Wipe Glass With Shaving Cream to Keep It From Fogging

The Problem

Glass fogs when moisture in the air condenses into thousands of tiny droplets that scatter light — a car windshield on a cold morning, the bathroom mirror after every shower. Wiping it clears the view for about a minute, then the fog re-forms, because wiping does nothing about how water behaves on the surface.

The Technique

1. Put a small amount of foam shaving cream on a clean rag — a dab, not a handful.
2. Work it over the whole glass surface.
3. Buff it off with a dry cloth until the glass is clear and streak-free.

Two things happen. The shaving cream's surfactants break down the oils and residue on the glass, so it comes out cleaner than a water wipe. And buffing leaves behind an invisible surfactant film that stops condensation from beading up — moisture spreads into a thin sheet instead of fog droplets, so the glass stays see-through.

Shown on car windows in the source video; the same treatment is the old barber's trick for bathroom mirrors, where it keeps the glass clear through a hot shower.