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Your smoke bomb can be any shape you like. For puck-shaped smoke bombs, wrap the bottom of a soda can in aluminum foil and then remove the soda can. The foil will hold the shape. You may also want to use a ball, something square, or a simple design of your choosing. Shape the aluminum foil so the opening is facing up, then set the mold aside. Measure the sugar using a dry measuring cup to ensure you have the correct amount. Pour it into a standard sized 12in (30cm) skillet but don't turn the heat on yet. Do not use a measuring cup meant for fluids, as the measurements are different. Pour the potassium nitrate into the sugar. Use a wooden spoon to mix the two powders together until they are well blended with one another. Make sure the ingredients are mixed thoroughly otherwise you could end up with an unusual burn once you're done. Spread the mixture out in the pan once it's thoroughly mixed. You can purchase potassium nitrate at online chemical retailers or even at some large retail stores. Place the pan on the stove with the burner set to low and continue mixing the ingredients using long, slow strokes. Eventually, the sugar will begin to melt. Continue stirring the mixture as the sugar melts and mixes with the potassium nitrate. As the sugar melts and mixes with the potassium nitrate, the two will begin to form a liquid sludge. Once it has become liquid enough to roll around the pan, pick it up off of the heat and turn off the burner. Keep stirring the mixture as you remove it from the heat. Move quickly. The mixture will begin to harden soon after it is removed from the heat. Be careful not to spill any of the mixture as you do. Once there's a thick layer of the mixture on the bottom of the mold (it can be any depth you choose) set the remaining mixture aside. If there's enough left over you can always make another smoke bomb. Do not touch the foil once the mixture is inside it. It will be very hot. Leave the mixture in the foil overnight, then peel it off the smoke bomb. The smoke bomb itself is entirely flammable, so there's no need for a fuse. Do not ignite the smoke bomb indoors or breath the smoke that it produces when lit. Be extremely careful when lighting the smoke bomb, as it may produce more smoke than you expected. There is no fuse on the smoke bomb. To set it off, simply ignite any portion of it using a lighter or match, then set the bomb on the ground or another horizontal surface to burn. The smoke bomb may not burn with a visible flame but keep it away from anything flammable for safety anyway. Do not hold the smoke bomb while it burns.
Create a mold of any shape out of aluminum foil. Pour 128 grams (4.5oz) of sugar into a skillet. Add 192 grams (6.8oz) of potassium nitrate. Apply low heat to the pan while you stir the mixture with a spoon. Remove the mixture from the heat when it liquifies. Pour the liquid mixture into the foil mold. Allow the smoke bomb to cool and remove it from the foil. Ignite the smoke bomb by exposing it to a flame.