1. Why Text May Blur (Initial Rusting Stage)
Cover the edges of engraved or painted text, blurring the boundary between text and the steel background.
Cause painted text to peel off if the paint is not compatible with the steel's oxidation process, leading to incomplete or fuzzy characters.
2. Text Processing Techniques to Prevent Blurring
Engraving/etching (Most Recommended)
Process: Carve text directly into the steel surface to a depth of 0.3–0.5 mm. The engraved grooves form a physical boundary that is not easily covered by surface rust.
Advantage: Once the patina matures, the engraved text will have a natural color contrast (darker in the grooves, lighter on the surface) due to differential oxidation, making it more distinct. The text is permanent and will not peel or fade.
Laser Marking
Process: Use a laser to melt the surface of the steel to form text, which changes the microstructure of the steel surface in the marked area, resulting in a color difference (e.g., dark gray text on reddish-brown patina).
Advantage: No protrusions or coatings, and the text is resistant to rust coverage. Suitable for fine text on small guide signs.
Stainless Steel Inlay
Process: Inlay stainless steel (304/316 grade) letters into pre-cut grooves on the weathering steel surface, and fix them with non-conductive gaskets to avoid galvanic corrosion.
Advantage: The stainless steel text does not rust, forming a clear contrast with the reddish-brown patina, and is permanently legible. Ideal for important guide signs with high visibility requirements.
High-Temperature Resistant Paint (Limited Use)
If using painted text, choose patina-compatible, breathable high-temperature resistant paint (avoid ordinary oil-based paint). The paint film is permeable, allowing the steel to form patina while protecting the text from being covered by loose rust.
Note: Reapply the paint every 3–5 years to maintain legibility.
3. Maintenance Measures to Keep Text Clear
Accelerate Patina Maturation: Use artificial patina acceleration before installing the sign, so the text is formed on a stable, dense patina surface, avoiding blurring caused by initial loose rust.
Regular Gentle Cleaning: Rinse the sign surface with fresh water every 2–3 months to remove dust and loose rust particles on the text. Do not use abrasive tools to scrub the text area.
Seal the Text Area: Apply a thin layer of transparent breathable sealant to the text and surrounding area after the patina matures. This locks in the patina structure and prevents rust from accumulating in the text grooves.
