Hello everyone! Today, let’s talk about a crucial step in warehouse rack production—specifically, the degreasing and derusting process used in surface pretreatment. While this step may seem minor at first glance, it actually lays the "foundation" that determines whether your racks will stand the test of time and withstand the harsh conditions of a warehouse environment. If this step isn’t done properly, no amount of paint applied afterward will make a difference—just like building a house without a solid foundation: it might look sturdy on the surface, but once faced with wind or rain, its true weakness will quickly become apparent. Now, let’s dive deeper and explain exactly how we clean those metal frames!

1. Why is it necessary to remove oil and rust? Can't we just skip it?
 

Many people think, "Anyway, it’ll be painted in the end—so a little dirt doesn’t matter, right?" How wrong they are! Oil residues can stick to dust like glue, causing the paint surface to bubble and peel off. And rust is even more dangerous—it actually acts as an “accelerator of corrosion,” silently spreading beneath the coating. According to… China Logistics Equipment Quality Inspection Report 》Statistics show that the rework rate for shelves caused by inadequate surface treatment is as high as 37%, especially in warehouses located in humid regions, where extensive peeling and rusting can occur within just six months. Therefore, this step is not optional—it’s a must-do!

II. Practical Gameplay: A Comparison of Two Mainstream Oil- and Rust-Removal Solutions
 

Currently, there are two commonly used routes in the factory, each with its own unique approach:

✅ Option A: Physical Polishing + High-Pressure Water Washing (Suitable for Light Oil Stains)
First, use an angle grinder fitted with a wire brush to coarsely grind the weld seams and joints, effectively dislodging large rust flakes. Next, follow up with a high-pressure water gun—adjust the water pressure to 8–10 MPa (roughly equivalent to the pressure used at car washes for cleaning wheel hubs)—which can remove more than 90% of loose rust and oil stains. This method is low-cost and easy to perform; however, its drawback lies in its limited effectiveness when it comes to thoroughly cleaning hard-to-reach areas of complex structures. Additionally, after washing, the surface must be dried immediately—otherwise, secondary rusting is likely to occur.

✅ Option B: Chemical Soaking + Ultrasonic Assistance (for Stubborn Stains)
For steel that has been stored for a long time and is severely rusted, it’s time to bring out the "Bone-Dissolving Palm Technique"—the acid pickling bath. Simply immerse the workpiece in a diluted hydrochloric acid solution (typically around 5%–8% concentration), where a chemical reaction effectively dissolves the oxide layer. Nowadays, many advanced production lines even incorporate ultrasonic vibrations, essentially giving the metal a spa treatment—vibrations powerful enough to dislodge dirt even from the tiniest pores. However, it’s crucial to carefully control the soaking time; overdoing it can actually lead to corrosion of the base metal itself. According to real-world data from a major shelving manufacturer, steel treated with standardized acid pickling exhibits 40% higher adhesion compared to conventionally processed materials.

III. It's the easily overlooked details that truly demonstrate skill.
 

Experienced masters who often work with shelves all know this. “Three parts material, seven parts craftsmanship.” These key points directly influence the final outcome:

Temperature control is crucial: A note for those working in winter! When the workshop temperature drops below 5°C, the activity of the degreasing agent significantly decreases. Forcing operations under these conditions is simply a waste of time and effort. We recommend heating the bath solution to 25–35°C—about the same as the ideal water temperature for a relaxing bath—since this range ensures the fastest reaction rate.

The little secret of the phosphating film: True experts perform an extra phosphating step after rust removal, creating a dense crystalline structure on the metal surface. This invisible protective layer ensures that powder coatings adhere even more firmly—and it even doubles the duration of salt-spray tests! It’s just like applying a tempered glass screen protector to your phone, instantly boosting its drop-proof performance.

Don’t cut corners in the drying process: Whether washing with water or blow-drying, make sure the substrate is completely dry. There’s a real-life example—certain batches of shelving were sprayed before being fully dried due to tight deadlines—and three months later, widespread blistering appeared, ultimately driving up repair costs even further.

IV. A Guide to Avoiding Common Pitfalls for Beginners
 

"The Faster, the Better" Trap "Some workers, in an effort to meet deadlines, shortened the pickling time—only to find that the underlying rust was completely untouched. As a result, while the surface may appear shiny and attractive, it actually harbors hidden risks. The standard procedure requires that no new rust spots be visible to the naked eye for the process to be considered合格."

"One-size-fits-all" thinking : Never use random chemicals on stainless steel—please! Ordinary rust removers contain chloride ions, which can actually accelerate corrosion of the stainless steel. In such cases, only a specialized stainless steel cleaner should be used.

"The hindsight bias" phenomenon : Many quality issues only become apparent after installation. Smart manufacturers conduct the grid test before products leave the factory—using a utility knife to score a cross into the coating. If the coating can be peeled off easily with tape, it means the adhesion is substandard and the product will need to be reworked or remade entirely.

A good shelf starts with "washing your face."
    

Ultimately, degreasing and derusting are all about giving metal a thorough deep clean—and some serious beauty care. Don’t be fooled by how time-consuming and labor-intensive this process may seem; it’s precisely what determines the user experience your shelves will deliver over the next decade. Next time you visit the warehouse, take a moment to feel the column joints: they should feel smooth, perfectly flat, with no burrs or sharp edges, and absolutely no yellowish-brown rust seeping through. That’s a clear sign that solid surface pre-treatment has been meticulously carried out. After all, truly reliable products never overlook even the smallest detail!