To engrave metal, coat wax on the area to be engraved on the metal, use a nail for engraving, and apply acid on the wax in the engraved section. After a few minutes, take out the wax.
To coat wax on the area to be engraved on a metal, first melt wax on a stove or in a microwave. Take the wax in a saucepan, place it over the stove, and stir the wax at regular intervals till the consistency of melted wax becomes smooth. If using a microwave, place the wax in a suitable container, and microwave for 30 seconds on high. Then, stir the wax, and microwave for 30-second periods until the wax becomes smooth.
Dip the metal in the hot wax. If the metal piece is too large to be dipped in, apply wax on the area that is to be engraved by pouring it. Place the metal on a sheet pan, and let the wax cool and harden for several hours.
Engrave the metal with a nail tip. When engraving, write the message on the wax while allowing the nail tip to scratch the metal's surface. Apply acid over the engraved portion, and leave it there for about 10 to 15 minutes. When using acid, wear safety goggles to protect your eyes from its fumes.
Remove the wax using a craft stick made of wood.