Coating Metal Parts The Next Step
A s the industrial world continues to evolve, the need for different coatings of metal surface changes as well. The challenges raised by the final owner of a given part continue to become more complex. Any number of matters need to be considered when choosing the appropriate finishing applicator.
Just like a metal fabricating and metalworking facility, there are many different levels of applicators in the world of the coating. Choosing the correct finisher is an important and often overlooked step in the final phase of manufacturing.
Let’s begin by reviewing some of the key issues:
• Consider logistics. In some instances, the location of the finisher is critical, as freight influences the final cost of the finished good. Some applicators have their fleet of trucks.
• Are you looking for organic finishes (paint)? If so, selecting a finisher that meets your quality requirements, as well as the specification of the final OEM, is a consideration. The size of the parts to be processed is often a limiting factor. In other words, is the paint booth/tank/e-coat tank able to accommodate your part size.
• Perhaps you are looking for inorganic finishes. The same considerations should be reviewed, as noted above, for organic finishes. Some OEMs specify very specific process chemistry, and not all applicators will have those finishes or chemistries available.
Technical Centers with large part process capabilities in house to provide products like sample runs of various coatings
• In today’s world, often, one coating layer is not enough to meet the decorative or corrosion criteria of the end-user. This is where things become more complicated. Looking for an applicator that can provide both organic and inorganic finishes is a key element in this arena.
• So the finish could be zinc or zinc/nickel electroplating, followed by a trivalent RoHs compliant passivate, followed by an inorganic finish such as
• Wet Paint
• Adhesives (rubber bonding)
• Zinc Flake
All of the above matrix coatings offer an entirely different perspective and performance characteristic that is NOT available from a single layer of a given coating. Working with an applicator whose chemical supplier has all of the finishes required will eliminate finger-pointing if there are coating issues.
• Consideration of final coating thickness is also a critical element when choosing an applicator. In the business of dip/spin zinc flake coatings, appropriate equipment is needed to minimize head or thread fill (for fasteners) or tapped hole fill. Not all applicators have this application equipment available.
• Does the applicator have a quality system in place? Such accreditations like NADCAP, CQI, or xyz or abc may give you the quality level that you are looking for. Not all applicators have advanced quality systems.
• Does the part have to mate with another part from a different source? This could raise questions regarding decorative “color matching” or “galvanic corrosion concerns.”
• Does the applicator have access to a technical center that can apply various coating types for evaluation? Can the technical center run the necessary corrosion tests that are required?
• Does the applicator have all of the tooling needed, or will new special tooling be necessary. Perhaps they make their own fixtures. In some instances, the company supplying the coating materials to the applicator has significant resources at their disposal. This might include the following:
• Technical Centers with large part process capabilities in house to provide products like sample runs of various coatings
• Metallurgical and analytical laboratories that are able to look at surface conditions as well as process analytics. Both aiding in defining a process or identifying the root causes of defects
• Multiple coating capabilities. This offers the OEM or Tier the opportunity to explore all types of coatings or in some cases, coatings that consist of both organic and inorganic coatings.
• A catalog of already proven finishes of both single coating outcomes as well as multi-coating outcomes. This can often supply “off the shelf” results aiding in the fast design of the final finish.
• Global services, allowing for cut and paste of the desired finish(s) applied elsewhere in the world for uniform supply chain results.
When faced with the challenge of defining a coating type as well as an applicator network that meets your needs, folding in a coatings manufacturer can often shorten the cycle to market entry