If you’re a tire dealer that currently provides steel wheel refinishing to your commercial truck tire customers, it may be to your benefit to take a close look at recent progress in new machinery and processes for inspecting and refinishing wheels.
If you’re a fleet maintenance manager facing dozens of well-used steel wheels, it®s a good time also to look at some of these technological advances, especially if you®ve been frustrated by negative past experiences.
Either way, a lot has changed in recent years, all to the good. And, there are some important safety issues you also need to consider.
The convergence of several factors necessitates closer attention to the condition of steel wheels than was, perhaps, afforded in the past.
First, new-generation radial tires are lasting longer than ever before. This means more elapsed miles between tire/wheel dismount intervals, historically the most convenient time for wheel inspection and refinishing. And, the last thing you want to give rust is more time.
Secondly, over the last few years, many northern states have begun using new, highly aggressive types of road-clearing chemicals, products that are much more corrosive than traditional road salts.
Thirdly, while wheel condition checks are a component of most vehicle inspection programs both by in-house and state/federal on-highway inspectors ®“ extended maintenance intervals and emphasis on maximizing vehicle uptime (via minimizing in-shop time) hinder frequent visual inspections of wheels by technicians.
In the face of these factors, more fleets now place a high priority on maintaining a professional appearance, for both their personnel and truck equipment that interfaces with their customers. After all, trucks represent the “first face” of the trucking company to shippers. Smart fleets think of their trucks as rolling billboards that always need to look good.
For a tire dealer, investing in updated refinishing machines can certainly enhance productivity, customer satisfaction and, ultimately, profitability. However, as with many such technical processes, the devil is in the details.
It makes good business sense, then, for both dealers and fleets to study alternative offerings, examine the experiences of competitors and agree on real needs before leaping into the future.
Nearly all steel wheels today are factory finished with heat-cured powder coat instead of with older solvent- or water-based paint. Powder coatings certainly deliver enhanced finish durability. But when the time for refinishing finally arrives (and it will) powder coats are more difficult to remove than paint.
In general, the goal in prepping a wheel for refinishing is to remove the old paint finish completely with minimum disturbance to the bare wheel surface. Older-style sling box blasters, designed primarily for removing solvent-based paint, are hard pressed to remove newer powder coats without resorting to extended cycle times and/or the use of larger, more aggressive shot mixes and grit-blasting media.
As a result, the cleaned metal finish can become uneven, or pocked, in appearance. This rougher surface, in turn, requires thicker paint films to obtain a smooth, glossy appearance.
Wheel manufacturers recommend that total paint depth not exceed 3.0 or 3.5 mils. Excessive paint thickness can affect dimensional tolerances, which could lead to a loss of initial lug nut torque over time.
When tightening lug nuts while remounting a newly painted wheel, excessively thick paint films get compressed in the hub-to-wheel clamping area. In time, the paint in that area deteriorates, lessening the effectiveness of fastener torque. And, remember, there are a total of four surfaces to consider for paint film compression in a set of duals.
New refinish systems incorporate advanced blast media delivery. This allows removal of powder-coat finishes using smaller, less-aggressive shot material for example, SAE size S170 shot. The result is a smoother metal surface that requires less paint for good coverage, durability and a high-gloss appearance.
Some of the latest refinishing systems also provide advances in powder-coat materials, curing-oven designs, electronic system controls and monitoring. Many can produce refinished wheels that closely resemble new, powder-coated wheels.
While numerous variables can affect the durability of any paint finish, two are of primary concern and should be considered when selecting wheel refinish machinery, processes and labor.
First, is surface preparation i.e., cleanliness. This has much to do with operator training, the handling of the wheel prior to paint application and removal of all surface contaminants prior to painting.
Typically, new wheel manufacturers use a multi-step process prior to topcoat painting. This pre-paint process, at minimum, includes alkaline cleaning, rinsing, zinc phosphatizing, primer/sealing and a second rinsing.
Cleanliness is still key. Since the quality and consistency of labor is important to the final product, smart fleets feel observation of the process and inspection of potential locations are important components of their vendor-selection procedure.
Secondly, there is a major process difference between new wheel painting and the most current refinishing operations namely, use of a primer between the bare metal surface and the top, or color, coat.
Most OE wheel manufacturers consider a high-quality primer, such as a zinc-rich coating, to be mandatory. This type of primer provides adhesion and a degree of sealing between the bare metal and the paint coat.
The topcoat, on the other hand, is primarily intended to cover, fill and cure into a smooth, glossy finish that provides protection from the elements, various road clearing agents and repeated cleanings, which are often accompanied by high-pressure sprays and detergents.
The primer functions, in essence, as a transition coating between the metal and the color coating that greatly enhances durability of the final finish. Salt-spray resistance of three to five times that of topcoat alone is a common claim made by the makers of these new, two-coat systems.
Before You Proceed
Like most premium products, extra steps and materials bring associated costs. The preferred primer is also available in powder form and typically requires an additional spray gun and partial oven curing prior to topcoat application. Some refinishers estimate the added cost to be in the $4- to $5-per-wheel range. Given the durability, appearance and reduced maintenance advantages of the two-part painting process, it could be a proposition worth pursuing.
Ultimately, of course, fleets will determine the perceived value of a wheel refinishing service, based on their needs, service conditions, trade cycles, etc.
With the advent of new technology in this particular area, tire dealers have the opportunity to upgrade fleet customers through education, good technical salesmanship and positive differentiation of service offerings.
Certainly, the packaging of quality new or retreaded tires, mounted and balanced on quality refinished wheels (with appearance and durability approaching that of an OE offering) is a cost-effective, value-added proposition that offers obvious competitive advantages to both the fleet and its dealer.
This proposition only works, however, if both parties also agree to a system that not only affords a professionally refurbished tire/wheel assembly but one that also optimizes on-road safety.