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

@lewm 

my RCM is a VPI HW17, not a US machine

You might have picked up that I have a problem with TLAs!

In this context, does US mean useless or United States?  I thought the VPI was built in New Jersey?

By the way, I now enjoy my meagre collection of records as much as playing CDs.  The physical effort does make vinyl more involving!

Now when I am buying music in physical formats, I buy the SACD version if there is one, then vinyl if there is one, then CD if that is the only option.

Now to try to reduce the residual noise in my venerable Garrard 301.  It is not really audible at my normal listening position, but close up it is there!  Hard to know what comes from the vinyl ...

@richardbrand,

If you are spinning 9-records in a 6L tank, there are 2-problems - too much mass in the tank and you are overloading the tank, and even at a slow spin speed you are developing enough fluid flow/motion to pretty much kill most cavitation energy.  As the book addresses, if the flow in the tank is >50% of the tank volume/min, the ultrasonic cavitation energy drops quickly.  Try 3-record space ~25-cm apart and spin for 20-min.  I suspect you will get good results, and the time to clean 9-records would be the same at 1-hr.

As far as dilution ratios, it's in Chapter XIV, but it's a bit spread-out, but here they are for Polysorbate 20 and your 6L tank

• No rinse, wetting only:  0.0035 to 0.0050% (0.2 to 0.3-ml).  Adding 2.5% IPA has some limited benefit in getting a little better wetting, but add the IPA after adding Polysorbate 20 or the Polysorbate will not dissolve quickly
• No rinse, with some detergency 0.008% (0.5-ml).  Adding 2.5% IPA can help with the getting a bit better detergency but add the IPA after adding the Polysorbate 20 or the Polysorbate will not dissolve very quickly.
• Rinse recommended, full detergency:  0.0150% (0.9-ml).  Adding 2.5% IPA to this has limited benefit.

If you can buy the Nalgene Dropper Bottle at a low price - Nalgene Drop Bottle (2-Ounce) : Nalgene: Amazon.com.au: Sports, Fitness & Outdoors, it delivers 0.04-ml/drop.  Otherwise, assume an eye drop will deliver 0.05-ml/drop.

Good Luck,

Neil

@billstevenson Adding a small amount of lab grade ethyl alcohol to your final rinse will improve the groove wetting by lowering the surface tension and will improve the effectiveness of your final rinse, audibly so to my ears.

@orthomead,

Below is Figure 39 from the book that shows the change in surface tension of Ethanol and IPA.  There is not much difference between the two.  To get an appreciable surface tension decrease about 5% is required.  The record surface tension should be about 36-37 dynes/cm.  Getting the water surface tension close is enough to 'wet' the record.  

 Figure 39 – Water + Alcohol Surface Tensions of at 25°C from PACVR
(adapted with permission copyright 1995, American Chemical Society)

 Data for Figure 39 is from “Surface Tension of Alcohol + Water from 20 to 50°C”, Gonzalo Vazquez, Estrella Alvarez, Jose M. Navaza, Journal of Chemical and Engineering Data. 1 May 1995.    

Leaving the record slightly damp from the Teritol cleaning in the VPI seems to provide the reduction in surface tension in the rinse step in the HumminGuru.  Alternatively, the surfactant that is supplied by HumminGuru is also effective.  In my opinion, the addition of IPA to the US machine is not a good idea.  My thought process is a) it is not necessary and b) it could need to be in a higher concentration consistent with safety.