Egg Engraving

This is like engraving in reverse i.e. your name will stand out in relief from the shell rather than be etched into it.

You will need:

• Hard boiled egg
• Wax crayon
• White vinegar
• Large glass or bowl (big enough to hold the egg)
  

What to do:

Ask an adult to hard boil an egg for you. Print your initials or your first name, large and fairly thick, on the shell of a hard boiled egg with the wax crayon. Now put the egg in a glass large enough to hold it and add enough fresh white vinegar to cover it. Tiny bubbles should form on the egg which show that the acid in the vinegar is reacting with the shell. The shell under the waxy letters is protected from this acid action. In an hour or two, when the bubbling stops, replace the now neutralized vinegar with a fresh supply. After another two hours wash off the egg under running water. Rub your fingers over the letters and they should stand out in relief. You can even try to GENTLY remove the wax coating with a soft brush and scouring powder under running water.

What's going on?

An average eggshell is 2.35mm thick. It's made of 3.5% protein, 1.5% water, and 95% calcium carbonate mineral. It is this mineral that reacts with the acetic acid in vinegar. The wax protects the shell from coming into contact with the vinegar. If half of the shell has dissolved during the four hours, then it has only about a 1.25mm thickness left. So be careful!