How to Clean Complex Parts in an Ultrasonic Parts Cleaner

An ultrasonic cleaner is widely recognized as an excellent tool to thoroughly clean assemblies and parts ranging from watches to internal combustion engine blocks.  Imploding microscopic bubbles in the ultrasonic cleaning solution are created by ultrasonic transducers and reach into minute cracks and crevices.  Using the power of cavitation they safely remove virtually all contaminants such as dried lubricants, rust, scale and varnishes.

For many parts, proper positioning is required to assure cavitation action reaches all surfaces.  Blind holes can be an impediment to this.  An example is machined screw slots that do not pass through the part, but instead can serve as a “well,” trapping air that effectively blocks the cleaning solution, meaning that contaminants remain.  The smaller the hole the more difficult it is to fill with solution.

Such parts should be placed carefully in the ultrasonic cleaning basket so that the holes are in a horizontal position and can fill as the basket is lowered into the cleaning tank.  If blind holes occur on several surfaces, the parts should be agitated in the basket so that all holes are filled with solution.  It may be necessary to manually maneuver the parts before the ultrasonic cleaner is turned on to assure all holes are filled with solution.  In extreme instances, operators may have to stop the cavitation action and further reposition parts in the basket then restart the cleaning cycle.

At the end of the cleaning cycle operators should position the basket and parts above the bath and allow cleaning solution to drain from these holes.  Otherwise cleaning solution will be dragged into the rinse tank, wasting solution and reducing the effectiveness of the rinse cycle.

Small-diameter tubing also poses cleaning challenges because cavitation action has to reach internal surfaces.   In one application the challenge was solved for cleaning precision tubes used in the manufacture of instruments designed to place implants.  This was accomplished by placing the tubes in a near vertical position and using the vertical oscillation feature of the Elma Flex Line ultrasonic cleaner and rinse tank.

In summary, position is important when complex parts are placed in an ultrasonic cleaner.  Air trapped in blind holes and crevices blocks ultrasonic cavitation and must be replaced with cleaning solution before the cycle begins.  Care should be taken to thoroughly drain these parts before they are placed in a rinse tank.  Please contact us for help if you are experiencing problems in cleaning complex parts.


How do you clean complex-shaped parts?  Please describe novel procedures you have developed.

About Bob Sandor

Bob began working as a chemist in 1987 and remains a science geek to this day. After his PhD he worked on the bench in materials and inorganic chemistry for 10 years. He then took on a love for marketing and sales. He combined his passion for science and business and took entrepreneur general management positions in large corporations like Hoecsht Celanese now Sanofi Aventis, Bel-Art and Smiths Detection. There he learned what it would take to run a business and finally Tovatech was co-founded in 2006. Bob’s hobbies include playing, listening and composing music, skiing, working out, the internet and all things science. Read More