Here’s how to make beautiful red Strontium Nitrate & Steel Powder Sparklers like you see above:
|Strontium nitrate||200 grams|
|Aluminum, bright flake, -325 mesh||32 grams|
|Airfloat Charcoal||2 grams|
|Boric Acid||6 grams|
+90 ml water and alcohol solution
(drug store rubbing alcohol is fine as is)
All chemicals must be fine powders. Grind any components separately that are not already fine powder (if any). Mix together all your sparkler components except dextrin. Add 25 ml of alcohol-water to dextrin and stir until it becomes a paste.
Break up or discard any large clumps that form in the dextrin paste. Add paste to dry chemicals mix and stir. Add 65 ml more alcohol-water solution and stir til smooth. Dump sparkler mixture into 41 mm OD x 12″ long test tube (or pipe, whatever). The wet sparklers composition should be 7″ to 8″ deep.
Dip sparkler sticks or wires (bamboo skewers work fine) into mix and let dry 24 hours. Then apply 2 more coats in same manner. If needed, add about 5 ml alcohol solution to re-wet mix. Let your sparklers dry for 24-48 hours.
The residue left after you dip the sparklers is fun to let dry in a pile and light on fire on the ground, too.
- You may have to adjust the volume of alcohol solution to make the sparkler paste consistency right.
- Sparklers may be difficult to light. Propane torches or butane cigarette lighters work well. Sparklers can also be lit off each other. I sometimes use a black powder/dextrin slurry prime just for the tip of the sparklers.
- When the sparkler comp dries, you may see rust from the steel. Altho coating the steel powder with linseed oil can prevent this, if you use your sparklers quickly after they dry, the rust will not create any problems for you.
- The paste for the sparklers may be a bit clumpy. Try to break up the clumps or thin your slurry just a little. Better mixing will not hurt the sparklers’ burning at all.
These sparklers actually burn a little better than commercial ones you can buy. They last longer, too!
This begs the question: “Do I need to coat my steel powder, and what should I coat it with?”
It is true that steal powder will rust in some comps, especially when wet or in comps containing potassium nitrate. Should you avoid steel powder altogether?
Nope! Steel powder makes beautiful, delicate branching sparks for fountains, wheels, hummers, and sparklers.
So how do you handle using this perishable chemical in your fireworks?
First if you do not need to wet your comp with water (such as a in hummer or fountain), or if it can be dried and used quickly (such as in a sparkler) the chance of rust being a problem is limited.
You can get away with using uncoated steel powder as long as it is not going to be stored too long (should be ok for 1-3 months).
But what if you need to make up some stars that will dry slower? Or what if you want to store that fountain for months and months?
The answer is simple:
Coat the steel powder with WD40 spray.
Spread out the steel powder on a sheet of wax paper and spray the powder with a light coat of WD40. While the material is still wet roll it back and forth to make sure all of the material is coated.
Once dry you may coat it again. The more coats the better the shelf-life will be. However, if you go beyond 2-3 thin coats the WD40 can start to inhibit the powder’s function and slow the burn rate.