Composition of Chinese firecrackers

[CatSpit]

Most are familiar with the perchlorate / dark aluminum composition that is used in many salutes, but common Chinese firecrackers have something that is visually different.
Unwinding them I always found a bright silver composition unlike the well known mix I mentioned above. My best guess they use bright flake aluminum but if so, why?

The net has a wealth of information but this question has eluded me for some time.
If someone wants to fill me in, please do.

[countryboy7978]

Bright flake aluminum is cheaper than dark aluminum. Bottom line. The oxidizer is still perchlorate since chlorate is banned by CPSC in consumer items. Sulfur is typically added to boost efficiency since it does compensate for poorer grades of aluminum as well as being ultra inexpensive compared to any grade of aluminum.

[CatSpit]

Thanks countryboy, been wondering about this for a long time.

I wasn’t sure bright flake AL could be used in something as small as 50 mg. I didn’t think it would pack the “punch” that the little crackers have. Makes perfect sense to keep costs low and adding the sulfur to make up for the cheaper aluminum.

[RalphieJ]

Thanks countryboy, been wondering about this for a long time.

I wasn’t sure bright flake AL could be used in something as small as 50 mg. I didn’t think it would pack the “punch” that the little crackers have. Makes perfect sense to keep costs low and adding the sulfur to make up for the cheaper aluminum.

I recall the ICC Class C crackers and even the crimped DOT's that followed having that musky (but not unpleasant) sulfur "aroma", but today's wimpy 50mg's don't seem to have it. Could it be my imagination or has the formula evolved?

[countryboy7978]

I don't think the formulas have evolved, simply because of economics. In order to use 70/30 in a small firecracker and get it to function, it requires good aluminum which is costly for something as low profit as a Chinese firecracker. Even large salute shells use cheap aluminums and sulfur for sure. However I do agree that firecrackers of today have a different smell pre-ignition. You can definitely small the sulfur after they are fired.

[CatSpit]

One might think the quality would evolve but last brick I bought for my Nephew was total garbage.

When I was a kid Thunderbomb brand was all I got. Recently I searched everywhere for that brand and found one place that had them and bought 2 bricks. I wanted to show my Nephew what good firecrackers are… That was a laugh, they don’t even look like what I had when I was a kid, not to mention they only pop, snap or dud. I didn’t find out until later they stopped making that brand. I believe I bought Thunderbomb knock-offs. I still have one brick left.

[countryboy7978]

Thunder Bomb was one of the first firecrackers to come into the country after the US and China restored relations in the early-1970s. The original Thunder Bomb firecrackers had a much heavier load of flash powder at that time (up to 3X what is allowed today). In 1977 the CPSC lowered the powder limit to 50mg. However most firecrackers, including Thunder Bomb continued to load their firecrackers heavier than the allowed amount since the importers were not being checked for compliance. This ended in the late 1980s as CPSC seized containers full of overloaded product including Thunder Bomb. Coupled with simple economics, the manufacturing methods changed to clay/plaster plugs over manually crimping the casings closed. The casings are cheaper paper without the classic shell wraps (stars, snowflakes, flowers, Bomb logos). Fuses got shorter too since the strings are not supposed to be unwound per CPSC. The crackers used to be hand braided but are now braided using a machine which combined with the short fuses makes sloppy strings that fall apart easily. Unwinding firecrackers from a few decades ago took time since most were strung using paper strands instead of thread. What you have left today is a combination of importers requesting a cheaper product since most people will not pay a premium for firecrackers that typically sell for under $10 a brick. The fines/loss of product force importers to err on the side of caution, typically underloading firecrackers and bottle rockets. Sure there are overloaded items still getting in however the risk vs reward is different for a large cake than a low margin item like firecrackers. Sooner or later firecrackers will begin to disappear. They are too much work for so little return. Ladyfingers are almost extinct and many items that incorporated small firecrackers into the effect (i.e., Happy cakes, Roman candles, novelties) have begun to replace firecrackers with dragon egg stars. I hope this cleared some of your questions up.

[CatSpit]

Countryboy I really appreciate taking the time to explain all this. I learned more from your replies than searching the net for months on end and trying to put it all together. Your absolutely right, the ones I have are plain wrapper with a fuse 1/4” to 1/2 “ long and about as loud as a mouse fart.
When I was a kid we didn’t have much money. All the firecrackers we had we unwound and shot them individually. We blew up ant hills, toy cars and such. Lots more fun than shooting the whole pack at once, to us that was wasting good crackers. Rarely you have one to accidentally go off in your fingers, they didn’t have enough power to maim you for life but you sure knew better next time.
I know government wants to protect us and over regulates everything, but consider what kind of people video themselves sticking fireworks up their butt and setting them off. I don’t think firecrackers with short fuses will keep these people from lighting them. I say the government needs to loosen up and let Darwin do his job.

I guess firecrackers as I knew them are gone. Then again just like a cigarette, you want a good one you got to role your own.

[countryboy7978]

The CPSC testing procedure actually automatically passes any firecracker with under 30mg of powder. If the cracker being tested contains over 30mg then a sample size of ten are cut open and weighed (trying not to get any clay into the flash) and an average is taken. If it's over 50mg average powder loss, the batch is failed and usually has to be destroyed. That's why the weak reports. They are underloaded to avoid scrutiny They are not even 50mg. The old DOT Boomer ladyfingers contained slightly over 50mg of very good quality flash powder. Many of these crackers today would be trumped by a little 7/8" cracker of old. There are a few decent ones out and Black Cat is one of them. Trying to find DOT Thunder Bomb firecrackers is getting more difficult and definitely more expensive. If you attend swap meets or conventions you will come across some. Expect the pay at least what you would expect to pay for a NOAB/9 shot plate for one brick of DOT Thunder Bomb. Older versions command well over $100 for an 80/16. For a nice treat, they are worth it.