Protecting Aluminum Powder From Water With Boric Acid

Read and review these Fireworks Safety Articles before starting any fireworks project.

Learn how to coat aluminum powder with boric acid to stop corrosion of the aluminum powder in firework star compositions.

Materials Needed

Joel Harmon was in a discussion on the PML about how to reduce the risk of a runaway reaction between aluminum powder and water in a star composition. Boric acid powder is commonly added to star compositions for this purpose, but Joel suggests a more effective approach. Thanks Joel.

"I use boric acid only in solution. I usually buy distilled water and put 2% (by weight) boric acid powder in it and let it dissolve. If the boric acid in solution that you are referring to is in water then you can probably use it as is. See how concentrated the solution is and use it appropriately. I once had a very well-respected firework builder tell me that putting boric acid in star compositions dry is a waste of effort because it can never really protect all that aluminum powder very effectively, as the boric acid doesn't fully dissolve (boric acid takes a while to dissolve and is very hard to dissolve). When boric acid is in solution it can coat every particle of aluminum powder in your star composition evenly. I have always used this solution idea and have never had degradation of effect."

To learn about pyrotechnic aluminum powder read these:

"Firefly Aluminum Powder"
"Aluminum Powder Mesh Sizes and Microns"
"Aluminum Powder Particle Shapes and Sizes"