Ultrasonic record cleaners

@antinn

The ultrasonic cleaner that I currently have it 6" in width, which leaves 3" on each side of the LP if I clean 1 LP at a time. Is there any practical or theoretical disadvantage if I were to clean 2 LP’s at a time, with a distance of 2" between each LP and 2" from each edge of the tub for a standard 180 W, 3 head, 40 kHz machine?
Thanks.

@drbond 

The spacing is fine.  BUT you have a 6L tank.  From a previous post you stated:  "4. I slowed the rotation of the motor to about 3 cycles per minute (this is using a low voltage adjustable DC adapter set at its lowest 3V), which is as slow as my adapter will turn the motor.".

Spinning at 3-rpm and a 6L tank, the most records you should clean is 1-record.  If you add another record, then to maintain maximum cavitation intensity you would need to decrease the spin speed to 1.5 rpm.  See the book XIV.5.3.e.

@antinn 

Thanks.  So it seems that, based on a flow calculation, due to speed of rotation, only 1 LP is recommended at a time in the 6 L tank.  And on review, it looks like 1 LP should be cleaned at a time based on surface area as well.  Your book also references a Kuzma rotater:  I went to their website, and they have similar recommendations as your book, but not nearly as detailed.  Unfortunately, it looks like the Kuzma website is also recommending Photo Flo 200, which has the Triton X, which is so bad for the environment, so perhaps you could send them an email to recommend the Tergitol instead? 

@drbond 

Kodak Photo Flow 200 is the wrong fluid to be used in a heated UT - read the book VIII.7; KODAK™ PHOTO-FLO 200: excerpt: " If the surfactant is Dow™ Triton™ X-114, the surface tension will be about 31 dynes/cm, the CMC will be 120 ppm, but the low 25°C/77°F cloud-point limits this product mostly to applications equivalent to room temperature."

Otherwise, Triton X100 is now banded from sale in EU/UK, and EU/UK cannot easily purchase Tergitol 15-S-9, but the book has some alternates see Chapter II.  But I am not sending Kuzma an e-mail (I am very protective of my e-mail).  The book is available for free, and people can use what they wish.  

WRT to surface area - the book XIV.3.3 (NASA) The sum of the parts cross-sectional area should not exceed 75% of the tank cross-sectional area. The tank cross-sectional area is associated with the surface where the transducers are mounted. For bottom mounted transducers, the cross-sectional area is the tank length x width, and the record shows only its width x thickness (12” x ~0.1”). For side mounted transducers, the cross-sectional area is the tank height x length and the record shows its width x height (about 0.67 ft²/record) for a much larger cross-section. This suggests why stacks of multiple records “can” be cleaned with a UCM with bottom mounted transducers, but with some loss of efficiency.

Bottom line:  for 40kHz keep record spacing about 1" but do not spin too many too fast.

@antinn 

The cloud point is an interesting property of Triton X:  I studied college level chemistry, and generally speaking, I thought most substances/chemicals were more solvent as the temperature of the solution increases.  But with Triton X, having a cloud point of 25C indicates that Triton X becomes more insoluble as the temperature increases above 25C. . .