Introduction
What is the greatest enemy of material management at construction and manufacturing sites in Vietnam? It is the invisible “humidity.” Especially during the rainy season (around May to October), humidity exceeds 80% daily, creating an extremely harsh environment for metal products.
“Aluminum doesn’t rust, so it’s fine”—thinking this, are you leaving expensive aluminum ladders and stepladders outdoors? Actually, that is a big misconception. Under specific conditions, aluminum also undergoes corrosion called “white rust (hydrated oxide).” Especially in high-temperature, high-humidity environments like Vietnam, within just a few months of purchase, the surface can turn white as if covered in powder, and in worst cases, there is a risk of moving parts seizing or strength degrading.
In this article, Hasegawa Vietnam will scientifically explain “why aluminum corrodes in Vietnam” from a professional perspective, and teach specific maintenance techniques to extend equipment life and protect site safety. Let’s protect your site’s “safety assets” with correct knowledge based on JIS standards (Japanese Industrial Standards).
Why Does Aluminum Corrode in Vietnam? The Scientific Mechanism
Vietnam’s Harsh Climate Data
One of the most important indicators in metal corrosion is “Critical Relative Humidity (CRH).” Generally, research shows that the corrosion rate of aluminum accelerates rapidly when relative humidity exceeds 65-75%.
Meanwhile, let’s look at climate data for Ho Chi Minh City in southern Vietnam and Hanoi in the north. The monthly average humidity in Ho Chi Minh City is about 70% even in the dry season, and reaches over 85% in the rainy season. In other words, under Vietnam’s environmental conditions, it can be said that we are almost constantly in the “danger zone” throughout the year where aluminum corrosion progresses easily.
Furthermore, in coastal regions like Da Nang and Hai Phong, winds containing salt (chloride ions) from the sea blow in. When moisture combines with salt, it becomes a powerful electrolyte solution, and the speed at which it destroys the protective film on the aluminum surface jumps to several times that of inland areas.
The True Nature and Risks of “White Rust”
The surface of aluminum is usually covered with a thin, dense “oxide film (Al₂O₃),” which acts as a barrier protecting the interior. However, if moisture continues to adhere for a long time in a high-temperature, high-humidity environment, this film undergoes a chemical reaction and changes into “aluminum hydroxide (Al(OH)₃)” and the like. This is the true identity of the white powdery substance seen on the surface, “white rust.”
White rust itself has some self-protective effect that suppresses further corrosion progress, but it should not be left untreated. This is because there are the following risks.
- Malfunction: If white rust clogs the telescopic parts of ladders or the opening/closing fittings (around rivets) of stepladders, movement becomes stiff, causing breakage due to forced operation.
- Contamination: It stains workers’ gloves and clothes, and even wallpaper at interior construction sites, white.
- Loss of Reliability: To the eyes of customers and clients, it appears as “dirty tools that are not well-managed,” damaging your trust as a professional.
Do It Now! Pro-Recommended Maintenance Routine
We will introduce three steps to practice on-site to reduce the cost of replacing expensive equipment and maintain safety.
1. Daily Cleaning: The Basics are “Wiping Off”
The most effective yet most overlooked step is “dry wiping after use.”
- Removal of Mud and Dust: Mud and mortar often contain moisture and salt, and leaving them attached causes localized corrosion (pitting). Be sure to remove them with a brush or rag after work.
- Precautions for Water Washing: Water washing is effective if the dirt is severe, but be sure to use a neutral detergent (diluted dishwashing detergent). Acidic or alkaline detergents are strictly prohibited as they dissolve the aluminum protective film (anodized aluminum).
- Complete Drying: After washing with water, wipe off moisture completely with a dry cloth and let it dry in a well-ventilated place. In the case of telescopic ladders, special care must be taken so that water does not remain inside the pipes.
2. Improving Storage Environment: Don’t Trap Moisture
Are you wrapping ladders tightly in blue tarps for storage, thinking “so they don’t get wet in the rain”? Actually, this can be counterproductive.
- Ensuring Breathability: If sealed with a sheet, moisture from the ground gets trapped inside, and “condensation” occurs due to the temperature difference between day and night. This becomes a hotbed for white rust. When storing, use a breathable cover, or store it in a well-ventilated place away from direct rain, such as under eaves, by leaning it away from the wall or storing it horizontally on a rack.
- Keep off the Ground: Placing it directly on soil ground will wick up moisture. Place it on duckboards or pallets to ensure airflow paths.
3. How to Deal with Existing White Rust
Even if white rust has occurred, recovery is possible if it is mild.
- Removal: Use a commercially available nylon non-woven fabric (such as Scotch-Brite) with “fine” or “ultra-fine” grade to gently polish off the rust. Avoid wire brushes as they damage the aluminum base metal.
- Protection: The oxide film is thin in areas where white rust has been removed. You can delay recurrence by applying a thin coat of commercially available clear lacquer or anti-rust spray. However, never paint the rungs (steps) as they will become slippery.
Why Hasegawa Quality is Strong Against “Humidity”
Cheap aluminum products flood the market, but why do pros choose Hasegawa? The secret lies in “invisible surface treatment” and “rigorous testing.”
Thorough Surface Treatment and Quality Control
Many of Hasegawa’s ladders and stepladders undergo high-quality “anodizing treatment (anodic oxide coating)” based on JIS standards (JIS H 8601). This process electrically generates a thick oxide film on the aluminum surface, dramatically improving corrosion resistance and wear resistance.
In cheap products, this film may be thin or the sealing treatment (the process of closing microscopic pores in the film) may be insufficient, but Hasegawa products are manufactured under strict quality control with specifications that can withstand Vietnam’s harsh climate. In particular, the black type of the “Ashigaru” series enhances not only design but also weather resistance through special painting and treatment.
Design Philosophy Supporting “Reliability You Feel When You Step On It”
Hasegawa Kogyo owns testing centers in the Da Nang factory in Vietnam, in addition to Japan and China, making it one of the company’s four major testing hubs globally. Here, we not only clear JIS and SG Mark standards but also conduct rigorous in-house tests over 250 times a month.
For example, we conduct corrosion tests assuming environments with high humidity and salt concentration, and repeated ascending/descending load tests of over 100,000 cycles, verifying the durability of every single rivet. Products manufactured at the Da Nang factory in Vietnam embody the very quality standards forged by demanding Japanese professional users, and are designed to minimize deterioration due to humidity.
Summary
Vietnam’s high-temperature, high-humidity environment is by no means kind to aluminum products. However, with the proper knowledge and maintenance, you can significantly extend the lifespan of your equipment.
- Know the Risks of Humidity: Understand that corrosion risk increases when humidity is above 65%.
- The Basics are “Wiping Off”: Do not leave moisture and dirt after use.
- Storage is about “Breathability”: Do not seal tightly; ensure good ventilation.
- Choose Reliable Products: Select Hasegawa products where anodizing treatment and quality control are thorough.
Maintenance is not just cleaning. It is a “safety investment” to prevent accidents at the site and protect the lives of workers. Review your site routine starting today and treat them with care as professional tools.
If you are concerned about the deterioration status of the equipment you are currently using, we recommend checking the latest models with excellent durability (such as BLACK LABEL and Ashigaru series) in the catalog.