I'm going to start simple. Can always do more if it seems the records could be cleaner. Some folks express concern about over-cleaning and damaging them. Some recommend running the machine for half an hour. Others for 5 minutes max. With all sorts of additives. But then a few say one doesn't even need distilled water. The water here is extremely soft and clean (one of the four cleanest water systems in the country) so I may experiment with tap water.
Starting simple is a good choice. I found that a simple process works extremely well for cleaning records. For my record collection I only used distilled water and a non-ionic primary alcohol ethoxylate surfactant. Typically my cleaning time was 6 min, followed by a 1-2 min spin rinse and finally spin drying in a vertical position. For this entire process my records remained on my spindle assembly. When I first started cleaning my record collection, I typically cleaned 10 records at a time with a 1/2 inch spacing. I used this ultrasonic bath for over 30 years with excellent results.
Here are some key points that we observed in my laboratory using several analytical techniques to analyze sacrificial records before and after varying various cleaning parameters.
Only distilled water should be used. RO water is ok but typically not as pure as properly distilled water. I would not recommend tap water. Even soft tap water (10 to 20 mg/l) in an ultrasonic bath will introduce mineral deposits on a record surface. These mineral deposits can actually bond to the record surface or even be imbedded into the surface making them hard to remove.
Pure distilled water by itself works quite well in an ultrasonic bath but may not remove all contaminants.
Adding a little non-ionic surfactant improves the cleaning efficiency by lowering the surface tension.
Increasing the non-ionic surfactant concentration to the Critical Micelle Concentration improves the cleaning efficiency for more difficult to remove contaminants and contaminants present in higher concentrations.
Adding some Isopropyl alcohol also lowers the surface tension and helps to dissolve some contaminants. However I found that a proper non-ionic surfactant provides better cleaning efficiency.
Rinsing with distilled water is essential if using a surfactant or any other chemical component in the ultrasonic bath.
Regarding optimum cleaning time - We coated numerous sacrificial record samples with known contaminants to see how effective the ultrasonic bath was at removing them. For all contaminants, complete removal was observed within 1 to 2 min in a static (non rotating) ultrasonic bath using just distilled water and a non-ionic surfactant. This translates to ~ 3 to 6 min in a rotating assembly because ~ 1/3 of the record is in the bath at any given time. These experiments are the reason I settled on 6 min for my ultrasonic cleaning time. Longer times provided no cleaning advantage and can lead to some detrimental effects.
Only non-ionic surfactants should be used. Dish soaps typically contain a variety of surfactants including anionic surfactants as well as other non-essential ingredients. These surfactants and other ingredients can bond to the record surface and can be difficult to remove.
Recommended non-ionic surfactants include:
The
Dow Tergitol 15-S series of non-ionic secondary alcohol ethyxolate surfactants, especially
Tergitol 15-S-7.
TergiKleen, which is a blend of two Dow non-ionic surfactants – Dow Tergitol 15-S-3 and Dow Tergitol 15-S-9.
Ilford Ilfotol photographic wetting agent which only contains 2 ingredients, a preservative and a non-ionic branched alcohol ethoxylate surfactant.
Triton X-100 - which was developed by Dow many years ago, is an example of a non-ionic Octylphenol Ethoxylate surfactant. It works well for cleaning records but is not as environmentally friendly as the above listed surfactants.