Tea staining is a surface discolouration of stainless steel caused by chloride exposure, commonly found in coastal areas or where saline water is present.

While it can affect appearance, it is important to note:
Tea staining is not structural corrosion and does not impact the integrity or lifespan of the enclosure

Tea staining is typically influenced by:

• Chloride exposure (coastal environments, salt water, washdown water)
• Surface finish (rougher surfaces are more prone)
• Salt build-up and evaporation cycles
• Humidity and temperature
• Intermittent wetting (e.g. sea spray)

Salt deposits build up over time and become more concentrated as water evaporates, increasing the risk of staining.

1. Material Selection

• Use 316 stainless steel or higher for coastal or high-chloride environments
• 316 provides improved resistance due to added molybdenum

2. Surface Finish

• Smoother finishes perform better
• Recommended: No.4 finish (Ra ≤ 0.4 µm)

3. Regular Cleaning

• Wash regularly with fresh, clean water
• Removes salt deposits before they concentrate

4. Protective Coatings (if required)

• Clean surface thoroughly before applying
• Remove staining using a suitable cleaner (e.g. mild phosphoric-based solution)
• Apply a clear protective coating for added resistance in severe environments

Stainless steel is highly durable, but like any material exposed to harsh environments, it benefits from correct specification and routine maintenance.

With the right approach, your enclosure will maintain both its appearance and long-term performance.