How to Etch a Candy Tin

One 6V dry cell battery
Coarse grit sandpaper
Fine grit sandpaper
Crayons
One metal candy tin
Dust mask
Eye protection
Insulated copper wire
Wire cutters and stripper
A ballpoint pen or pencil
Hairdryer
A large glass or plastic bowl
Salt
Water

A good candy tin for this project is smooth rather than embossed and has enough room on the front to draw a design or image. I like to use the tins that Newman's Own and Penguin mints come in as they are free from embossing or other raised designs but any smooth tin will work just as well. Altoids tins used to work great because they were smooth but the new ones are embossed. This old, smooth Altoids tin was a fortunate find from under my sink.

Starting with the coarse sandpaper, sand off the paint on the surfaces you will be using. Sand in a single direction for a smoother finish.

Use a fine grit sandpaper to smooth the rough surface of the tin. Again, pick a direction and sand in it to avoid a grooving or crosshatching effect.

Now your tin is ready to etch!

Use a dark colored crayon to color in the side you wish to create a design on.

Once you've colored in the side of the tin you wish to use, heat it with a hairdryer on high until the crayon begins to melt. While the tin is still hot, fill in any thin spots of crayon wax using your crayon.

Use a pencil or ball-point pen to scratch out a design or picture on the tin. Don't try to scratch into the metal, just scratch through the wax. I like trilobites so I scratched a trilobite into the wax this time.

Cut the wires about a foot long, strip about an inch and a half (about three centimeters) of each end on each wire. Test the wires to see how you need to bend them to stay on the battery's contacts without allowing their stripped ends to touch each other or the other contact.

Mix table salt into a glass or plastic bowl of warm water until you can dissolve no more in it. Remove the negative terminal's wire, leaving the positive terminal's wire attached. Lay the positive wire's end in the saltwater bath.

Set one stripped end of the negative wire into the saltwater bath. Then set the tin into saltwater bath so the side to be etched is in the water above the negative wire end and touching it. Then attach the negative wire to the negative battery terminal. This will make a stream of bubbles come up from the wire's tip under the tin. This is normal and desired.

The gas made is hydrogen which is flammable so perform this part of the project away from open flame and in a well ventilated area.

Allow the tin to sit there over the bubbling negative wire for five to ten minutes then remove the negative wire from the battery.

Remove the tin from the saltwater bath and dry it off. Then scrub off the crayon wax and polish the tin with the fine sandpaper. Wash it gently with warm water to remove any metal dust and dry it gently with a towel.

You can now either coat the tin with a clear varnish or allow the natural patina of oxidation to age and enhance your etching.