Hey duncandahusky!

[feren]

After I got out of the shower today I tried your trick of defogging the bathroom mirror by spreading shaving cream on it.

Holy crow, that really works!

Comments

[roho.livejournal.com]

You fool! Now the fog will grow back even faster and thicker!

[frysco.livejournal.com]

But then you have to spend more time cleaning off the shaving cream from the mirror?

Um - I don't get it.

[duncandahusky.livejournal.com]

Nah, you just wipe on a small amount of shaving cream (or any soap, really), then wipe it right off again. The trick is, you leave an invisible soap film on the mirror. When water droplets coalesce on the film, they form a surfactant solution with the soap. The surfactant solution has a lower surface tension than pure water, so this causes the water to spread out instead of beading up. This means you get an invisible layer of water coating the mirror, but no fog.

The downside to this is that as you're forming a solution with the soap film, you're also stripping the film away from the mirror. This is why after a few showers you'll need to re-apply soap to the mirror.

Products like Rain-X use similar principles, except that they use a silicon compound that has a greater affinity for the glass. That's why it sticks around for weeks instead of hours or days after each application.

Glad the trick worked, Feren!

[genet.livejournal.com]

I wondered what the hell happened to the mirror. Guess now I know! ;)

[feren.livejournal.com]

I'll get the mirror with electrolysis!