HD-S1 Heavy Duty Step One – Industrial Acid Pre-Soak & Inorganic Soil Remover

**Overview**  
HD-S1 Heavy Duty Step One is a powerful acid-based pre-soak engineered to dissolve severe inorganic buildup, oxidation, mineral deposits, and bonded road film on industrial fleets and heavily used equipment. This is the first stage in the heavy-duty two-step washing process and is designed for maximum cleaning power.

**Key Benefits**  
- Aggressive cleaning action for severe inorganic soils and oxidation  
- Breaks down bonded film, mineral deposits, and weathered buildup  
- Prepares surfaces for the Step Two alkaline wash  
- Helps restore dull or neglected fleet surfaces  
- Performs extremely well with pressure washers and hot water units  
- Designed for industrial, commercial, and municipal fleets  

**Dilution Instructions**  
- General cleaning: 50 mL per 4 L  
- Normal soil: 100 mL per 4 L  
- Heavy soil: 200 mL per 4 L  
- Severe inorganic buildup: 500 mL per 4 L  

**Application / Use**  
1. Apply bottom-to-top or evenly across all surfaces.  
2. Do not allow the product to dry on the surface.  
3. Follow immediately with HD-S2 Heavy Duty Step Two while the surface is still wet.  
4. Rinse thoroughly using a pressure washer.

**Ideal For**  
- Construction trucks and industrial equipment  
- Waste vehicles and municipal fleets  
- Tankers, transport trucks, and high-mileage units  
- Equipment with heavy oxidation and neglected finishes  
- Operations requiring strong restoration power  

**Professional Use Warning**  
HD-S1 is an acid-based industrial cleaner for trained professionals only.  
Avoid polished metals, chrome, or sensitive surfaces. Always wear proper PPE.

**Safety & SDS**  
Use appropriate PPE when handling chemical products. SDS documents are available in our library.