Senko Hanabi – Japanese Sparklers

The delicate and subtle Senko Hanabi sparklers were introduced to me Tom DeWille, the founder of Luna Tech in Alabygodbama. Later I had occasion to visit Tom at the Luna Tech plant, and spent a couple of enjoyable days there learning how they make stage and theatrical fireworks from him. Tom has always been very generous with information and withheld nothing when I asked about various techniques and formulas. (Did you know that you can make a 5/8″ glitter mine using micro stars only-with no lift powder? Write me, I’ll tell you how. Write Ned, he might even make an article out of it!)

While we were puttering around Luna Tech’s lab at 0-dark:30 one night Tom pulled out what looked like incense sticks and lit one. The thing morphed into the most unbelievably pretty sparkler I had ever laid my eyeballs on.

“Senko Hanabi,” Tom chortled. “Got ‘em in Japan 20 years ago.”

He souvenired me one pack of them, and I rationed ‘em out to myself at the rate of about one a year, until…

Until I saw these teeny, leetle, twisty, colored paper things that Fred Olsen was selling at a PGI Convention several years later.

Holding one in my hand, quizzical expression on my face.

“Senko Hanabi,” Fred chortled. “Got ‘em specially made in China. Nobody else has got ‘em. Here, take one outside and light it.” Which I did. Very different looking on the outside from the incense-stick jobbies DeWille had given me, but performed very similar.

I came back inside and promptly tried to buy all he had.

“Nope. Haven’t got enough of them. Need to ration ‘em out. Dunno when I can get any more of them out of China,” replied Fred.

I bought as many as he would spare, and spent the next 7 years rationing them out to friends and family. And when they lit them, always the same “oohs” and “aahhs.”

But Fred didn’t have any more. I asked every Chinese-connected human bean I knew about getting Senko Hanabis. I met either a blank stare on the phone, or a flat “nope.”

When I first went to China a few years back, I bought Skylighter’s initial container of fireworks directly from the factories owned by Shogun. Shogun’s a really great company. Good people, good product. And they were very helpful to me, a newbie at the game, particularly Joe Wan, one of the company’s owners, and John Werner, their US based product designer.

One day we found ourselves at a factory which makes Morning Glory sparklers, and were poking around the ubiquitous fireworks factory sample shelves-where they display every firework they have ever made for anybody, in any country, in every language, at any time since the last dinosaur croaked.

Lo and behold, there, back behind some 7-inch long firecrackers, was a little bundle of Fred Olsen’s twisty paper style Senkos!

Feigning indifference, I blurted “Quick, ask him if he can make these,” to our translator.

The factory manager called a minion into his office, held a single Senko Hanabi sparkler up, and the guy took off at a trot somewhere. 15 Chinese minutes later he’s back holding a small bundle of freshly made Senko Hanabis in front of my dollar encrusted eyeballs, now blinking rapidly to try and reduce the shine in them.

Outside, they burned and sparkled perfectly. The golden, molten globule forming, shrinking, vibrating, and then finally exploding into the most fabulous sparkler spray of all sparklers! Bingo!

But my visions of retiring on Senko Hanabis were quickly quashed. “Nope. Cain’t make ‘em,” he said in perfect Caintonese.

“Too much trouble. Takes too much time. Too much labor. Too expensive to make now.”

“How expensive?” retorts I (I’m an American, for God’s sake. Money is no object.)

“I dunno. I’ll have my guy get back to your guy on it,” he says.

Well, more than 5 years later, his guy has never gotten back to my guy.

Jump to November 2007. Back in China, this time with my Ace Fireworks Finder, Matt Palaszynski.

For the past 3 years, Matt has known about my quest for the Holy Senko. Now, he has finally found a factory that used to make them. But they have not made them for years (there must be a reason). And he doesn’t know if they’re willing to do it again. We are scheduled to meet the factory owner this morning to see.

We drive through one of the rat-mazes of little, windey, one-lane concrete roads outside Liuyang, me and Anne, with Annie the translator, and Matt. Much cell-phone back-and-forthing, the factory owner homing us in on his office.

We all arrive at his office at about the same time, him on his motorcycle, us in the car. Handshakes all around, the obligatory offering and declines of his cigarettes. Then we get down to bidness.

He fumbles around in his coat and produces a bundle of the sacred Senko Hanabis.

My ears start getting tingly, the hackles rise on my neck, and my wallet pocket starts throbbing. Furtively, I pull my coat down to hide it! Cain’t let him see. Cain’t let him find out that I don’t CARE what they cost! I just have to have these wonderful little twisty paper things.

I try to put on my stupidest, semi-interested, inscrutable Westerner’s face, one big “huh?”

I like this guy. He seems a little hungrier than some of his nouveau-riche fireworks company compadres. And he did arrive on a motorcycle, not a fancy dancy new car. I can work with this guy. And yep, he IS willing to make them.

Pricing is put off for another day, to be haggled back and forth by Matt and the factory owner and me, based in part on quantity I agree to order, packaging, and other factors.

We shake hands, I toodle off, all satisfaction and afterglow, with Anne and my pals, and I offer to buy lunch for all, secure in my final victory that I have found the elusive Senko Hanabis and will finally be able to get them to my insatiable customers in the good ole US of A.

But if you want to tackle the intricate mysteries of making Senko Hanabi yourownself, you can read Ned Gorski’s article below on making them. They are tricky little devils, requiring a fine balance of potassium nitrate, charcoal, and sulfur. And if you already have those three chemicals, you can do it easily with just a little tissue paper. Ned takes all the guesswork and hair pulling out of the process for you.

Senko Hanabi Sparklers, #NV0500

In the past, I’ve kiddingly told fellow pyros that, at one time or another, I’ve made, or at least have tried to make, every kind of fireworks device except for snakes. That was before I heard about Senko Hanabi, though, and realized that I didn’t even know what they are.

I’ve made some firework sparklers in years past, and Senko Hanabi are a kind of Japanese sparkler in the strict sense of the word. But, after a friend gave some of them to me last year, I realized I’d never tried to make anything like them.

According to Shimizu in Fireworks, the Art, Science and Technique (”FAST”), Senko Hanabi is a traditional Japanese firework, and essays about them date back to at least 1927. One Japanese-to-English, online dictionary spells it Senkouhanabi, and defines the word as “toy fireworks.” Hanabi means “flowers of fire,” and these sparklers produce miniature versions of them.

Senko is defined as “all ages,” and perhaps refers to the fact that this firework can be enjoyed by people of all ages. Senkou is said to refer to “incense stick” and this type of sparkler has, indeed been made on sticks, which resemble incense.

The word “sparkler” may be a bit misleading to us in the USA, though, because of what it brings to mind. Metal wires or wood sticks, dipped in pyrotechnic compositions, emitting bright sparks and lots of heat when they burn. “Be careful around your sister’s eyes with that glowing metal wire,” Mom would shout.

This Japanese version of the firework sparkler is much more delicate and subtle than what we are used to, though and a lot more safe as well. I remember how startled I felt when I first got one of these to work, and it began emitting amazingly complex, delicate, branching sparks, shooting out four to eight inches. Like fire-snowflakes, I thought. I was amazed.

After I burned through a pack of them, I decided to send my Mom and Dad a bundle of these colorful little sticks. My folks are in their 80’s and live in California, so I certainly wouldn’t have been comfortable sending them any real “fireworks,” but I just had to show them these mysterious little sparklers. I was excited as I imagined them going out onto their deck and burning a few of ‘em.

“You are going to be amazed by what you see when these little things really start doing their thing,” I told them.

Here’s a photo of an individual Senko Hanabi.

The bulging section toward the left end is what contains the sparkler composition. The comp is contained in twisted tissue paper, which can be fairly easily untwisted to empty the contents.

The composition is a very dark black powder. And there is not much of it in there. I have an electronic scale, which is precise to one-tenth of a gram. It would not register the weight of the composition that I removed from this sparkler. It barely covered the tip of a one-eighth teaspoon measuring spoon. Its quantity equals about as much salt as you’d get if you shook your salt shaker a couple of times.

The rest of the sparkler, the handle, is also composed of tightly rolled up tissue paper. It feels as though it has been stiffened with a bit of a binder or glue of some sort.

To get a Senko Hanabi to work, you hang the composition end of it straight down from your hand. Make sure you are in an area with no wind, steady your hand, and then light that lower end. To really see the effect, it’s best to do this in the dark, and in a ventilated area, but without wind, so you don’t have to breathe the strong sulfur smoke.

The tip will burn up to the bundle of composition, which will begin to slowly burn, and if you are holding it still enough, a little blob of orange, glowing, molten slag will form. This is reportedly potassium sulfide, which contains carbon from the charcoal.

Then, all of a sudden, this molten ball will begin to emit the most amazing, delicate, branching sparks, often looking like fire-snowflakes. When you see this for the first time you’ll be amazed.

I tried, over and over, to get a nice photograph of this phenomenon and failed miserably. This shot might give you the slightest impression of what the effect is like. You really have to see it in person to appreciate it.

There are several Senko Hanabi tutorials available on the Internet, and, as far as I can tell, all the information is based on the information contained in Shimizu’s FAST.

The black composition is a simple one, consisting of three basic chemicals: potassium nitrate, sulfur, and charcoal.

These are combined in a ratio of 60% potassium nitrate, 20-30% sulfur, and 10-20% charcoal. This is a typical black powder composition, but the quantity of the sulfur is doubled or even tripled.

Sometimes lampblack or soot is used instead of charcoal. If charcoal is used, the type of charcoal will influence the resulting sparks. Some folks use charcoal that is made of tissue paper or paper towel, soaked in a sugar solution, and cooked in a retort until it becomes a form of charcoal. See How to Make Charcoal , for details on cooking charcoal.

Shimizu also lists an alternate composition, consisting of 35% potassium nitrate, 45% realgar, and 20% charcoal or soot. Realgar is a chemical that is listed as a component of some old fireworks formulae, but it is seldom used nowadays because it has become unavailable, and it contains arsenic, which can be a bad thing in smoke if it is inhaled!

Note: I do have a small quantity of realgar, and I tried the above formula in Senko Hanabi. Shimizu states that realgar will produce “larger and more beautiful sparks than with sulfur.” In the minimal experimenting I performed using it, I did not find that it performed as well as the sulfur. And, when the composition burns, it emits a thick, yellow smoke, which I was not all that thrilled to be around.

My technique for making these experimental Senko Hanabi was as follows:

Weigh out chemicals in individual paper cups. Grind potassium nitrate and sulfur individually in a small coffee grinder until the chemicals are very fine. Combine and screen those chemicals with the airfloat charcoal through a 100-mesh screen several times.

I began by using 16.5 grams of the potassium nitrate, 6.5 grams of sulfur, and 4.5 grams of airfloat charcoal. (This is approximately a 60/25/15 proportion of the components.)

Cut a piece of tissue paper, 1/2″ x 2 1/2″.

With slightly dampened thumbs and index fingers, begin to roll the tissue paper up at the ends, as if I’m rolling a cigarette. (Having come of age in the 60’s and 70’s, I, of course, would know nothing about this process.)

I now dip the end of my 1/8-teaspoon, measuring spoon in my composition and scoop out just that little bit of comp. I tap the powder out of the spoon into the little, rolled trough that was formed in my tissue paper.

Then it’s just a matter of using my fingers to finish rolling the little sparkler and really twisting it into a tight little bundle. I like to hold my homemade sparklers with a pair of tweezers, or a hemostat, in preparation for burning it.

When I made the first sparklers, using the composition listed above, they burned far too fast and did not form the little ball of slag which is necessary for the resulting final sparks to let fly.

So, I started to add more charcoal, one half gram at a time, as one would do to slow down a black powder rocket composition. This did end up retarding the burn speed, but the slag ball and the sparks never ended up forming.

Back to the drawing board. Since the original comp was burning too rapidly, I thought I’d start with the charcoal and sulfur components, and slowly add potassium nitrate until hopefully the desired results were achieved.

I ground the 6.5 grams of sulfur in my small coffee mill, and screened it in with my 4.5 grams of charcoal. I weighed out the 16.5 grams of potassium nitrate and milled it by itself in the coffee mill.

Then I started to add the potassium nitrate to the sulfur/charcoal mix a little at a time, starting with 4 grams and adding it in 1-gram increments. I tested the composition after each increase in the oxidizer, and after adding 11 grams of it, the ball of slag started to form and it began emitting the sparks I was after.

With a total of 12 grams of the potassium nitrate in the mix, the sparklers were working very well, and when I added another gram bringing the total to 13 grams, they started to burn too quickly as in my first experiments.

This final formula is in the range of proportions that Shimizu demonstrated to work.

I tried both commercial airfloat and homemade spruce/pine airfloat charcoals, and they both worked well. The homemade charcoal produced sparks which were slightly larger.

I tried the lampblack that I had on hand in the formula, instead of charcoal, but I could not get it to work and produce sparks.

If I were going to make “production models” of these babies, I’d glue the tissue paper bundles to a bamboo skewer, or toothpick, handle.

Dr. Shimizu goes into much greater detail concerning the chemistry dynamics of the Senko Hanabi process, and other optional formulae, ingredients, and manufacturing processes.

When I first got into fireworking, one question was paramount in my mind: “How the heck do they do that?” I’ve continued to ask that about almost every pyrotechnic device I’ve seen, and I’m glad that Dr. Shimizu and others have left pointers along the way so that I could learn more about how these things are made.

Until next time, Enjoy!

Ned