Considering the intense use demanded of most industrial and defense equipment, simply painting the bare metal components won’t suffice. In most cases, they must undergo a rigorous mechanical cleaning and/or phosphate pretreatment process to prepare the surfaces. This ensures the cleanest possible surfaces and the most complete adhesion for whatever coatings will be applied. Without these processes, even the strongest coating may fail to adequately adhere, resulting in corrosion and accelerated wear. At Rhinehart Finishing, we utilize automated and manual blasting equipment for product surface profile preparation on various products. We use a variety of media for blasting.
It's important to note that the specific methods of pretreatment used and the number of phases required ultimately depends on the condition of the material to be treated. In addition, the configuration of the piece and the performance requirements of the phosphate coating also make a difference. This is why we develop customized pretreatment plans designed specifically to meet the needs of the client and the products. With our expertise, we can create a solution that will result in the best overall finished product. Whatever the situation calls for, we are there to deliver expert services that provide exceptional performance.
Why Pretreatment Quality Directly Impacts Coating Longevity
Having an effective pretreatment process can be essential for ensuring the long-term performance of coatings. Without the right pretreatment, there’s an elevated risk of coating failure due to adhesion loss, chipping, underfilm corrosion or blistering. Mechanical and chemical pretreatment methods create the surface conditions and chemical states required for the most effective bonding with coatings at the molecular level.
Coatings intended for use in high-wear or corrosive environments such as those encountered by military, transit and agriculture equipment benefit from using zinc phosphate and media blasting techniques in tandem. This prevents delamination and preserves the integrity of the coatings. It also enhances the consistency of the finish, reduces the need for costly rework and contributes to a reduction in warranty claims or in-field failures.
Precision Blasting Media and Methods for Any Substrate
In terms of physical pretreatment, Rhinehart uses a variety of mechanical metal pretreatment solutions based on the particular substrate and Ra profile requirements. These include steel grit, aluminum oxide and glass beads. Our blasting capabilities ensure a consistent surface profile for optimal coating grip and powder hold, while at the same time preserving part tolerances and fine geometries.
Based on the part and the project, we offer manual as well as automated mechanical surface preparation. The former allows for more control with complex or low-volume parts, while the latter ensures repeatability and higher throughput. No matter which technique works best for the situation, our blasting surface prep protects the integrity of the coating for the highest levels of field durability under vibration, impact and thermal stress.
Zinc Phosphate Pretreatment
Our state-of-the-art zinc phosphate pretreatment system offers you the best of all worlds by providing high-quality cleaning and surface preparation. Our zinc phosphate is certified by the Department of Defense System to TT-C-490, Type 1 — a service not only valued by our military clients, but also by our commercial customers.
In this process, parts are treated with an inorganic coat that renders the surfaces inert and smoother than if left untreated. This helps paint or powder adhere to the parts more successfully and with less chance of blistering.
Compared to similar types of paint and powder coating pretreatment systems, zinc phosphate offers numerous advantages. For example, it can be used to pretreat products using a mix of metals without modifying the formula to account for varying rates of corrosion resistance, unlike using iron phosphate for coatings. This process also provides enhanced protection against oxidation. Because it creates its own coating on metal, a phosphate wash before painting also results in faster and more complete adhesion.
When compared to iron phosphate processes, zinc phosphate metal prep offers some significant benefits. For example, it is much better suited as a paint base for parts and components that will be exposed to high-corrosion environments. Although iron phosphate is less expensive and results in parts that are lighter in weight, its performance under corrosive conditions makes it the less-effective choice. In addition to this, zinc phosphate for coating prep also results in fewer rejected parts, resulting in substantial cost savings and greater efficiency.
Other benefits of this process include higher throughput, decreased downtime and less maintenance required for the finished components. These are due to the exceptional durability and reliability of the products once the coating process is completed. All these advantages add up to make zinc phosphate pretreatment highly effective and desirable for manufacturers who want their products to last.
Other Pretreatment Options
We offer additional paint pretreatment options as well, including chromate conversion of plating. We have a network of qualified and certified plating houses that work closely with us to meet all your needs. Additionally, we are in the process of adding passivation and non-hex chromate pretreatment systems to our facility.
Why Choose Rhinehart Finishing?
Our considerable paint and powder coating expertise, combined with our state-of-the-art facilities and equipment, make us a leader in the finishing industry. We pride ourselves on providing a level of service that is virtually unmatched in the marketplace today, as evidenced by our military certifications. With our complete pretreatment and other services, our customers can be assured that their essential components will be fully protected from the elements as well as the wear and tear they’ll experience in the field — no matter what the conditions.
We have the capabilities and the know-how to provide practically any type of coating service you need. We’ve served clients in some of the most demanding and challenging industries in the world, and we can leverage that experience to serve you. Read more about our powder coating pretreatment process and what separates Rhinehart Finishing from others in the industry. To learn more about what we can do for you or to request a quote, contact us today.
Frequently Asked Questions
What’s the difference between mechanical and chemical pretreatment?
Mechanical blasting uses abrasive media to create a desired texture on substrates. On the other hand, chemical pretreatment processes such as zinc phosphate are used to modify the metal’s surface chemically for better adhesion.
When is zinc phosphate preferred over other pretreatment methods?
Zinc phosphate pretreatment is used for applications such as high-corrosion environments, multi-metal assemblies and mil-spec coating systems where iron phosphate would not achieve the best results.
Can Rhinehart develop custom pretreatment sequences for unique applications?
Yes, we can offer custom pretreatment planning based on part geometry, performance specs and the customer’s specific industry. Just talk to one of our representatives to discuss your needs and we will develop a plan that’s right for you.
How does pretreatment impact coating warranty or mil-spec compliance?
Without the proper pretreatment and prep techniques, warranties may be voided and mil-spec audits may lead to rejections. Many certified finishing programs require proper phosphate coating prep, and Rhinehart Finishing is fully equipped to provide it.