Section 13: Material Engraving Techniques
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Anodized Aluminum
Anodized aluminum comes in a variety of colors and can usually be easily engraved
with a CO2 laser. Black anodized aluminum is great to work with because it turns
white when lasered. Black anodize provides the best contrast of all of the colors of
anodized aluminum. Some colors of anodize – red for instance – will not turn
completely white when laser engraved. Red anodize will produce a light pink color.
Performing a second pass can see some improvement but usually a slight shadow of
color will remain.
Engrave anodized aluminum at high speeds and low powers for crisp, clean images.
Too much power applied to the anodized coating will distort the engraving and tends
to over-burn the image.
Warning! Metals are reflective, and using full power will potentially cause
damage to the machine.
Brass - Painted
Brass Background
Un-coated brass cannot be laser engraved. In order to engrave brass with a laser you
need to use brass that has some sort of coating – typically paint. The laser removes
the paint and exposes the brass substrate. There are three basic types of engraving
brass available to engravers but they are not all compatible with the laser.
By far, the most popular laser brass is actually brass-coated steel. First, a steel
substrate is coated with a thin layer of brass. Next, the brass is polished to a
reflective finish and a coat of lacquer is applied to the brass – Victory’s LaserBrite™
product has a lacquer finish. Finally, a paint coating is applied on top of the lacquer
for the finished product. When laser engraving brass-coated steel, you are removing
only the paint and exposing the polished brass coating that is protected by the lacquer.
The lacquer prevents the brass from oxidizing and the bright reflective surface will
stay bright for years.
Some manufacturers also sell painted brass that is solid brass, not brass coated steel.
If the brass is polished before the paint is applied you will have a nice reflective
engraved surface. If the brass is not polished, the result will be a dull, tarnished brass
that will require a secondary polishing process after laser engraving. This is time
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