Record Cleaning Using Vacuum Machine for Cleaning and Ultrasonic for Final Rinse

@oberoniaomnia, 

how do you get from mass of pure dehydrated Tergitol to film thickness of 31 nm? Tergitol is something like a C33 hydrocarbon chain and generally hydrocarbon chains are around 1 nm thick (e.g., sugar). I failed to find any information on volume of dry Tergitol.

First is does not dehydrate, as a 100% concentrate - it's an oil with very low vapor pressure and a specific gravity of 1.006 g/ml TERGITOL™ 15-S-9 Surfactant which is essentially the same as water. 

There are a number of ways to calculate the record surface area.  A close estimate is the surface are of the flat portion, the groove area and the side-wall ridge groove area.  A simple groove length estimate is assuming an average groove velocity of the outer and inner grooves ((51-cm/s + 20-cm/s)/2) = 35.5-cm/s times a playback length of 20-min (1200-sec).   The average groove dimension of the 45-deg groove wall triangle hypotenuse is about 0.0016-inches so that each groove has about 0.0032-inches linear length that is about 0.0022-inch wide at the top and then add 10-15% for the side wall ridges,  Run all the numbers, and the surface area including grooves and side-wall ridges is approximately, close-enough, to 1-sq-ft, which make the film thickness analysis easier.  

The non-volatile residue (NVR) nominal film thickness (Contamination Control Engineering Design Guidelines for the Aerospace Community, NASA Contractor Report 4740, May 1996)  assumes the contaminant is uniformly applied and has a density of 1-g/cm³ = 62.43 lbs/ft³ (same as freshwater); and while a 1-micron film calculates to about 9.1 mg/ft², for ease of use 10 mg/ft² equals 1-micron thickness is used which is proportional.  Most water-soluble nonionic surfactants have a density very close to water, but much lower density contaminants will develop larger film thickness while denser contaminants such as hard water spots develop thinner thickness.  

I do a deep dive into the whole subject of “What is clean?” and for a record “When is a vinyl record clean?" in this free book -Precision Aqueous Cleaning of Vinyl Records-3rd Edition - The Vinyl Press Chapter XI which is pretty technical but given your background you should be able to wade through it.   

Enjoy,

Neil

@billstevenson 

I was going to post that the third edition is now on-line but you beat me to it!

By coincidence I spent the last few days cleaning my scant record collection though a cheap Chinese ultrasonic machine, 9 records at a time, having scoured Sydney to find Polysorbate 20 and Ilfoton.  By and large, the results have impressed me no end though obviously nothing can fix scratches. Clicks that have been audible on every play have magically gone away.

Only one record does not look spotless, and I think it was the one the police dusted for fingerprints after the turntable it was on was stolen around 1980!

I took several shortcuts which will probably horrify Neil.  For example, because Canberra's water supply comes from the Snowy Mountains, it is very clean, so I just used tap water passed through a Brita de-ionising filter instead of distilled water.  I just let the records air dry vertically in a rack after wetting in the Ilfoton bath.

@antinn I would like to thank you most sincerely for a truly impressive 'work of art and science' that obviously has been a labour of love for you.  In my opinion it is the most trustworthy document I have found through this forum.

The key is to buy your ultrasonic machine before the 5th. 

@richardbrand,

Thanks for the compliment, but not exactly a labor of love.  I started that project during COVID when I was retired (not anymore), and it kept me occupied and my skill sets sharpened.  And thanks to meeting up with Bill Hart @whart he stepped in with many good suggestions and as Publisher allowing the book be offered free through his site.  

Otherwise, I am not horrified by your use of Brita filter to deionize your good tap water.  First, the book makes not specific recommendation of distilled water.  The acronym DIW means demineralized/deionized/distilled water.  It just so happens that distilled water is plentiful and cheap in the US, while in the EU/UK demineralized/deionized is plentiful and cheap.  Neither provides any benefit over the other for record cleaning.  Second, the book offers a similar suggestion in Chapter VII.4.2 There are a number of vendors manufacturing countertop pitcher/filter systems that can produce Purified water. The ZeroWater™ units Water Filters & Water Filter Pitchers - Clean Water at Home | Culligan ZeroWater have the benefit of containing the most amount of demineralizer resin. Amazon.au sells ZeroWater Official Replacement Filter - 5-Stage Filter Replacement 0 TDS for Improved Tap Water Taste - System NSF Certified to Reduce Lead, Chromium, and PFOA/PFOS, 3-Pack : Amazon.com.au: Sports, Fitness & Outdoors but not cheap.  

Otherwise, assuming you bought a 6L UT tank reducing the number of records to no more than three and space them out about 25-cm and slowing the rotation speed to about 1.5-2-rpm should provide you with a cleaner record.  Most of the Chinese unit spinners are 24VDC and you can easily purchase a variable power supply to slow the rotation such as SHNITPWR 3V ~ 24V 3A 72W Power Supply Adjustable DC 3V 5V 6V 9V 12V 15V 16V 18V 19V 20V 24V Variable Universal AC/DC Adapter 100V-240V AC to DC Converter with 14 Tips 5.5x2.5mm 4.0x1.7mm 3.5x1.35mm : Amazon.com.au: Electronic.

Take care,

Neil

Richard, You wrote, "I just let the records air dry vertically in a rack after wetting in the Ilfoton bath."  Many of us have found that a rinse in pure water (as defined by you, Antinn, etc) after exposure to a detergent like Ilfoton, is beneficial.  You don't want to let the LPs dry with detergent on their surfaces, or at least they will sound better if you don't. I've done the experiment, with vs without a pure water rinse (in my case deionized, distilled water from my lab at NIH, where the building supplied distilled water that ran into a huge deionizer at the main sink) made a big enough difference that I have never not done it since. Of couse, my RCM is a VPI HW17, not a US machine.