When you need to make deep etches, look at our specially designed heavy-duty metal marking systems. They make the etch by using direct current (DC) for long dwell periods. The longer the dwell, the deeper the etch.
As the etches become deeper, they tend to get fuzzy at the edges because the current flow cannot be directed straight downward. The appearance of the deep etch is improved by light polishing with a crocus cloth.
When making deep etches, it is imperative that you use a deep etch pad. We have deep etch pads available for bench markers, handmarkers, and marking cartridges. You will usually get best results with the marking cartridges.
Unlike a normal marking pad, a deep etch pad consists of a highly fibrous material. The fibers of this material, with slight pressure, will push electrolyte through the fibers of the stencil. This allows current to flow freely and easily, rapidly removing the metal. Of course, since the electrolyte is a good conductor, it is necessary to keep the deep etch pad saturated with electrolyte. The deep etch pad and the excess electrolyte keeps the stencil cool and increases stencil life.
When making deep etches, remember to use very light pressure. Usually, the pressure of the marker itself is sufficient. Excess pressure pushes the electrolyte out, drying the pad and destroying the stencil.
In general, a heavy-duty power unit makes etches approximately .0005 inches deep in less than ten seconds. If uniform depth is necessary, use a power unit with a timer. The current will then flow the exact amount each time.
Where etches from .0005 inches deep to .005 inches are required, use a pulsating power unit with a timer. With this, the current can automatically be cut off and turned on, so the electrolyte can flow back into the etch. And, the deep etch power unit creates such heat after six seconds dwell time that unless the current flow is broken up by a pulsator, the stencil will burn and the pad will dry up, creating a poor mark.
If you are considering a deep etch, we advise you to review the specifications and your needs carefully. Customers often ask us for a deep etch to the depth of a steel stamp, but this depth is costly and usually not needed. A depth of .0005 inches is deep and very hard to wear off. Usually, if there is .0005 inches of wear, the part itself is worn out and ready for replacement.