Ultrasonic Cleaning

In recent years ultrasonic cleaning has become the standard for final cleaning engine and transmission parts in the automotive, powersports, marine and aircraft industries. Ultrasonic cleaners use high-frequency sound pulses (above the range of human hearing) to agitate liquid cleaning detergents that gently clean and remove dirt and contaminants without requiring any harsh scrubbing, abrasion or high-pressure sprays. The use of ultrasonics in immersion cleaning technologies has become increasing popular due to restrictions placed on solvent-based vapor degreasing products.

The beauty of ultrasonic cleaning is that it is strong enough to remove hard contaminants yet gentle enough not to damage the substratum. Moreover, it is versatile in that it can remove a wide variety of contaminants, including grease, oil, cutting oils, buffing compounds, dirt, carbon deposits, oxidation, mold, bacteria and more, all the way down to down to a microscopic particle size.

Ultrasonic cleaning combines the use of an immersion tank, electrical power and chemistry to create a process of cavitation that generates millions of microscopic bubbles every second. As the bubbles grow in size due to alternating positive and negative pressure waves, they eventually implode, sending a high velocity jet speeding toward a component’s surface. The jet’s combined high pressure, temperature and velocity dislodge contaminants adhered to the component. Because of the jet’s minute size and its high energy, ultrasonics has the ability to reach intricate and hard-to-reach areas such as hidden passageways, oil galleys, blind holes, cracks, crevices and small apertures because the environmentally friendly citrus-water-based detergent and high-frequency ultrasonic waves penetrate all surfaces.

Since parts cleaning can be chemistry specific, the key to proper ultrasonic cleaning is getting the chemistry correct (pH level, temperature, and electrical power level). For starters, keeping the pH level of the liquid solution correct is critical. The pH scale ranges from 14 to 0, with 14 being alkaline, 0 being acidic, and 7 neutral. Some soft metals like aluminum can be damaged by high pH (high alkaline) solutions. Harder metals such as steels and stainless steels can handle a high pH solution. Conversely, metals with lots of rust and calcium buildup may require a low pH (acidic) solution, while neutral cleaning solutions work well with components having light surface contamination.

Temperature also plays an important part in ultrasonic cleaning. Too hot or too cold of solution can damage parts, cause poor cleaning, or stain (spider webs) parts. Most ultrasonic cleaning processes work best with a solution kept between the 135 F and 150 F temperature range because that range results in effective microscopic cleaning.

The optimum electrical power level (ultrasonic watt density) is also critical to proper ultrasonic cleaning. The ideal power level is a function of watt density, liquid volume and component metal alloy. Normally, less contaminated and lighter weight parts require less power because less energy is absorbed by the part. Additionally, smaller tanks require greater power than larger tanks. Other factors also come into play such as the frequency output (e.g., 40 kHz or 40,000 cycles per second). Advanced Tec-Neeks Super Finishing has over 15 years experience in the ultrasonic cleaning business and can rely on its vast experience for setting the ultrasonic variables correctly for the optimum chemistry.

Commonly used on steel, aluminum, brass, bronze and precious metals, ultrasonic cleaners thoroughly and effectively clean common engine parts such as carburetors, manifolds, cylinder heads, cylinders, valvetrain, transmission and drivetrain parts, and more. The ultrasonic cleaning process is also perfect for inboard and outboard marine motors with aluminum parts where gentle cleaning reduces the risk of future corrosion.

Ultrasonic Cleaning Benefits

  • Can remove contaminants quickly
  • Gentle cleaning without abrasion, harsh scrubbing or high pressure
  • More efficient than hand cleaning
  • Has the ability to reach intricate and hard-to-reach areas
  • Thorough, uniform cleaning
  • Excellent at removing mold and bacteria

Ultrasonic Cleaning Applications

  • Engine parts – carburetors, manifolds, cylinder heads, cylinders, valvetrain
  • Transmission and drivetrain parts
  • Final cleaning for other finishing processes such as vapor blasting and Isotropic Super Finishing

Ultrasonic Cleaning FAQs

What is an ultrasonic cleaner?

An ultrasonic cleaner is a cleaner that uses ultrasonic (high frequency)sound waves to clean objects. The frequency is above the human hearing range.

What causes “spider web” or “vein” witness marks on parts cleaned by ultrasonic cleaning?

Incorrect chemistry of the pH, temperature or watt density is usually the cause. At ATSF, we manage the ultrasonic chemistry to eliminate such problems.