Through these openings pass the current and electrolyte to transfer the image of the stencil onto the base metal.

Because the electrolytes are salt solutions, any mark or etch must be neutralized by wiping with, or soaking in a neutralizing solution.

The Electromark method of marking metals permanently without distortion is simple and precise. Electromarking, therefore, is the most economical way to produce quality marks or designs on any bare metal.

THE BASIC EQUIPMENT

Power Units

Power units, which provide voltage and current to make the mark, come in a range of sizes. The size required depends on the area of the mark and the speed of the mark or the depth and speed of the etch. All units have an Off-On switch and an AC-DC switch to produce an AC mark or a DC etch (the reverse is true on aluminum). Most units have a rheostat to regulate the output voltage. The current required will automatically be produced by the unit unless it exceeds the output of the power unit, in which case a fuse or circuit breaker will "blow". All units contain banana or polarity receptacles for making contact through cord sets. The power units on the market today range from 5 volts to 40 volts and have an ampere output from 0 to 40 amps.

The DC on the power unit is used for electroplating or electroetching. In its normal use the DC will etch out metal leaving a frosty whiteness. This is called electro-etching.

Most power units and fixtures are trouble free, Corrosion can cause loss of full current flow thereby reducing the darkness of the mark. Make sure all contacts are clean and tight. After using this equipment, clean and dry it.

Power units should be returned to the manufacturer for any repairs. Charges for such repairs are nominal as most units last indefinitely.

In a few cases, there is need for a dark mark on surfaces which cannot be Electromarked. This can be accomplished by reversing the leads on the power unit and using special electrolytes which plate a contrasting mark on top of the surface. This is a process known as electroplating.

Recent interest in deep etches has given rise to power units which are of the heavy duty type, with pulsators and timers to produce more speedy and uniform results.