Key Takeaways

• Solution chemistry is specified based on what is being cleaned and what contaminants are present
• Most solutions today are biodegradable, non-toxic, and highly concentrated
• Alkaline, acidic, and neutral solutions serve different cleaning purposes
• Specialized solutions exist for optics, medical instruments, and weapons cleaning
• Always follow solution manufacturer instructions for dilution, temperature, and safety

Why Solution Chemistry Matters

Ultrasonic energy provides the physical action to remove contamination, but the solution chemistry determines what types of contaminants are dissolved or emulsified. The right solution helps cavitation bubbles penetrate and remove specific soils more effectively.

Using the wrong solution can result in:

• Poor cleaning performance
• Damage to part materials or finishes
• Solution breakdown or poor shelf life
• Safety or environmental concerns

Three Main Solution Families

Alkaline Solutions

• Best for: Oil, grease, machining coolants, and heavy contamination
• Chemistry: Higher pH (typically 9–13) breaks down oily soils
• Applications: Industrial parts, machinery, tools, engines
• Advantage: Aggressive cleaning for heavy soils
• Caution: Can attack some soft metals or delicate coatings

Acidic Solutions

• Best for: Rust, scale, mineral deposits, and oxidation
• Chemistry: Lower pH (typically 2–6) dissolves mineral and corrosion
• Applications: Metal parts, sensors, electronics after storage
• Advantage: Excellent for removing rust and scale
• Caution: Aggressive to some metals; requires careful part selection

Neutral Solutions

• Best for: General purpose cleaning, delicate parts, mixed applications
• Chemistry: pH near 7; gentle on materials while effective on soils
• Applications: Medical instruments, jewelry, optics, electronics
• Advantage: Safe for most materials, biodegradable, non-toxic
• Caution: May not be aggressive enough for heavy oils or rust

Specialized Solutions

Beyond the three main families, specialized solutions exist for specific applications:

Optics and Ophthalmic

• Formulated to clean lenses, glasses, and optical instruments without damage
• Non-corrosive to coatings and anti-reflective materials

Medical and Surgical Instruments

• Designed for blood, biological tissue, and bioburden removal
• Often combined with enzymatic action for protein breakdown
• Typically pH-neutral or slightly alkaline

Precision Weapons and Military

• Heavy-duty removal of cosmoline and protective coatings
• Leaves minimal residue

Flammable Solvent Solutions

• For parts contaminated with flammable oils or residues
• Requires an explosion-proof ultrasonic cleaner

Solution Concentration and Dilution

Most commercial cleaning solutions are highly concentrated. Never use a solution "straight from the bottle." Always:

• Follow the manufacturer's dilution ratio (typically 1:5 to 1:20)
• Use the correct type of water (deionized water is best)
• Mix thoroughly before use
• Allow proper conditioning time if required (consult the label)

Temperature Considerations

Most cleaning solutions work better with slight heating, but not all:

Heated Cleaning (80°C / 180°F)

• Improves cleaning of oils, grease, and heavy contamination
• Many solutions are formulated to work at elevated temperatures

Unheated Cleaning

• Recommended for biological contamination (blood, tissue)
• Higher temperatures stop cavitation; excessive heat can damage solutions

Always consult the solution instructions for recommended temperature ranges.