i bought some liquid stane around 20 odd months ago and still have a full unopened bottle left, it has been mostly stored in a cupboard but has spent a few months in the glove box of my van so chances are it could have frozen, is it still ok to use? if i leave the bottle standing long enough it separates into two sections of a milky liquid on the bottom and a more clearer oily liquid on top is this normal for this ? any info on wether this is ok to use would be great thanks