Zinc and Zinc-Nickel Rack Plating
Rack plating is the best option for large parts, complex geometries, or parts with delicate features. Each piece is handled individually to protect critical surfaces and ensure more uniform coverage.
With the largest rack zinc plating line in the United States, we have ample capacity for all component types including fabrications & assemblies, heavy fasteners, long lengths of tube and large stampings.
Why Choose Gatto for Rack Plating
Our high-capacity rack plating lines are designed to move orders quickly and handle parts of all sizes, including large components that are not a fit for standard plating lines.
Real-Time Process Control
Our technicians monitor parts as they plate, making adjustments in real-time. This hands-on approach allows us to process complex shapes and movable components effectively, improving coverage, reducing rework, and producing consistent finishes across orders.
Custom Racking for Every Order
Each rack setup is configured for your part’s geometry and surface requirements. Careful positioning of contact points and orientation enhances current flow, limits shadowing, and helps ensure critical surfaces receive more uniform protection.
Measured and Verified Quality
Quality control starts with our in-house lab, where we monitor and maintain plating baths daily. All orders receive in-process quality checks to confirm coating thickness and overall quality. With more than 50 years of rack plating experience, we’re able to identify potential issues early and resolve them before they cause bigger problems.
Capacity That Keeps Schedules on Track
With multiple rack lines and large-scale tanks, we can handle substantial orders without extending lead times. Our throughput and process control help customers meet tight production schedules, even with oversized or complex parts.
Rack + Barrel Options Under One Roof
Because both rack and barrel lines operate in the same facility, we can select the most efficient, cost-effective process for your parts.
Why Our Rack Plating Process Matters
Rack plating results are directly influenced by part size, geometry, material type, and surface condition. Our experienced team considers these factors when setting up each job to ensure parts are positioned for optimal coverage.
To maximize quality and efficiency, our technicians focus on:
- Correct Part Orientation And Spacing for adequate current flow
- Optimal Rack Design for efficient processing
- Real-Time Adjustments During Processing to achieve more consistent results
Some variation is inherent in electroplating, but proper setup and active oversight help produce more predictable finishes.
As part of this process, our in-house tooling team is dedicated to building and maintaining our racking, allowing us to handle unique shapes, fix issues quickly, and run parts efficiently for faster turnaround.
What Is Rack Plating and How Does It Work?
Rack processing is used for parts that cannot be plated in bulk. Instead of tumbling together as they would in barrel plating, each part is handled individually and hung on customized fixtures designed to hold it securely and prevent contact with other components. This allows parts to be plated safely when they are:
- Too large or heavy for bulk plating
- Delicate or prone to damage
- Complex in shape or geometry
Because electroplating relies on current flow, each part must maintain access to the anode for proper coverage. Rack plating allows a wide range of part types to be positioned properly for a consistent coating.
Benefits of Rack Plating
- Handles A Wide Range of Part Types & Geometries - Designed for larger and heavier components that exceed typical barrel plating limits, accommodating a wider range of parts.
- Prevents Surface Damage And Part Tangling - Each part is individually secured, protecting threads, edges, and finished surfaces from scratching, denting, or interlocking during plating.
- Improved Coverage on Complex Shapes - Operators can adjust part orientation and spacing during rack plating to achieve more uniform coverage on all surfaces.
- Reduced Tangling and Defects - Parts can nest or tangle in barrel plating, causing bare spots and cosmetic flaws. Rack plating keeps parts separated to prevent these issues.
Rack vs. Barrel Plating
Gatto provides both rack and barrel processing, but your part’s size, geometry, and features will determine which method is most effective. The table below shows how the two processes compare.
| Rack Plating | Barrel Plating |
|---|---|
| Parts are individually secured to racks | Parts tumble freely in bulk inside a rotating barrel |
| Best for larger or heavier components: • Over ~7" • Or heavier than 1 lb. | Best for small, durable parts: • Under ~7" • And lighter than 1 lb. |
| Ideal for thin, fragile, or intricate parts that need individual handling | Ideal for durable fasteners, fittings, and hardware that can tumble safely |
| Prevents surface contact and abrasion | Parts contact each other during processing, which can deform delicate features. |
| Better control of part orientation allows for more uniform thickness and coverage | Tumbling will deburr and burnish surfaces which can provide a brighter appearance than rack plating |
| Parts require individual handling and longer set up times | Parts can be loaded and processed in bulk which improves cost and efficiency |
Choosing between rack and barrel plating depends on your part and performance requirements. We use our experience to help you choose the right process for your parts.
Rack Plating Limitations and What to Expect
Rack plating offers precision and control, but it also has its limitations. Understanding how current, contact, and part design influence plating deposit helps set realistic expectations for finish appearance and performance.
Rack Marks and Contact Points
Each part must make contact with a hook or fixture when secured to the rack, which can create small, visible rack marks. These marks are normal and generally acceptable, but Gatto uses multiple fixturing methods to reduce or eliminate them whenever possible.
How Gatto Minimizes Rack Marks:
- Use non-critical or hidden surfaces for contact when possible
- Reduce the size of the hook or fixture so that contact is minimal
- Create enough space between part surface and hook/fixture to eliminate bare spots
- When feasible, move parts in-process to cover rack marks
Current Distribution and Thickness Variation
Plating thickness varies with electroplating because different areas of a part receive different levels of current. High-current-density areas such as edges, protrusions, and surfaces closer to the anode, plate faster. Low-current-density areas, including recesses, corners, and holes, plate more slowly.
How Gatto Manages Current Distribution:
- Orient parts to shield high current areas and expose more of the low current features to the anode
- Reduce or increase the amount of parts on a rack to help even out the current flow to each part
- Utilize a custom rack, such as an auxiliary anode, to provide coverage on interior surfaces
Interior Features and Cavities
Deep recesses, corners, and interior surfaces often receive little to no plating compared to exterior areas because solution flow and electrical current are restricted inside these areas. Proper part orientation and rack configuration can greatly improve uniformity, but full internal coverage is not part of the standard plating process.
If full interior coverage is required, it can sometimes be achieved using an auxiliary anode. However, this must be specified upfront, as it’s not part of the standard plating process and requires additional setup, cost, and processing time.
Parts with enclosed or hollow sections may also require vent holes to allow solution flow and prevent trapped gases or plating bleed-out.
When To Consider Barrel Plating Instead of Rack Plating
Rack plating provides careful handling for larger or more delicate parts, but barrel plating is often the better choice when:
- Parts are small, durable and produced in large quantities
- Parts lack a contact point
- Parts do not require individual fixturing
Barrel plating is ideal for small, durable hardware and stampings of high volumes.
Rack Plating: Frequently Asked Questions
Rack plating is a type of processing where parts are secured individually on a hook or fixture. It is used for large, heavy parts and parts with critical features that cannot be damaged during plating.
Yes. Rack marks are small unplated spots where electrical contact is made between the rack and the part; though a quality plating process will minimize them, they’re normal and placed in non-critical areas whenever possible.
Not fully. Deep recesses, corners or enclosed areas may receive little to no plating coverage because electrical current doesn’t have direct access to those areas.
Yes, rack plating is generally more expensive than barrel plating. Each part is individually mounted and removed by hand, which increases labor and processing time. However, rack plating allows for careful handling that helps prevent damage and costly rework.
For best results, a hanging hole is ideal. Parts without holes can still be processed, but they require a longer, more complex rack configuration, and rack marks may be unavoidable.
Gatto offers rack processing in zinc, zinc-nickel, and aluminum chromate finishes.
Gatto can plate parts up to 27 feet long and 8,000 pounds on “King Kong”, one of the largest rack zinc plating lines in the U.S.!
Yes. Since each part is handled individually, rack plating works well for prototypes and low-volume parts that require careful handling. However, if a part will eventually be barrel plated, a rack-plated sample won’t represent barrel process results.
Send us your drawings or samples. Our team will determine whether rack or barrel plating is the best fit for your application.
Located in Chicago, we reach 65% of the U.S. in a day, lowering freight costs, reducing lead times, and enabling direct shipping to your customer.
With 210,000 sq. ft., we process full truckload orders efficiently, keeping parts organized and on schedule with dedicated staging, processing, and tracking.
Flaking, bleed-out, poor adhesion, we catch plating issues early before they turn into costly problems.
From fast quotes to clear answers, we simplify the plating process so you can focus on the rest of your project.
Contact Our Plating Experts
Whether you know exactly what you need or just need to talk it through, we’re here to help with quick turnaround times and expert guidance.