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

Fantastic! Good for you. The DIY approach takes us back to the roots of the hobby. Being able to share what you have learned, via the Net, makes your efforts valuable to a far larger group of people than in the "good old days" when information was shared via clubs or newsletters. 

Isn't there a math formula for calculating bath size, number and frequency of US transducers and surface area to be "cleaned"? 
I agree that multiple methods seem to work synergistically.  And in exploring the industrial side of US cleaning (not vinyl) I've been told that the use of a surfactant/detergent hugely improves ultrasonic cleaning results. I'm pretty agnostic on the machines themselves- had the AD, have the KL and rely heavily on the Monks. The real bonus to Rush's approach is that you can, ideally get all three: good, cheap and fast. 
May your records always be clean (and unwarped)!

bill hart

Isn't the point of rotating the disc in the US cleaner to even out the effect of the standing waves? 

Thanks, both. (Rush and Oilman). I have a local contact for Elma, which is on my shortlist. Oil- I have been wading through that DIY thread for a while. Lot's to digest.
best,
bill hart

Oilman-makes sense to me. What US unit are you using? I had mentioned in another thread that having field replaceable parts would make great sense. Your 'foil test' seems to be one some manufacturers themselves use, which led me to wonder whether there is a purpose built instrument used to measure cavitation intensity. I was in discussion with a manufacturer of large industrial US systems for parts (not vinyl), who was a very solid source of information, but he would not/could not make a custom built machine for me. (I have had both "audiophile" units and like Rush, am interested in optimized performance, rather than simply a cost-effective alternative to those). This seems to be something of a dark art. The DIY/crowd-sourced information is invaluable. 

The advantages of Rush’s approach are manifold: you can control heat, degas, filter using an external reservoir (which the newish KL does), use a surfactant and change the frequency if you opt for models offering such features. (Elma, for example). You are still in under the cost of most of the commercial US designed for LPs (save, perhaps, the V-8, which is a commercialized DIY type set up).
My best results come from pre-cleaning using AIVS No. 15, vacuuming using a point nozzle (Monks, but the Loricraft is essentially the same concept), rinsing using reagent grade 1 water and then running the record through the US. I had the AD, currently have a KL and when that goes, will go DIY-- I can use a surfactant, and do a reagent water rinse and vac dry on the Monks. My experience with these things tells me that the added step of vacuuming using point nozzle gets more of the contaminants out of the grooves than air drying, forced or passive.

I don’t go to these lengths on every record, but some of the older obscure/rare records aren’t always pristine, even at higher prices. Those really benefit from the pre-cleaning, and the post US vacuum on the point nozzle. There is no static or contamination issue using the Monks. (I have multiple mats, a wet and ’dry’ one). I’ve managed to get many records with wispy tracing distortion, and some which sound like the grooves have been damaged, to a very high state of play using these combined methods.
My work flow, while it sounds time consuming, is fairly efficient with both types of machines running simultaneously.
If a record looks pristine, I’ll give it a milder pre-clean on the Monks using the Hannl fluid (which @Syntax turned me on to a few years ago), a pure water rinse and then into the KL.
I’ve also changed inner sleeves to the MA, which is some sort of woven material. It’s less prone to scratching, doesn’t seem to leave any inner sleeve ’lint’ and, unlike putting it an HDPE sleeve, allows some air flow.