Understanding “Sacrificial Anode”

In today’s Discovery Channel program “Some Assembly Required,” I saw how a metal coffin casket was made. Besides the usual heavy metal stamping and automated welding machines, the topic of “sacrificial anode” was explained. In my opinion, this is probably the most important “technology” used in the design of the coffin. The sacrificial anode, normally made of zinc, was attached to the bottom of the steel casket to sacrifice itself to the oxidation (losing electrons) process with the soil outside, instead of the steel being oxidized. A Wikipedia explanation is here. I was surprised to know that almost all the water heaters has an sacrificial anode rod to perform the same function. A longer-warranty heater may have a larger or even two of the anode rods made of magnesium or aluminum. Here’s a good explanation for it.

I like this program. It’s entertaining and I usually learn something.