Penny Cleaning Experiment
When we were working on the coin collecting page, experts said that you should be careful about cleaning coins that might be valuable.  At the same time, we found a giant list of solutions and products that you can make and buy to clean pennies. The interesting part was that these lists gave results that they had found by using the solutions.  We wondered if we would get the same results and decided to try it to see.
     Remember, two people can do the same experiment and get two different results. This is because something might be just a little different in how the experiment was done or the solution made.  For that reason, we decided to go into the experiment with an open mind and not assume that we would get the same results as we saw online.
     The tables below contain our experiment information.  The first box is the solution or product we used, the second column are the before and after cleaning pictures (top is before, bottom is after) and the third column is a film clip showing how to clean the penny using the solution.
 
PROCESS: BEFORE AFTER
Vinegar and salt:

1. Fill a glass with vinegar and add a teaspoon of salt and mix it.

2. Put the penny in and leave it for 5 minutes.

3. Take it out and rub it with a paste of baking soda and water.

4. Wash and dry the penny.		 Penny before cleaning Penny after cleaning
Tabasco sauce:

1. Put enough sauce in a container to cover the penny.

2. Leave it for 3 minutes.

3. Take it out and rub it with a baking soda and water paste.

4. Wash and dry it.		 Penny before it was cleaned Penny after it was cleaned
Ketchup:

1. Put enough ketchup in a container to cover the penny.

2. Leave it for 3 minutes.

3. Take it out and rub it with a baking soda and water paste.

4. Wash and dry it. (Video in block above)		 Penny before cleaning Penny after cleaning
Bathtub/shower cleaner:

1. Spray the coin 2 or 3 times.

2. Wait a minute or more.

3. Rinse and dry it.		 Penny before it was cleaned Penny after it was cleaned
Copper cleaner

1. Wet the coin.

2. Rub the cleaner on the coin according to the manufacturer's instructions on the cleaner.

3. Scrub the coin, rinse it, and dry it.

 Coin before cleaning Coin after it was cleaned
Magic Eraser

1.  Wet the eraser and coin.

2.  Scrub for a couple of minutes.

3.  Rinse and dry.

 Penny before cleaning After cleaning with Magic Eraser

   We read what should happen in this experiment before we actually did it.  That wasn't a good idea because we didn't find the expected results at all.  We read that people were getting pennies really clean with the Magic Eraser and that just wasn't what we found.  We even found that the shower cleaner made the penny look dirtier! According to our experiment, the best cleaner was ketchup, followed by Tobasco sauce and copper cleaner. The worst cleaner was the shower cleaner.  It was exciting to see the tarnish come off of the pennies!  Happy cleaning!

Citations:

"Cleaning pennies."  11 Mar 2009.  <http://www.miamisci.org/ph/lemonjuice.html>.

"How to clean pennies."  11 Mar 2009.  <http://www.wikihow.com/Clean-Pennies>.

"What juice cleans pennies best?"  11 Mar 2009.  <http://www.finishing.com/faqs/pennies.html>.

Graphics:

Pictures of coins were taken by the team.