What each one is
FLUID FILM® is a lanolin-based film — refined wool wax and corrosion inhibitors — that goes on wet and stays that way. It does not cure; it creeps. Corrosion Free is a thin-film, dripless product that dries to a clear coating with a corrosion inhibitor in it. Both are sprayed into the same places, both are reapplied annually, and both are a great deal better than nothing.