Ultrasonic record cleaning (Pt 2)

This is our finalised DIY cleaner ‘kitset’ design.

It is a 3-piece ‘kitset’ designed for easy self-assembly, with only 4 screws.

An additional 3 screws attach a slow-rotating BBQ ‘rotisserie’ motor and the whole assembly fits neatly onto the top of a 6 Litre Ultrasonic Cleaner tank.

This is the finished Cleaner Kit installed onto the tank:

The DIY ‘kit’ consists of:

• 1.2mm stainless steel, precision laser-cut frame, 3 pieces.
• Stainless screws (4) & spring washers. (You just need a 2.5mm hex wrench (allen key) to assemble.)
• Stainless steel shaft with motor-drive coupler.
• Semi-soft record spacers (4).
• Clamp knobs (2).
• End bearing.

In order to be economical, we are beginning to make small batches of this kit, using machine-work where possible, minimising labour.  (If interested, the cost at this time is US$110 + postage, from New Zealand, less than 1kg packed weight.)  (Price at Apr 2019)

(Note: The laser-burn marks visible on the steel plates are only on the protective plastic film.)

You will need to purchase:

• Ultrasonic Cleaner tank, model no. PS-30A  (as pictured below, specify correct voltage for your country).
• BBQ rotisserie motor – there appears to be many variations of this China-made 2-rpm motor,  However the critical dimensions are the positions of the fixing-holes & the motor-drive.

The type of rotisserie motor used in our device.

Note: To fit the 12″ records, the tank top length must not be less than 325mm & to accommodate the DIY kit, the tank top width must be not more than 176mm (6.9″).

The tank top dimensions of my tank (Model PS-30A) are 325mm L x 176mm W (12.8″ x 6.9″).

This fitting is designed to hold (up to) 3 records at one time.  However, 4 records can be cleaned, by adjusting the spacers & clamp knobs to ‘centre’ the records.  Of course, you can also substitute thinner spacers and more records, but I prefer to have plenty of water space between records.

( 4 records loaded – 3 records only is recommended. )

Note how the detergent / surfactant creates a uniform fluid film over the entire record surface.

Here is a video of the cleaner (prototype) in operation:

Cleaning Fluid:  I am currently using the following mixture:

• Filtered drinking quality water (you can use more pure distilled water if you wish, but I think it’s unnecessary ).
• Triton X-100 pure detergent/surfactant, 0.1% to 0.5% dilution in the water.  (Pre-mix a 1% stock solution.)  I hear that Tergitol is an equivalent product – (non-ionic, neutral pH) detergent with no additives.
• [Update Dec 2019] If you wish to use a more environmentally-friendly detergent alternative to the Triton X-100 – I have been recommended Polysorbate 20 (eg. Tween 20) – https://www.rangeproducts.com.au/shop/raw-materials/polysorbate-20/ (Australia).

Unless your records are very dirty, avoid using alcohol – we understand that such solvents tend to remove plasticisers from the vinyl. (Ref. US Library of Congress.)

If the records are extremely dirty, you could add some enzymatic cleaner.

Heating:  At this stage, I am using no heating.  A little heating will assist cleaning I believe, but I have not experimented yet.  The ultrasonic ‘cavitation’ action actually heats the water a little, around +5deg C every cycle or two.

Cleaning time:  I suggest starting with at least 15 minutes.  Note that, as the records are rotating (2 rpm with this motor), the immersion time of inner grooves is less than outer grooves and both will be immersed for only a fraction of the cleaning time duration – approximately 1 minute and 3 minutes respectively, for inner and outer grooves.  (See Long-Section diagram above.)  So, 20 minutes (or even more) may be a good idea.

Drying :  After cleaning, the records will naturally air- dry quite quickly because the surfactant forms a thin surface film.  However it is probably a good idea to water-rinse them before drying.

Or, if you have a conventional vacuum record cleaner, it would be beneficial to vacuum-dry the record. (Using a clean vacuum brush or nozzle of course.)

Enjoy!

Pricing: (June 2020, at current exch rates) US$105 + postage, Euro 93 + postage, AU$149 + postage.

See also Ultrasonic record cleaning Pt 1.

Update 2020: An image showing how the spindle shaft is simply removed and re-inserted into the motor drive, when loading and unloading the records and spacers. (The spacers are semi-soft and do not damage the record labels.)