Ultrasonic Cleaning Solutions

How to Select the Best Ultrasonic Cleaning Solution

Selecting the right ultrasonic cleaning solution is the most critical factor for achieving successful results. Ultrasonic cleaning solutions—often referred to as ‘soaps’ or ‘formulas’—are highly specialized chemistries designed to tackle distinct cleaning challenges, from removing rust to dissolving heavy grease.

To properly select an ultrasonic cleaning solution, you must weigh two crucial considerations:

• the material of the product being cleaned, and
• the specific nature of the contaminant you need to remove.

This guide offers a comprehensive tutorial on the essential ultrasonic cleaning formulas—classified by both action (emulsifying vs. demulsifying) and pH (acidic, alkaline, or neutral)—to help you solve your cleaning challenges efficiently.

Understanding Ultrasonic Cleaner Chemistries – Emulsifying vs. Demulsifying & pH

Emulsifying vs. Demulsifying Formulas – Optimizing for Volume and Disposal

When emulsifying formulas are used, contaminants accumulate, lower cleaning effectiveness and the solution must be replaced. Contaminants can adhere to products being removed from the cleaning tank.  This may call for a post-cleaning rinse.  Emulsifying formulations are typically used for low-volume cleaning operations.

Demulsifying formulas are favored for high-volume cleaning where oily contaminants float to the surface.  For benchtop cleaners, contaminants are skimmed off manually and set aside for disposal.  Large-capacity tanks equipped with skimmers direct contaminants to a storage tank.  These units also may be equipped with filters to trap hard contaminants.

Tips for extending the life of ultrasonic cleaning chemistries are found in extending ultrasonic cleaning solution performance.

The Importance of pH – Choosing Acidic, Alkaline, and Neutral Ultrasonic Formulas

Acidic cleaners are often used to remove rust, lime, oxide films, grease and oil from nonferrous metals.

Emulsifying, mildly acidic Elma tec clean S1 removes oxide films, rust, lime, grease, oil, corrosion, and mineral deposits.   It is recommended for electronic parts, copper and brass decorative items, removing hard water films, cleaning lab sieves, removing lime and calcium from plumbing fixtures, and for restoring tools.

Stronger acidic solutions are available for these materials along with steel, iron, gray cast iron, hard alloys, nickel, nonferrous heavy metals and precious metals.  We suggest using elma-KS for temporary corrosion protection for steel and iron during cleaning and rinsing cycles.

Note that strong inorganic acids should be used in an acid resistant tub (offered in several sizes) along with other precautions to follow for safely cleaning with acid. 

A mildly alkaline solution is our best-selling ultrasonic cleaning formula – emulsifying Elma tec clean A1.  Use it to remove water damage, water-soluble flux, oil, grease, fingerprints, dust, and other contaminants from PCBs, mother boards, electronic parts, fine optics and plastics.  It is easily and thoroughly rinsed with water.

Another alkaline example is demulsifying Elma tec clean A4, the “universal cleaner” widely used to remove oil, grease, soot, coking, forge, dust and finger prints.  It is recommended for engine parts, gears, bearings, carburetors, fuel injectors, filters and screens, newly machined metal parts, plastic parts and sport and recreation power equipment.

A neutral formulation is demulsifying foam-inhibited Elma Lab Clean N10 to remove oil, grease and other organic particles from sensitive or delicate pieces such as lab instruments and labware made of metal, plastic, glass and ceramics.

A pH Formula Comparison Table

This table summarizes the core differences in pH value, primary use case, and common contaminants removed by the three main classes of ultrasonic cleaning solutions.

Specialized Ultrasonic Solutions for Medical, Firearms, and Jewelry Cleaning

Cleaning Medical and Surgical Instruments

Enzymatic concentrate MedClean C7 is used  to clean medical, dental and surgical instruments.  Use it to remove blood, tissue, ointments, light oils and similar contaminants before disinfecting or sterilizing.

Cleaning Firearms

For firearm cleaning use GunClean L6  to remove  powder residue, bullet shavings, hardened lubricants and other contaminants much faster and more thoroughly than with brushes or solvents.

After cleaning, the firearm can be fully lubricated in a bath of GunLube L5 ultrasonic gun lubricant for protection against rusting.

Check ultrasonic cleaners for firearms to see how ultrasonic cleaning equipment helps public safety and military organizations, hunting and skeet shooting clubs as well as firearm collectors maintain performance of their pistols and rifles.

Jewelry Manufacturing

Removing dirt, grease, buffing compounds, rouge, tripoli and oxides from silver, platinum, jewelry and gems is accomplished in a bath in JewelryClean S8.  Note that softer jewels such as pearls should not be cleaned ultrasonically.

Safety First! Ultrasonic Cleaning with Flammable Solvents

Conventional ultrasonic cleaners should never be filled with flammable solvents.  Cleaning with flammable solvents such as acetone, toluene and IPA requires extra special precautions because they can create what is known by the National Fire Protection Association as a Hazardous Location.  You must also comply with your company and local public safety regulations.

Here are three options when cleaning with volatile solvents.

The first, using flammable solvent cleaning kits offered in three sizes, parts are immersed in a beaker containing the solvent.  The beaker is lightly covered and placed into the ultrasonic tank filled with water and a surfactant.

The second option is cleaning extremely small parts such as watch parts, small optical lense, and micro-machined parts in the explosion proof Elmasolvex VA ultrasonic cleaner.

When cleaning large parts, explosion proof ultrasonic cleaners are required that comply with national and local regulations.  If your requirements call for large scale cleaning using flammable solvents, contact us for information on the SOL XP explosion-proof ultrasonic cleaners.

Next Steps – Resources and Expert Recommendations on Ultrasonic Cleaner Solutions

We hope this information proves helpful as you navigate the many ultrasonic cleaning formulas available.

Useful information is also found in instructions manufacturers provide on the use of their products.  Details include dilution, recommended cleaning temperatures, and what are called safety data sheets (SDS) providing chemistry, handling and disposal procedures.

For additional information including unbiased recommendations on ultrasonic cleaning equipment, cleaning solution formulations and cleaning procedures, please contact the professionals at Tovatech, We are Elma’s North American distribution partner.