Best Practices for Using an Ultrasonic Cleaner

Whether you’re restoring a classic car or repairing an old workhorse, an ultrasonic cleaner can be invaluable for cleaning and revitalizing small metal parts and delicate components. These clean machines use high-frequency sound waves in a liquid bath to dislodge contaminants. They’re often more effective than manual methods and allow you to work on other tasks while they clean.

While using an ultrasonic cleaner doesn’t require any special skills, your results will only be as good as your inputs. Here are some proper uses and considerations for incorporating an ultrasonic cleaner into your restoration workflow.

Cleaning Solution

The range of parts and materials that can be cleaned in an ultrasonic tank is impressive. You can clean everything from metal to plastic and even some electronics. Choosing the right cleaning solution for your parts is a critical first decision.

From water-soluble detergents to strong solvents, there are specialized formulas for removing carbon, grease, varnish, or rust. Always verify that your solution is safe for the materials you are cleaning and for the ultrasonic unit itself. And make sure you have a plan to properly dispose of used solution before you even start.

Pre-Clean or Degrease When Necessary

Ultrasonic cleaning is intended to remove fine contamination from delicate surfaces. They’re not designed for heavy deposits or grease, which can contaminate the bath quickly. A quick pre-wash or wipe-down helps keep your solution cleaner and more effective. On greasy engine and chassis parts, scrape or use a wire brush to remove caked-on debris first.

Use Heat and Degassing

Many ultrasonic cleaners have a built-in heater to improve cleaning effectiveness. The right temperature will depend on the material your cleaning and the solution being used. While hotter might seem better, keep in mind you’ll need to be able to handle whatever you remove from the tank.

“Degassing” removes air bubbles in the solution to ensure better cavitation and cleaning action. This function works well on parts with small opening or passages, where air may prevent the flow of cleaning solution.

Monitor Cleaning Times

While ultrasonic cleaning is generally safe, extended cleaning times can lead to damage. Too long a cycle risks etching or dulling finishes, especially on softer metals or delicate surfaces. It’s better to work in several short cycles, inspecting and even turning your work periodically, rather than one long stint.

Rinse and Dry Immediately

After cleaning, rinse with clean water (or an appropriate solvent) and dry all parts thoroughly (compressed air is often used). This step is critical to preventing flash rust or streaking caused by cleaner or residue drying on the warm components. When using a water-based cleaning solution

Maintain the Ultrasonic Unit

Make a habit of changing or filtering your cleaning solution once it becomes visibly dirty. Sediment or particles in the bath can reduce cleaning efficiency or re-deposit on parts. Periodically drain the tank entirely to remove the sludge that will inevitably settle on the bottom. Solvents can often be filtered and reused, while water-based solutions can usually be rinsed down a drain. Always check your local ordinances before disposing of any used cleaning solution.

An ultrasonic cleaner can be a powerful tool that makes labor-intensive cleaning tasks more efficient and thorough. By selecting compatible cleaning solutions, using proper cycle times, and paying close attention to materials and finishes, you can achieve excellent results with less manual labor and more consistent outcomes than traditional methods.