From Basic to Your Most Demanding
Surface Finishing Specifications
Exacting procedures, and an exclusive Library of Finished Die Cast "Plates," assures your satisfaction
Depending on the requirements to meet durability, protection and/or cosmetic appearance specifications, all CWM Al, Mg and Zn die cast components will receive from one to three standard finishing steps:
1. Post-Casting Deburring
Virtually all CWM die castings go through a basic mechanical deburring operation to prepare the part for final use or further post-trim finishing. This automated deburring step is used for rounding sharp edges, removing loose flash and debris, and smoothing and brightening the surfaces of die cast parts.
2. Conversion or Combined Conversion-Functional Coating
In many non-cosmetic applications, a conversion coating can serve as a component’s final finish or, when final painting is specified, as a preparation and primer.
Where a die cast component has a specific functional requirement, such as added corrosion protection, the need for added durability, and/or a semi-decorative appearance, one of the combination conversion-functional finishes is often recommended. Many of these coatings can serve either as a paint base or, in many applications, as the part’s final finish. And now a new EPA-compliant Trivalent Chromate Coating, that meets European mandates as well, can be used for Al, Mg or Zn die cast parts.
3. Cosmetic Quality Surface Finish
While final painting and plating of die cast housings and components is most often specified for cosmetic purposes, and to sustain their decorative appearance over the life of the part, other functional purposes of a final applied finish may be of equal, or of even greater, importance. These include: maximizing corrosion resistance, heat dissipation, and surface performance under abuse, and adding greater insulation properties.
Early consultation with CWM is especially important when painting or plating of a die cast part is being specified. Part design features and the type of finishing selected will call for tooling design modifications to insure that desired corrosion and protection properties are achieved. Some part features can be problematic for proper protection, with a modest redesign assuring finishing success.
CWM offers a wide range of painting applications for use with die castings in matching finished, mating parts produced in other manufacturing processes. These final die cast surface finishes include powder coatings applied electrostatically in finishes from fine to coarsely textured in a variety of chemistries, to liquid paint polyurethane and water-based finishes applied at various thickness and texture levels by electrostatic or conventional means.
CWM’s Library of Finished Die Cast “Plates”
To aid OEMs in accurately visualizing their die cast surface finishing options, and evaluating relative performance levels, CWM maintains a unique library of finished die cast “plates.”
Each library “plate” exhibits a coating applied under production conditions to the actual die cast alloy to be used for your product. The finishes cover all most widely used post-casting surface coatings and finishing alternatives available for die cast components in aluminum, magnesium and zinc.
A companion Comprehensive Surface Finishing Portfolio offers detailed information for each finish, by alloy on which applied, with recommended uses, advantages and limitations. You receive a clear picture of what can be expected in performance from alternate surface finishes.
(More on CWM's OEM Surface Finishing Resources, in column at right)
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