- a car battery charger
- a saturated salt solution
- an metal object to engrave
- masking tape (plain adhesive tape works)
Cover the parts of the metal object you don’t want to engrave with tape (do one side at a time, because you need a place to make electrical contact).
Mix vinegar and salt.
Clamp the + clamp onto the metal object.
Put a q-tip in the – clamp, so it touches the cotton
Dip the q-tip in the salt solution (do this frequently)
Rub the q-tip on the exposed metal, it will start to bubble and foam and get dirty. Don’t touch the metal directly with the clamp, you don’t want sparks
Change the q-tip when it’s become too dirty. Wipe the metal and the – clamp from time to time.
Ventilate your room because the chemical reaction stinks.
Work evenly along your surface to engrave, continue until it seems engraved deeply enough.
Remove tape and admire.
You can re-apply tape on small sections and engrave it some more if needed.
Some other thing I did with this process: