Cleaning SPA‑H weathering steel signs must be gentle and non‑corrosive to avoid damaging the patina and causing uneven color. Here's the safe, standard method:
1. Daily / Routine cleaning (most common)
Use only clean water and a soft cloth, sponge, or soft brush.
Gently wipe or rinse to remove dust, bird droppings, and floating dirt.
Air dry naturally or wipe dry with a clean soft cloth.
Do not use hard brushes or high-pressure water jets that can scratch the patina.
2. For stubborn dirt (oil stains, mud marks)
Mix mild neutral detergent (dish soap is best) with water.
Wipe lightly with a soft cloth.
Immediately rinse thoroughly with clean water to remove all detergent residue.
Dry the surface.
3. For water stains / light rust streaks
Wipe with a dilute acetic acid solution (white vinegar + water) or very mild rust converter.
Quickly rinse with plenty of clean water.
Dry and reapply a thin layer of transparent protective oil if needed.
4. What to strictly avoid
Do not use strong acid or alkali cleaners (rust remover, bleach, caustic soda).
Do not use steel wool, hard brushes, sandpaper for daily cleaning.
Do not scrub violently, which will damage the patina and cause color unevenness.
