Rushton's DIY approach to ultrasonic record cleaning published by Positive Feedback

A friend pointed out this thread to me today.  Thanks for all of your contributions.  I will be making some adjustments to my cleaning solution mix.
I've been using a DIY ultrasonic cleaner for about two years now.  I use an 80 kHz Vibrato tank and turn three records through the bath at a 5 minute per rotation rate.  My record spacing is about 1 inch.  
Rushton's recommendation of a maximum bath temperature of 36 degrees Celsius accords exactly with my experience.  At higher temperatures (40 degrees plus), and while using a 60 kHz transducer, I did rarely experience some permanent vinyl deformation.
i agree also that regular tank filtration (1 micron filter) and periodic cleaning fluid replacement are essential to success.
in comparing the results of the 60 and 80 kHZ transducers, I found that the 80 hHz machine was the superior cleaner but that it required longer bath times.  The Vibrato machine I use has both a thermostatic control and a timer shut off.  Consequently, I don't hesitate to leave particularly dirty records (I buy many used ones) cycling for 35 or 40 minutes at a time.  
Given prolonged exposure, the finer cavitation bubbles of 80 kHz machine ultimately remove the dirt more effectively than the 60 kHz.  The finer cavitation bubbles and limited bath temperature allow extended safe exposure of the vinyl to the bath.  

Salvatore on 'highendaudio' has tried us record cleaning. He say to take care with maximum power.

@cedar

Thanks for sharing your experience! 

I've looked at the Vibrato tanks, and while much more expensive than the generic 40kHz machines like mine, they look to be designed and constructed at a significantly higher level.  And for an 80kHz machine, $675 is actually a very reasonable price based on other machines at that frequency.  Have you used the Vibrato for the whole 2 years since you started, and if so, how is it holding up?  Any issues or problems with it?

http://vibratollc.com/new-products.html

Thanks,
Bill

Cedar, thanks for contributing to the conversation! The more we share experiences, the more we each learn. And I really appreciate your contribution.

It is helpful to get some reports of actual experience comparing results with the different frequency tanks. That's not something most of us get an opportunity to do.

When you made your comparison with 60 vs. 80Khz tanks, how did you go about it?

It is so difficult to control for all the variables. I'm getting ready to experiment with 2" spacing in my 40Khz tank to see if the results are better than my current 1" spacing, but if I use an existing LP that was cleaned with the closer spacing, I know the first challenge will be controlling for the simple fact that the LP will now have been cleaned TWICE.

The VibratoLLC tanks have an excellent reputation. Louis is doing great work with his build quality from everything I read. I got an email reply from him yesterday that he will be announcing a new 80Khz ultrasonic tank WITH A DRAIN sometime after the first of the year. No pricing available yet, he says. I am very interested in seeing what he is able to offer.

Yes, I've used the Vibrato machines in my record cleaning systems.  I found Louis, at Vibrato, to be a very reliable guy.  
I was influenced initially by the work of a Texan who published his methods and materials on a different forum a few years ago.  He got me thinking about particle sizes and ultrasonic frequencies.  
I began with a 60 kHz Vibrato machine, which worked very well.  A number of factors led me to believe that longer, gentler cleaning was a more effective and safer approach.  So, I bought the 80 kHz machine.  While the cavitation bubbles of the 80 kHz machine are most effective at removing smaller particles, I found that if I ran the record for a longer time those smaller bubbles did remove larger particles as well as the 60 kHz system did.  Also, I experimented with timing motor speeds and the cleaning solution mix.  
My testing has been by ear.  I listen to a record and clean it until I am satisfied that it has stopped improving.  This listening test led me to conclude that the 80kHz machine would clean more effectively than the 60 kHz machine.
One downside of my approach is that record cleaning takes more time.  Since I enjoy the process that is not a burden for me.  
I use cork stoppers large enough to cover the record label between the records as I mount them on the spindle.  These cork rings are 1.25 inches thick.  I mount three LPs at a time, which leaves them approximately uniformly distributed between the tank walls in the bath.  I did not perceive improved listening results when I have increased the distance between LPs (2 LPs per cycle).  When I tried more than 3 LPs per cycle I did begin to see some impairment of the water circulation movement.  So, I've stayed with 3 LPs.