Stop scrubbing. Start using the system that does the work for you.

Two-step washing is built for operators dealing with heavy grime, mineral staining and complex surfaces. Instead of relying on aggressive chemicals or manual effort, two-step washing changes how the job gets done.

This is a controlled cleaning system. It uses chemical reaction, application method, dwell time and correct setup to remove contamination at scale. When done right, it reduces labour, improves consistency and delivers a faster clean across every vehicle.

What is Two-Step Washing?

Standard washing relies on pressure and manual effort. Two-step washing relies on chemistry and control.

It uses two opposing pH chemicals applied in sequence to break down different contamination types:

Step 1 – Acid Wash (Low pH)
Breaks down mineral-based contamination like calcium, red dirt and road film.

Step 2 – Alkaline Detergent (High pH)
Lifts oils, grease and remaining organic grime.

This sequence allows each chemical to do its job properly. The result is a more complete clean without aggressive brushing or overuse of product.

Where it Delivers the Most Value

Two-step washing is built for heavy-duty environments where contamination builds fast and standard washing struggles.

You will see the strongest results on:

• Concrete agitators and equipment
• Water trucks with calcium staining
• Fleet vehicles exposed to red dirt and mineral deposits
• Garbage trucks, tippers, cranes and excavators
• Equipment with irregular shapes where brushes can’t reach

If the contamination is mineral-based, this system works.

Why Operators Move to a Two-Step System

The shift is not about cleaning differently. It is about improving output across the entire wash process.

Key gains:

• Reduced cleaning time across fleets
• Less manual brushing and labour
• Cleans into joints, seams and hard-to-reach areas
• Delivers consistent results across vehicles and operators
• Reduces risk of micro-scratching from brushing

How the Process Works

This is a controlled sequence. Each step matters.

1. Pre-wet the surface:  Always start with a wet surface. Acid on a dry surface increases risk of damage. As a rule, never apply acid to a dry surface.
2. Apply Acid Wash (Step 1): Apply using controlled spray or foam. Keep the surface wet. Do not allow the product to dry.
3. Apply Alkaline Detergent (Step 2): Apply over the top while the acid is still active. This drives the reaction and lifts remaining contamination.
4. Rinse Thoroughly: Use high pressure to remove all residues and leave a clean, consistent finish.
   
   

Following is a before and after example.

BEFORE: Built-up mineral staining, red dirt and grime that standard washing struggles to remove. [Scroll for after]

AFTER: Two-step washing cuts through contamination, delivering a clean satin finish without over-aggressive chemical impact.

Application Method Drives Results

How the chemical is applied directly affects how it behaves:

• Mist application → deeper penetration, more aggressive
• Foam application → increased dwell time, more controlled
• Flooding → less penetration, lower impact

Incorrect application can lead to inconsistent results or surface damage. Correct application delivers repeatable performance.

The System Matters More Than the Chemical

Two-step washing is not a basic setup.  Results depend on the full system working together.

To get the result safely and consistently, you need the following:

• High-pressure chemical injection system (e.g. ST160)
• Stainless steel injectors suited for acid application
• Correct nozzle and dilution setup
• A pressure cleaner matched to the application
• Operator understanding of surfaces and dwell time

The outcome is driven by the full system, not a single component.

Two Step Wash is a Trained Process

This is a trained process, not a general cleaning method. Because of the type of chemicals, surfaces and applications, it's important that operators understand:

• Surface types and sensitivity
• Chemical behaviour and dwell time
• Application techniques
• Rinse requirements

Correct use of the system delivers fast, repeatable results across fleets. 

Safety & Handing

This is a professional-use product. Incorrect use can cause surface damage or injury.

• Always wear appropriate PPE
• Always apply to a wet surface — never apply to dry surfaces
• Do not allow product to dry on surfaces
• Do not exceed recommended dwell time
• Always test on a small, inconspicuous area before full application
• Use correct dilution, equipment and application method
• Incorrect application (mist, foam or flood) can increase risk of damage
• Avoid use on hot surfaces or in direct sunlight
• Take care on aluminium, painted and sensitive surfaces
• Avoid uncontrolled runoff into the environment
• Carry calcium gluconate gel when handling acid-based products

Is Two-Step Washing Right for Your Operation?

This system is suited to operators who:

• Wash fleets regularly
• Deal with mineral-based contamination
• Want to reduce labour and cleaning time
• Are prepared to invest in proper setup and training

If you’re looking for a quick spot cleaner, this isn’t it. 
If you want a repeatable, scalable system that gets the job done properly, this is where it fits.

Recommended System Setup 

To get the best results, use the full FlowRPM system:

Step 1: FlowRPM Acid Wash & Brightener
Step 2: FlowRPM Touchless Fleet Wash
System: SPITWATER pressure cleaner with chemical injection setup

Optional:

• Foam system for increased dwell time
• Applicators for detailed cleaning