Humminguru Nova

@ljgerens

I think the generic US cleaners that you most likely used as a basis for your cleaner shoot the cavitation bubbles up. A purpose built machine has transducers facing the record surface. I’m sure you get your LPs cleaned but it’s just not as effective. 

@audphile1 

Yes, my ultrasonic cleaner had the transducers on the bottom. The cleaning efficiency for any contaminant examined was between 95 to 98% removal. Significantly better compared to other cleaning methods that we evaluated in my laboratory.

@ljgerens that’s great. What were the other methods?

Once I optimized my ultrasonic record cleaning setup and felt it produced excellent results, some of my colleagues were interested in comparing it with their record cleaning methods. The following record cleaning methods were evaluated.

1. Manually scrubbing with a brush using distilled water and dish soap followed by rinsing with distilled water.

2. Several passes with the original Spin-Clean record cleaner with the Spin-Clean solution followed by a distilled water rinse.

3. Several passes with an early VPI vacuum record cleaner using Harry Weisfield's recommended solution which consisted of distilled water, isopropyl alcohol and a non-ionic primary alcohol ethoxylate surfactant followed by a distilled water rinse.

4. My laboratory ultrasonic bath using distilled water and a non-ionic primary alcohol ethoxylate surfactant followed by a distilled water rinse.

For these experiments, we used newly purchased identical records which were initially played and evaluated for SQ to make sure they sounded similar. They were then cleaned by the different cleaning methods and evaluated again for SQ. The general consensus was that the ultrasonic cleaned record had the best SQ by a wide margin followed by the VPI and finally the Spin Clean and manually cleaned were indistinguishable.

The next part of this experiment was to use several different surface analysis techniques to determine the effectiveness of the various cleaning methods at removing known contaminants. 

A series of known contaminants (oils, greases, lubricants, hard water and finger prints) were applied to specific areas of each record. Controlled heat (~ 50 degrees C) was then applied to the records to drive off any solvents, simulate aging and induce interdiffusion and/or any chemical interaction which would make the contaminants more difficult to remove. The records were then cleaned with the various cleaning methods. The surface analysis of the contaminated areas requires cutting the areas into ~1 cm squares. These ~1 cm squares were then evaluated with several different surface analysis techniques. All of these cleaning methods removed significant amounts of surface contaminants but none produced a record with as clean a surface as ultrasonic cleaning. In all cases, ultrasonic cleaning removed significantly more surface contaminants than any of the other cleaning methods. Typically ultrasonic cleaning removed ~95 to 98% of all contaminants compared to ~50% to 80% with the other cleaning methods. The range depends on the specific contaminant and specific cleaning method. Some of the cleaning methods were less effective at removing certain contaminants.

The primary analytical techniques that were used to analyze these samples include: Photoelectron Spectroscopy (PES), Optical Microscopy, Thermal Desorption Mass Spectrometry (TDMS), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM).

That’s very cool @ljgerens and encouraging. I recently purchased a bunch of new records and played them without a wash. I’ll test them out after a wash in a Nova.