I use cellulose thinners on [ on cellulose of course] but on various types of enamels ie engine enamel, brake caliper enamel, humbrol if I'm airbrushing as it's quire thin allready, hi build vinyl,hammerite, & there's nothing better for cleaning out brushes & spraying equipment than celly thinners, obviously try a bit on a small sample first, I always use 2pack etch primer on everything, alloy, brass, steel etc, & after spraying parts they go into the bottom oven of the rayburn to lightly bake dry.