What was Zincoshine and did they decide to use for a binder in October Sky?
Once the boys felt (particularly Quentin) they had reached the end of the utility of the rocket candy fuel, he suggested they use a combination of zinc and sulfur, as they felt it was more volatile and more powerful, exactly what they needed to continue their ever more impressive string of rocket launches.
The problem is that the first rocket explodes and they needed something to hold the powder together. After considering a number of options they decided that alcohol was going to be the best option so they went and got a gallon of moonshine from John Eye Blevin. It turned out that it worked really well so he called it Zincoshine after the ingredients.