Final finish coatings 18 October 2018

By Mark Thurber, CEO at Maelstrom Chemical Technologies LLC

Small component manufacture is as general a subject matter category as one could imagine. Any spring, nut, screw, clip, pin, bolt, anchor, casting, stamping, fitting or assortment of these items – combined into a sub-assembly and destined eventually to be part of a finished article, could fall under this heading.

Even more obvious, yet easily overlooked, is that most items we use through every part of our day are simply collections of these sub-components, orchestrated to deliver a desired output. Your alarm clock that wakes you, the bathroom faucet, the coffee maker, toaster, door handle, automobile, parking meter, telephone, computer, printer, office chair, and on and on, are all a composition of small finished parts doing their intended job.

In manufacturing these pieces, each must receive its fair share of grinding, milling, rolling, bending, forming and heat treatment. However, the final coating the products receive before being packaged, sometimes comes down to ‘oil or no oil’. This seems an unfit finale when so many choices for highly functional, multipurpose coatings are now available. Moreover, many finishing formulas can easily add great value to parts with little or no added effort.

Storage and transport corrosion prevention
In our current global economy, manufacturing and assembly operations that once had occupied the same facility, may now lay at far ends of the Earth from one another. In such instances, raw parts may now have a chance to enjoy the fresh (and corrosive) sea air and weeks of storage, before ending up at their final destination. Old fashioned oil or wax treatments, though inexpensive, are marginally effective with savings being negated by cleaning and spoiled dunnage. New ultra-thin, dry to the touch, options are not only more effective and cleaner, but also may be applied in-process or in existing rinse tanks at the end of the processing line. Components that have benefited from post treatments of this type include steering gears, linkages, washers, castings, and stampings.

Without changing the invisible appearance and easy application, extra features can be incorporated into the same finish. Inspection enhancing colourants, friction modification, release coating, sealing, etc, can all be built into the same coating. Examples include Tectorius® Tec-Kote™ 756, an invisible, rinse applied, dry to the touch corrosion-inhibitor coating, designed specifically for overseas transporting and preserving of plain steel machined gear systems. Tectorius Tec-Kote™ 300 is another example. It is a translucent, dry film offering mild corrosion protection, high lubricity and very low particle generation. This product is found on a number of thread forming fastener products and assemblies with dissimilar metals.

Damage protection
Different options are available for parts that may be finely finished and require protection from damage. Specialised temporary coatings can be utilised to prevent scratching, chips, nicks, marring and can replace costly packing materials.

Tec-Kote™ 750 is a removable, water-based spray on shell, used to protect exterior automobile parts through transport and assembly to the vehicle. Products of this type come in a multitude of grades that can be sprayed, flooded, brushed or dip coated onto pieces. They can also serve simultaneously as corrosion preventatives and can be thought of as a liquid applied ‘shrink wrap’. These coatings can be thin or thick, up to 3mm, thus offering excellent chip protection, yet remain easy to wash off. These are often used for exterior automotive lenses, glass, emblems, appearance fasteners and lug caps, or on non-automotive building supplies like siding or corrugated metal. Weather resistant grades remain intact even in harsh conditions, until a specialised soap is introduced – triggering dissolution of the coating. In addition to being used for preservation of small components, complete automobiles or machinery being stored outside can also benefit from full coverage of these materials. Tec-Kote 756 has been tested for one year of outside storage conditions, meeting rigorous US automotive standards.

Permanent finish coatings
Choices of finished coatings available in the marketplace are quite extensive. However, thorough understanding of the specific intended goals, purposes, and environments, is key to getting the most out of your coating selection.

Driving appearance as the primary criteria can lead to overlooked properties that could greatly benefit the end product. After all, who would not want to offer their customer a ‘new and improved’ product simply by refining the goals and available products? Permanent, bonded surface finishes can impart wear resistance, lubricity, corrosion protection, dimensional control, and abrasion enhancement. Even then, close consideration must be made of the intended substrate in order to make the correct choice. Tectorius® Tec-Flon™ 6000 will not only impart durability and controlled coefficient of friction, but prevent adhesion of electro-coatings and paint up to temperatures of 400°C.

Opportunities for significant improvement, efficiency and optimisation of your finished article may be just around the corner. A simple change or implementation of a new final coating, could easily provide greater value to your customer, afford you advantage over the competition or simply fix a problem that drains your resources. Exploring what innovations are available and the willingness to depart from stale methods may be all that is needed to bolster your market position.

Claire Aldridge Editor t: +44 (0) 1727 743 889

Having spent a decade in the fastener industry experiencing every facet – from steel mills, fastener manufacturers, wholesalers, distributors, as well as machinery builders and plating + coating companies, Claire has developed an in-depth knowledge of all things fasteners.

Alongside visiting numerous companies, exhibitions and conferences around the world, Claire has also interviewed high profile figures – focusing on key topics impacting the sector and making sure readers stay up to date with the latest developments within the industry.