Thumbs up for ultrasonic record cleaning

@slaw - a few years ago, I was doing some research for a piece on DIY US (after having owned both the Audio Desk and KL). One of my sources of information was a long time manufacturer of factory line sized ultra sonic cleaning systems. (He didn't focus on vinyl, but was willing to spend an hour and a half over the phone and provide me with a lengthy email). He was emphatic about the value of a surfactant as part of the US process- it improved cavitation effect immensely. He showed me metal parts cleaned with and without surfactant (granted, not vinyl LPs, but still). When I jumped on the KL after the Audio Desk, I thought- simple- no chemicals to rinse off, no kludgey spinning applicator brushes, etc. But, the KL doesn't allow for the  use of surfactants (I haven't confirmed that directly with KL but suspect I am right). The DIY US, from my perspective, actually brings more to the table than either commercial, made for vinyl, US cleaner. You can add surfactant, and avoid some of the complications of the Audio Desk design; you can control heat, degas, and build a recirculation system with a filter (something KL now offers, but still no surfactant). And, your price of entry can be cheaper. When my KL finally dies, that's the way I'm going. (I still pre-clean on the Monks, and for certain records, do a reagent water rinse after the KL). For now, I'm changing out the water at 30 records or less, even though with pre-cleaning there is very little residue in the KL tank. (If I put a new record straight into the KL without precleaning, there will often be some grit in the tank when I drain it). 

@slaw @terry9
I think one of the values of terry’s input is the number of records you can effectively clean in one batch. There is a temptation to stack a bunch of records on a skewer and clean a lot at the same time. As someone upthread pointed out, bbftx started that monster thread on diyaudio that led to a lot of experimentation and was the starting point for Rush Paul’s seminal piece. bbftx did a similar computation, and noted that the upright 12" LPs act like baffles that block the bubbles, so you need some calculation for size of bath, power and frequency of transducers and spacing and number of LPs to optimize cleaning.
The science is a necessary part of it-- I’m not a scientist, but I can grok it with some research and help. I guess my point is not to dismiss the science as offputting- most of the hard core DIY’ers are pretty proficient people, but I think the DIY ultrasonic trend has reached beyond that hard core group to "regular" audiophiles. Thus, the anecodotal, the practical, and the scientific all have their place in the process.
Here’s to clean, quiet LPs!

I cannot answer all of your questions, in part because I am not mixing any solution for my ultrasonic for the reason stated above (I use a KL machine right now).
One issue I see as a potential hazard is the flash point of isopropyl even diluted, given the vapor. I believe that the chemistry suggests it should be below 3% of overall volume for the temperature you are achieving (Note, i am not a chemist so this should be checked). Is 3 ounces of alcohol in 6 liters really a 50/1 ratio? My maths suggested it was about 5% but there is a reason I didn’t major in math- somebody check me here.

Alcohol will work as a solvent, I’m not sure how effective it is as as surfactant (to break surface tension of the water, which is the goal). I believe one of its long time values in record cleaning generally is that it evaporates quickly. For effective formulae, you should read Rushton Paul’s article if you haven’t; there are others, including a formula Tima (Tim Ackerman adopted) that is posted on my blog; others, including @terry9 (who does have a scientific background) can offer more on the chemistry they have found effective and also weigh in on whether I’m being a nervous nelly about the amount of alcohol being used.
In general record cleaning- whether ultrasonic or conventional- the main points are effectiveness of the solution/method and the ability to remove the solution from the record, once done. I do know old school record cleaning folks that used Photoflo and no rinse. My impression is that it leaves a residue as do most of these chemicals and cleaners. That’s why I employ a rinse step. (Even though I’m not using chemistry in my ultrasonic, if I have a record that I’m especially concerned with, I will, once removed from the ultrasonic bath, do a rinse step using reagent grade water and point nozzle vacuum system (Monks or Loricraft- which doesn’t have the same issues as wand or velvet ’lips’ type RCMs)).

You said you just want "good enough" and don’t want to go all white lab coat-- there are some who say vacuuming after ultrasonic defeats the whole purpose of US cleaning given the potential for contamination and static caused by some conventional RCMs. You have to make a choice here- by experimenting with the chemistry- Tima does not do a rinse step using his brew (which I think is an adaptation of the London Jazz Collector mixture meant for conventional cleaning); others, like @@terry9, @slaw might be able to tell you what their experience is. But I think first stop is Rush Paul’s article if you haven’t read it.
Number of records per load- this has also been calculated- is in the original diyaudio thread and has been verified independently by other’s empirical experience-- I can give you links to some of this if you can’t find it but for a smallish bath it’s more like 2 records at a time with space in between.
There is good proof that a filter goes a long way- again, not to rely on what I publish but Tima did a follow up on his results using a filter-- pretty much the same one outlined in the diyaudio one that Rush adapted- and there was a lot of crap picked up by the filter. See [url]http://thevinylpress.com/record-cleaning-timas-diy-ultrasonic-rcm-followup-1/[/url] How long can you go before changing the water without a filter? I don’t know. Part of it depends on how much crap there is on the records to begin with I guess. (I pre-clean, so less of an issue).

@Alf- That link you provided is almost a horror show of what not to do in my estimation. Using dish soap- sure it will work, getting it off is another matter- I suppose hot water will work but it isn't necessary to use some detergent with a lot of other chemicals perfumes, etc to clean an LP--
getting the labels wet- yeah, that's not good-
using tap water as a rinse- full of minerals.
My experience buying a lot of used records is that ultrasonic isn't a complete answer but complementary to more basic cleaning. Some I know pre-clean without a record cleaning machine and then pop in the ultrasonic. 
I like the AIVS No. 15 cleaner for deeper cleaning- using it with a pad type applicator, like the Disc Doctor or MoFi makes for a very effective cleaning step. You must rinse this stuff off- I would use distilled water, perhaps a couple steps if doing it manually - with clean cloths. Then into a home brew ultrasonic. 
Some users may go straight into the ultrasonic for kludged up records- but my experience was the best results came from a combination of methods, which you could do on a budget. 
I'm pretty agnostic when it comes to brands- whatever works most effectively, with minimal harm caused to the records. 

@psag- I have a Monks too (an Omni). If I had to choose one machine, that would be it. But the synergy of cleaning on the Monks and ultrasonic- in both directions-- brings more to the table. Try it. 

@audiom3- don’t give up on a record just yet. One thing I learned, aside from the various fiddling you may do with the ultrasonic, is that a good old fashioned cleaning, using something like AIVS No. 15 and rinse will, in combination with US, sometimes take a record from noisy to clean. And it requires multiple cleanings sometimes too. It may not be worth the trouble for some easy to get, fairly cheap record, but if it is rare and valuable, well worth the trouble. I don’t rely exclusively on ultrasonic, but combine traditional cleaning with US and that’s where I’ve found the best results on troublesome records. (No guarantee- record could be permanently damaged, but sometimes, it works and worth the effort in the instances I mentioned).

You may find this explanation of different purification processes helpful:  [url]http://www.emdmillipore.com/US/en/water-purification/learning-centers/tutorial/purification-techniqu...[/url] The source is a manufacturer of equipment used in labs and hospitals.
In my interview with the LOC, the preservation specialist suggested the D/I was sufficient for records, the main objective being to remove mineral content. 
I've been told you can buy reagent grade II at places like Cosco. 
The reagent grade 1 cannot be shipped to a residence. It's also more costly. I now only use it to mix fluids and for rinse steps on the Monks. I used standard supermarket distilled in the US machine. 

@gbanderhoos-you raise some interesting points, starting with the actual operating frequency of your KL. I wonder how much variability there is among units in the field?
We are told that 40Khz doesn’t cause damage, at least for relatively short duration at fairly high rotational speeds (AD, KL); most of the DIY set ups seem to rotate at a lower speed, and for longer cleaning times, no? (I have only owned the AD and KL, but am aiming for a DIY when the KL goes, mainly for operational flexibility rather than low cost). I prefer point nozzle vac drying to forced air or passive air drying since I think it does a better job of removing the vestiges of contamination and fluid. I learned pretty quickly that the commercial US machines intended for LP did not clean challenged records that could get clean using AIVS No. 15, some vigorous agitation, pure water rinse, sometimes repeating the process, and then employing the US, with a final rinse and vacuum using high purity water.
I pre-clean any used record (and a few new ones that are obvious dirty) before going into the ultrasonic, using a Monks, and high purity rinse. I only find a deposit of very fine grit in the KL tank from new records that have not been pre-cleaned.
As for damage, I suppose you could test using a blank LP, examine for pitting, etc.-a point raised by a vendor of new cleaning service who opted for 80khz transducers run at low power (Perfect Vinyl Forever, who has recently been posting about his equipment and methods on various fora).
I’ve certainly heard no evidence of damage, which would be one good way to discern--most revealing to me are the results I get from a record cleaned both by conventional (fluid/vacuum/rinse/vacuum) and US, sometimes repeated conventional cleanings using AIVS No. 15 and reagent grade 1 rinse--where the record initially exhibits low level noise, raspiness, tracing distortion-often associated with groove damaged records. These can in many cases, not all, clean up to be quiet players. Once I clean a record using combined methods and it plays well, I don’t re-clean or do follow up re-cleans.
I’ve also had records that I cleaned decades ago using a VPI and who knows what fluid at the time (I tried several including some home brews) that play beautifully today.
I’ve also been reliably informed that using a surfactant in the US enhances the cavitation effect dramatically. Perhaps using a surfactant reduces the need for lower frequency, higher power and reduces the potential risk of damage, I don’t know. I found the earlier AD to be kludgey in operation, the KL of course doesn’t permit the use of additives as far as I know, thus my aim for a DIY which permits use of a surfactant.

@bydlo - i have not added any surfactant/detergent to the water since I’ve been using the KL. When I got it, I was using Reagent Grade 1, which seemed to be a waste of money. Now I just use distilled in the US, but for a finish rinse on valuable or challenged records, I’ll use the Reagent Grade 1 and vacuum on the Monks. As mentioned, when the KL goes, my plan is to try a DIY approach, largely b/c of the feature set, which includes the ability to use a surfactant to enhance cavitation effect.
For now, I just change out the bath water every thirty records, even though most of them have been precleaned. (Yeah, I’m a little compulsive, but I don’t have a filtering system hooked up to the KL).
Not to open a can of worms- I think this was discussed earlier in this thread- but the idea of alcohol and ultrasonic makes me a little nervous. I gather most of you are using only a small amount. Since I haven’t mixed any chemistry for ultrasonic, I can’t contribute to a meaningful discussion about what alcohol adds. I know in the old days, using vacuum, alcohol was commonly part of the cleaning fluid. I don’t think it is a terribly good solvent. Perhaps it is the evaporative properties. (I’m not concerned about damage to the vinyl since I think the exposure to the plastic is limited, but the flash point does concern me). Maybe I’m a nervous nelly.
There have been some good suggestions here on different chemistry. I use an lab grade detergent to clean my lab dishware which can be used in an ultrasonic machine. It isn’t very expensive. 1 part per 100 or 200 is recommended. It foams like crazy when I am hand washing the various glass I use hold brushes, and mix one of my RCM fluids (Hannl concentrate, which I dilute with the reagent water).  
I think there's a little Walter White in all of us. :)

@bydlo- for what it’s worth, the Monks brushes work really well on the Monks which runs at a higher rpm than something like the VPI. I don’t know what fluid you are going to use for pre-wash, but I’ve found that the velvet pad type, e.g. Disc Doctor/MoFi, do a better job with the AIVS No. 15 (which is what I use for heavy duty pre-cleaning). It allows you to delicately ’scrub’ the record. You have to pre-wet the applicator pad, which soaks up more than a brush. The applicators from Lloyd Walker are unidirectional pile and the easiest for me to handle. I will pre-pre-clean to get the grit or surface particles off using a mild fluid and brush (.e.g, Hannl, but you could use something else), and vacuum. Then use the AIVS No 15, let it soak, agitate (light scrub) and sit, doing this while the motor on the Monks is "off. The pads create more resistance/friction than the brushes and I don’t want to screw up the motor; there is also no need to spin the disc at speed to do the scrub/agitate phases. I don’t have to worry about grinding particulates into the surface b/c of the pre-pre clean. I will add more fluid, and agitate more. Then vacuum, rinse with high grade water, then US. If I’m really compulsive, I’ll do a vac dry on the Monks rather than using the blow drier on the KL which has helped get some remaining tracing distortion out of a few records.
Obviously, I don’t go to these lengths on every record. But, some need the extra work to get to a high state of play without any groove noise. And it works!

@bydlo- are you in the States? Try the AIVS No. 15 for the deep cleaning if you can. You must rinse afterwards though. 

@Labpro–– Although much of this thread is devoted to DIY methods, many of us have had the Audio Desk. I owned one before the "Pro" was introduced, and based on the recommendation of some early adopters, reduced the amount of "fluid" I put into the bath- not so much for cost-savings but to reduce the potential for fluid residue. Honestly, I could not hear artifacts from the cleaning on the original AD, at least when using just a capful, rather than a whole bottle of the fluid. (Robert Stein, the importer, may disagree, but he’s not a disagreeable person).
I have shared some records with a collector friend who has the "Pro" version, he loves it, and the records sound fine when played on my system, many states away from him. In a couple instances, I have done more intensive cleanings for him, but no rigorous comparisons of before and after. My take is that you should be satisfied with the performance of the AD, and there is some benefit to the ’no work’ approach.
There were some (ahem) issues with the early AD machines and most of us moved on. I bought the KL before AD introduced the "Pro" model, but the KL doesn’t allow for a surfactant. So, it’s trade-offs. Much of the attention on DIY is cost savings over the commercial US record cleaners, but some is getting better results than what those provide through a medical/lab grade US system, the use of surfactant, control of temp, frequency, de-gassing, filtration and other features or variables that you cannot control on the ready made for LP cleaning units.
My main issue with the AD when I owned it wasn’t the residue of the fluid, but that it didn’t do as good a job on problem records- I buy a lot of used, rare vinyl, some of it in less than pristine condition (not beat up copies, but ones that benefit from more intensive cleaning, combining manual cleaning, point nozzle vacuum and ultrasonic). Others may have a different view, but assuming you are dealing with new records or older records that were well maintained by audiophile types, you should not have any issues over cleaning quality.

@totem395 - Tomtem- i think you misstated the article which (correctly as I understand it) says that higher frequency = smaller bubbles. The theory, so far as record cleaning goes, is those smaller bubbles may do more to get into the grooves. But they are less powerful than the larger bubbles generated by lower frequencies when they implode.
I think the folks on the DIY Audio site have experimented to some degree with cleaning effectiveness of different frequencies. I like the idea of having a machine that provides alternate frequencies. It is a good article in talking about frequency and power. Thanks!