Making fireworks in Bengal

Since my childhood, I saw my uncles and my dad making firecrackers at home during Diwali. We were not allowed to go anywhere near the activities, however I was fascinated with the process and the result. When I grew up, me and my brother Suvro used to make fireworks using formulas from our Dad's notebook.

I was searching for other formulas to expand our range of display and though I came up with many formulas, however most of the formula consists of chemicals that a common man cannot get in India, especially in Bengal.

So, for the benefit of all other enthusiasts, I am sharing our formula of making different fireworks. Please feel free to let me know if you could make them successfully. I would happily extend any help or information to help you...
Here is the most common formulas to get you started. Please note that procuring the materials is not very tough, if you live in a city. However, the process is very laborious and takes a lot of patience.

Please ensure your and other's safety. These are fun things if you follow the instructions properly.

***KEEP THE CHEMICALS AWAY FROM CHILDREN***

BOSON TUBRI [AMBER]

Materials required [by Mass]:

1) Sulfur (Gondhok) 4 part
2) Potassium nitrate  (Sora) 16 part
3) Charcoal (Kath Koyla) 3 part
4) Iron fragments (Loha Chur) 12 part
5) Terracotta Container (Tubrir Khol).
6) Paper and soil to seal.


STEP 1 : Curing the container.

You get to buy these chemicals and the terracotta containers in various shops right after Laxmi Puja. Keep your eyes open and you should be able to spot the containers in gunny bags outside the shops. They come mainly in 2 different sizes - Big ( 1 chotak)  and small (1/2 Chotak). A place called 'CHETLA' near kalighat temple is the place from where I buy my materials. But you should get them in your locality also.

I prefer the smaller containers - there is no particular reason behind this. I just do. You can buy either of these two. The size really doesn't matter, but the quality most certainly does.
While buying, reject all those container that has cracks and not well burnt (look for deep brown colour, they are the best).

Once you bring them home, take a screw driver or a thin file. Make the smaller hole (The exhaust) slightly bigger and smooth. It is very important to get the size correct, as smaller holes will make the pot burst and bigger holes will reduce the height of the fountain considerably. If I have to give you a reference, make the hole as big as 1/8th of an inch. couple of tests should give you the right idea.

Once you are done with filing the exhaust end of the containers, put all of them in a bucket of  water for about 5 min and put them out in the sun to dry completely. This process makes the container harder and there will be lesser chances of the containers bursting. That's it... you are done with the container part.

Next, the mix

Sulpher (Gondhok)

 Sulpher comes both in stick and powder form. It is better to buy the sticks and prepare the powder at home. This way, you will end up with better quality of Sulpher.

Get a grinding stone ( I use a "Shil Noda". It is essentially a flat stone surface, and a cylindrical stone to grind by hand. It is commonly used in Indian kitchens for grinding spices.)
Grind the Sulpher sticks to a fine powder, and sieve it through a piece of cotton cloth over a newspaper. You will get fine powder on the paper, and coarse sulpher will remain in the cloth. Put those coarse sulpher back for grinding and repeat the process till you have sufficient amount of fine powdered Sulpher. Pack it nicely in a newspaper and put it away. You are done with the Sulpher.

Potassium nitrate (Sora)

Potassium Nitrate or 'Sora' comes in big lumps. you have to prepare it the same way as sulpher, and put it aside. Make sure that the Sora is very dry. Do not keep it open for too long, as it attracts moisture. Damp Sora is useless and will make you entire composition go dud, so be very careful.

Charcoal (Kath Koyla)

Is the messiest of all the components. It almost always comes moist from the shop. Dry it out in the sun before you sieve it. The process is same as before.

You are done with the basic preparation of the components. Not it is time to mix everything nicely. Follow this mixing process, and you cannot go wrong. ;-)

Preparing the Mix

Take 16 parts of Sora and 3 parts of charcoal. To make things easier for you, for every 160 grams of Sora, mix 30 grams of charcoal. Heap these two together and put 4 parts (40 gms, if you are following the  measurement I have given as example) of Sulpher to it. Now mix it throughly. There should be no lump in the mixture. When you see that the small yellow lumps of sulpher has vanished in the mixture, you will know that your job is done till now. Add the Iron Flakes (after taking away all non-iron materials from it) and again mix, throughly. Go ahead and take a break. Your charge is prepared.