things as of the end of May are progressing more or less along this plan.
The Plan, in general:
- Research. Organize everything in Microsoft OneNote- an awesome program for gathering research notes!
- Gather materials.
- Develop production schedule
- Make stuff and test prototype shells
- Hand fire 3" shells
Shell Components:
- Shells: paper hemis, 3"
- Stars: Charcoal streamer of some sort(s), D1, Granite, and Veline color
- Extras: Falling leaves and flying fish fuse. Maybe some sort of inserts too if I have the time?
- Burst: BP coated rice hulls with whistle booster (dusted onto burst charge)
- Lift: Riced red gum bound BP made with Alder charcoal
- Fusing: american visco > leader (paper fuse in match pipe) > lift > 1/4" chinese time fuse (crossmatched or primed on outside, crossmatched on inside)
Shell Designs:
To be determined- color pistils, granulated glitter mixed with burst in non-glitter shells, etc.
Shell Quality Assessment Plan:
- number each shell, print out firing order
- record video of display for reference
- interested parties in audience give general opinions as desired
- perform cost/coolness analysis as well as "general feel" of show - mix of shells, firing order/combinations in salvos, etc
#3- Progress
Progress and plans, Apr-May. After some managerial hiccups, things are falling into place! Ball mill, grinding media, paper products, and 10 3" HDPE guns are on my doorstep as well as 20 pounds of Alder charcoal.
Total stars made so far:
- 2lb zinc pearl
- 1lb Chrys #6 +7% Ti
- 1lb TT +1% lampblack
- 2lb "Long Hangtime Willow" lampblack star
That was an easy week of "research production" ran concurrently with gardening (and having to stop midweek to clean everything up for a small party)
1 pound batches of streamer stars are an appropriate "sweet spot" for small scale home production- not too much to handle myself, and a helper makes things easier. Mix fits in convenient containers, etc etc. Perfect. I can also make LOTS of variations of charcoal streamers to help dial in my favorite effects in the future.
2 pound batches aren't bad to make either, but it's a bit of a long session for weekday evenings after work.
I've more or less figured out wetting and cutting comps- getting real nice consistency and perfecting cutting/breaking up/priming methods. It's really easy to get a nice prime layer on the stars, and I'm screening the excess prime off and recycling it for other charcoal streamer stars.
In other news- went out to the shoot site yesterday and paced off the 200' setback. (Well, my pace count is 73 paces for 100m, so I came close). Also shot some clay targets and did some long-range .22 shooting on a perfect spring day. The wind really blew those .22s around, but even with cheap ammo, a heavy barrel Remington Matchmaster with Redfield sights is pretty darn accurate at ~175m prone unsupported- got to practice my dubious Kentucky windage skills.
Stars to be made in the immediate future:
- Spider suggested to me by Mumbles
- Chrys 8
- Chrys of mystery...I mean, why not- it's mysterious!
- Veline Blue and Ruby Red.
- Something white and metallic.
- D1 Glitter
#4- LESSONS LEARNED
In General:
- Mail order. Try to make only 2 chemical orders. Metal powders in one order and oxidizers, carbonates, other fuels and binders, and fuse in the second. Skylighter has stricter shipping policies than many companies, so a large order from them might be 3 boxes.
- Planning. Plan what you need early and double-check the list over a period of a couple weeks. Calculate needs to the best of your ability. This will help save you shipping costs. Go ahead to the hardware store for containers, paper, PPE, solvents, dowels, adhesives, string, and other odds and ends while your order is in transit.
- Self-Sufficiency. As you progress, learn to make things yourself. Blackmatch, match pipes, spolettes, charcoal, mill jars, and maybe even hemispheres. All of these skills, while seemingly overwhelming, are really simple. You'll naturally progress through the learning process a little bit at a time as you concentrate on the greater goal of shell building.
- Workshop time. Schedule uninterrupted, leisurely workshop time. Concentration and slow progress are required. Maintain a clean shop- use painter's paper to make cleanup a snap. Burn pyro trash at the end of the session, far away from your workplace.
- Safety. Read and re-read several good safety essays on a regular basis during your work season. Hammer that information into your head!
- Testing. Make good notes and test one device before making the next. Make slow, deliberate changes as to not introduce too many variables at once.
BP:
- BP components must be dry, or else the mixture will clump before it is sufficiently milled. Dry charcoal and KNO3 in a warm oven for about 30 minutes...separately...duh.
- 1kg is probably a slight over-load for a 6" PVC mill jar containing 10 pounds of ceramic grinding media. (Milled in a safe location!!!)
- I know my BP is "about done milling" when a burn test leaves little ash and no visible KNO3 slag. The milling time is roughly 8 hours for a 1kg load in my setup.
- Red gum bound BP grains are crumbly, but hard enough to withstand handling and storage.
- Ricing through 10 mesh gives you a majority of 4FA equivalent (retained on 20 mesh), which works to lift 3" shells.
Rice Hulls:
- Per Dagabu's suggestion, I made rice hulls in a 6:1 ratio of BP to dry hulls.
- Hulls soaked for 20 minutes in warm water, spun overhead in a screen bag to shake off excess water.
- 5% dextrin is then added to 4/5 of the mill dust. The last increment is applied to "finish" the grains.
- A very slight amount of water can be sprayed onto the hulls as needed to help the powder stick, this is seldom necessary.
- Allow to dry for 1 week. Resulting hulls, when burned, will burn very quickly and energetically. Rice hulls will not smolder at all when dry, it's over in an instant.
Shell Building:
- 2-3 grams of whistle mix booster is a nice addition to a 3" shell with decent quality BP coated hulls.
- 1/4" charcoal stars are plenty big, unless they're very fast burning like Chrys #6.
- I found that 5 turns of the 3-strip method is a good place to start for 3" shells. Final dimensions can be tweaked by how much overlap you use in the pattern.
- A masking tape flag protects the time fuse and gives you a place to record shell information.
- Burnishing a shell every couple layers results in a smoother, rounder, harder shell. Burnishing layers 2, 4, and 5 is my current method, with less than 1 minute's burnishing on layers 1 and 3.
- A string loop is quick and easy to install.
Thanks to all you guys for helping me progress from research to really well-executed quality shells so quickly! I somehow skipped "ragged breaks and blind stars" and went right into awesome pretty stuff way up in the air. I know I didn't credit your suggestions here, but the proof is in the pudding...or rather...in the sky. I hope to be able to repay this fine community in some way in the near future!
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