Introduction: Flash Cotton (Nitrocellulose)

About: I am a master's student studying Electrical Engineering and an alumni of FIRST robotics. I also love to tinker on my own, which is mostly inspired by the amazing people on this website!

Nitrocellulose is one of the best materials to use for low budget special effects, or just to have fun! This flash cotton can be used in many ways (as seen in step 4), and all of them are amazing to watch! They also make for amazing light paintings! See the pictures in the last step for examples.

This is part 2 of a 3 part project. See the last step for a hint of the next part!

Warning: This instructable can be dangerous if the proper safety precautions are not followed. Please be aware that handling a strong acid, such as sulfuric acid, can cause significant harm. Also, the nitrocellulose should be used responsibly, not to intentionally harm another living being.

Step 1: Materials

Sulfuric acid (H2SO4) (Lowes, Amazon)
Potassium nitrate (KNO3) (Lowes, Amazon)
Baking soda (NaHCO3) (Grocery store, Amazon)
Cotton balls (Local pharmacy, Amazon)

  • Safety goggles (preferably slash-proof)
  • Rubber gloves
  • Plastic cups or other plastic/glass containers
  • Marker
  • Beaker
  • Scale
  • Pan
  • Salt
  • Ice
  • Plastic/glass stirring rod (no metal!)
  • Bucket
  • pH strips (optional)

Step 2: Preparation

Measurement: To measure the volume of a liquid, pour 50mL of water into a cup, and mark it with a permanent marker. Now you can simply pour out the water and fill up the cup to the line with the sulfuric acid. This method allows the use of kitchenware for the actual measurement.

Using the method above (or a spare beaker if you have one), measure 50 mL of sulfuric acid

Next, use a scale to measure 35 grams of potassium nitrate.

Then, measure 4g of cotton (it should be about 8 cotton balls) using your scale.

Setup: To produce optimal results, the sulfuric acid/potassium nitrate bath should be chilled with salt and ice. Fill your pan/container with ice, a bit of water and some normal table salt (NaCl). The salt cools the mixture down to below freezing and allows the ice to last longer.  If the temperature outside is within a few degrees of freezing, the ice bath is not necessary.

Also, prepare the cotton balls by pulling them apart and making them as fluffy as possible. This ensures the cotton will be evenly exposed to the mixture.

Safety Precautions:
  • Have a bucket of baking soda and water solution nearby
  • Wear safety goggles and rubber gloves
  • Stay away from anything you don't want to get acid on
  • Have someone help you or be nearby

Step 3: Process

1.) Place the potassium nitrate container into the ice bath
2.) Carefully pour 50mL of sulfuric acid into the container of KNO3
3.) Stir thoroughly for about a minute
4.) Mix in the pulled apart cotton balls one by one
5.) If the mixture becomes too thick, add another 10-15mL of sulfuric acid
6.) Once all of the cotton is completely covered, let it sit for at least an hour
7.) Remove container from the ice bath to prepare it for rinsing

1.) Fill a separate container with warm water
2.) Place the cotton into this container and stir
3.) Repeat previous two steps 3 times (the pH of the solution is still going to be about 2.5, so be careful!)
4.) When disposing of the acidic water, be sure to neutralize it first by pouring some baking soda in it
5.) Pour some baking soda down the drain of a slop sink
6.) In the same sink, let lukewarm water run into the container for two minutes, stirring occasionally (this will also clean your drain!)
7.) If you would like, test the water's pH (mine was between 6-7 by this point), but it should be safe to touch by now

1.) Drain the water from the container
2.) Put the nitrocellulose onto a tray
3.) Pat with a paper towel
4.) Leave to dry inside overnight

Step 4: Using It!

Now for the fun part!
Only a few of the uses for this amazing substance are listed here.  Be creative and be safe!

Normal Usage:
Pull apart the cotton until it is very fluffy. Then simply ignite it!  

You can also use a wireless igniter (it uses a glow plug from a RC car) (instructable here):
Light it in your Hand:

For this demonstration, the nitrocellulose is pulled apart very well and searched for any clumps that could burn for longer. It is very important to be aware that this should not be done repetitively, for your skin will not like it.  If done properly, you should feel a small amount of heat, but nothing more.

Throw a Fireball:

This is the safer than holding it in your hand, but note that it has to be thrown right after it's lit.

Coming Soon!

Stay tuned for part three!

Don't forget to comment if you liked it!

Sources: Nighthawkinlight

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