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Time Needed for Student Project to Demonstrate Corrosion

I see a lot of questions regarding mediums for demonstrating corrosion. My question is how long do I need to allow for corrosion. Does it occur in a day, a week, a month? I am working with different common drinks such as Coca-cola, orange juice, etc. and how they effect certain types of metal. I want to make sure that I have time to successfully collect enough data for my project. Also, I would like to know what you believe would be the most effective metal to test on. Steel, iron, or another common metal?

Marie R.
Student - Carmel Valley, California, USA
August 31, 2011

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August 31, 2011

Hi, Marie.

An important part of a scientific experiment is repeatability. So what I would use for the metal would be sanded U.S. pennies. Pennies issued after 1982 consist of a solid zinc core with a copper plating. Sand the copper off and you should have something that corrodes pretty easily and which is very repeatable.

I would keep a lab book and make a quick notation of what I see every day for two weeks. Probably no need to go beyond two weeks, and even then you may be into evaporation problems.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

The modified pennies should not lay on the bottom of the beaker. I would hang them with plastic fish line from a glass rod on top of the beaker.

James Watts
- Navarre, Florida
September 2, 2011