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.