This a a Salt water etching tank that I'm using to etch a steel box made from 3/16" plate. I used Rubber cement to protect the areas I didn't want to erode away.
The salt increases the electrical conductivity of the water. (I've used baking soda in the past, but I was out so I tried out Salt and it works great)
The positive and negative leads from a car batter charger are attached to two steel plates. The plate the positive lead is attached to will corrode quickly. By adjusting the spacing between the plates in the tank you can vary the amperage on the charger: too close and you'll fry the charger, too far and it will take forever. I keep mine around 10amps; this is why you want an Amp meter on your charger.
I did selectively protect some areas of the metal being rusted by coating it with rubber cement. Paint works too but nail polish works better.
Tags: Saltwater etching Metal Art Steel Etching
