SLIPPERY ROCK, Pa. (AP) – One tent promises you’ll “Have fun and learn to make almost perfect Gasoline Fireballs.” Another display provides tips on “Black-Powder-Coated Rice Hulls for Lift and Burst, An Easy Way, Using an Optimized Ball-Mill and Star-Roller.” You can also check out “Pyrobilia,” or collectible fireworks. Those topics and other explosive endeavors are on the agenda for about 2,000 members of the Pyrotechnics Guild International and their families who are gathering this week in western Pennsylvania for their annual meeting at a scene that’s part backyard laboratory, part country cookout.

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