Ultrasonic cleaner size: 10L vs 6L - Page 1
Forum section: electronics / repair

author: SolderOcelot
author_rank: Contributor
timestamp: July 08, 2024, 03:42:09 pm
content: So I boughtthis cheap ultrasonic cleaner from AliExpressas my first ultrasonic cleaner ever to undo liquid damage on laptop motherboards. Yes, I cheaped out, but since these are being sold at big chains in US and UK I thought it might not be too bad as an entry model.I'm looking for advice from experienced users, specifically on the size. I'm very obsessive about getting the right size and I doubted long and hard and got the 10L instead of the 6L variant. Only the width is different and thus in the 10L variant you can lay the motherboard flat and in the 6L often times you have to lay it at an angle so it fits.Basket size 6L: 30cm x 12cm x 15cm (200W heating unit / 180W transducer)Basket size 10L: 30cm x 24cm x 15cm (200W heating unit / 240W transducer)Round 1So I took a laptop motherboard with some water corosion as a test sample. Here is the process of the first run:Fill it with Distilled water / IPA @ 6:1 ratioHeat the tank to 60°CLet it run for 5 minutes without board to degass because it has no dedicated "sweep mode" for degassingPlace the board in (damage facing down for optimal agitation) and let it run for 5 minutesResult: corosion only ~25% removedRound 2I talked to my neighbour and he said that I should have gotten the smaller tank because the agitation / vibration would then reach the board easier and you would need less runtime. So I did a second run with longer agitation time:I use the same liquid (lol)Heat the tank to 60°CLet it run for 15 minutesPlace the board in (damage facing down for optimal agitation) and let it run for 5 minutesResult: the gunk is gone and you can even see factory flux getting removed / displaced as well so effectiveness increased.However, you can see ultrasonic cleaner damage to the paper sticker, see photo. So a 15 minute runtime might be risky.I have 2 straightforward questions:1) Do you think the 6L basket size is enough for most laptop motherboards?2) Is it true that less runtime is needed for the smaller tank and thus is safer for laptop motherboards (or any other populated pcb for that matter?

author: SteveThackery
author_rank: Super Contributor
timestamp: July 08, 2024, 04:31:47 pm
content: I'm afraid I cannot contribute anything useful regarding the suitability for a motherboard. However, I have been using ultrasonic cleaners for 35 years or so.The ultrasonic power is important, and in particular in relation to the volume of the fluid. Some low cost cleaners use the same circuit board and transducers over two or even three different sized models. 50W of ultrasonic power in a small tank can punch holes in metal foils, but in a larger tank can be insufficient to do a decent clean.I've never heard of mixing water and alcohol for use in an ultrasonic cleaner, but I must emphasise again that I haven't used an ultrasonic on electronic boards. In the early days I used trichloroethane 1.1.1, which worked brilliantly, but of course every time you uncapped the bottle you wiped out another cubic mile of ozone (this is an exaggeration, but you know what I mean!). Nowadays most ultrasonic cleaning fluids seem to be aqueous: surfactants plus water, although those intended for use on metal parts usually have a hydrocarbon base.In terms of cleaning time, I often let the machine run for up to 30 minutes. There is a reason: if your cleaner does not have a heating element then the longer you run the cleaner the hotter the fluid gets, and that always (in my experience) helps the cleaning action. A heating element is definitely worth paying a bit extra for, in my view.I realise you know this, but I want to emphasise it: the transducers are affixed to the bottom of the tank by a special cement which is glass-hard, in order that it doesn't absorb any energy from the transducers. It is therefore very important NOT to pour hot water into the tank, because the sudden differential expansion CAN cause the cement to crack. Not always, but yes, it has happened to me.Nearly all cleaners use a swept frequency, but usually swept at the mains electricity frequency which I suspect is too fast. I modified one of my cleaners to sweep much more slowly, and I think it is better because it allows the vibration patterns to build up in the fluid. Some cleaners offer a manual control over the frequency (you should set it for maximum agitation), and others have a closed loop system where they automatically find the frequency at which maximum energy transfer from the transducers to the fluid takes place.

author: SteveThackery
author_rank: Super Contributor
timestamp: July 08, 2024, 04:39:30 pm
content: About your question 2 specifically: it isn't a straightforward answer because it depends on the power density in the fluid. If the same wattage is being concentrated in a smaller tank then yes, the necessary runtime is less. Otherwise you'll need to compare the watts-per-litre of each machine to compare.About degassing: perhaps my experience is insufficient, but I've not come across a "dedicated sweep mode" for degassing. All of mine pulse the power at about 0.5Hz and 50% duty cycle to do the degass. Maybe the more professional ones use special sweep modes?Edit: I'm too embarrassed to put up yet another post, so I'm going to cheat by adding some stuff to this one! Another point I want to add: some cleaners have a plastic lid, others a metal one. In general I've found that the plastic ones tend to be a better fit, and importantly, they mute the horrible noise from the cleaner more thoroughly. I cannot guarantee this is true for all cleaners, but perhaps you will arrive at your own conclusion. I can't stay in the room for one of my cleaners because the noise is unbearable - a really harsh, high frequency, teeth-tickling racket.Be aware, though, that if you do use one with a plastic lid then you probably won't be able to use anything other than water (and some alcohols, maybe?) in the tank. In my experience most solvents eventually end up causing the plastic to fog, craze and - if you wait long enough - crack. Some make the plastic sag instead.If you want to put lots of small, and possibly delicate, parts in the cleaner you ought to put them on a platform so they are off the base of the tank. Plastic trays absorb ultrasonic energy, so something stainless steel would be better. Fine meshes (like a tea strainer) greatly attenuate the ultrasonic vibrations.One last thing. The design of the cleaner in terms of keeping the cleaning fluid away from the electronics inside is obviously very important, but you'd be amazed by some of the crap designs. They all have a seal around the top of the tank, but the good ones also have a kind of double-walled arrangement whereby any fluid that does get past the seals is caught and directed to a drain hole underneath the cleaner.Sorry - this has become a bit of a brain dump.

author: SolderOcelot
author_rank: Contributor
timestamp: July 08, 2024, 05:05:54 pm
content: First of all, thank you for all your input. Although it doesn't directly address my individual issues, still an interesting read.Quote from: SteveThackery on July 08, 2024, 04:31:47 pmThe 6L variant has 200W heating power and 180W transducer power. The 10L has 200W heating power and 240W transducer power. Seems like they took this into consideration.Quote from: SteveThackery on July 08, 2024, 04:31:47 pmFinding the right recipe is the next project! Here in NL there aren't many ready made stuff to be found.Quote from: SteveThackery on July 08, 2024, 04:31:47 pmTrue, but mine does! :-) it takes 45 minutes to heat from 24C to 60C.QuoteMine is metal and I can not sit in the same room..

author: SteveThackery
author_rank: Super Contributor
timestamp: July 08, 2024, 05:23:14 pm
content: Quote from: SolderOcelot on July 08, 2024, 05:05:54 pmLooks like the 6L one should be a bit more punchy, then. By the way, I'm sure some boffin will tell you that "watts per litre" is not the whole story, but it seems about right to me.

author: metrologist
author_rank: Super Contributor
timestamp: July 08, 2024, 08:23:48 pm
content: I got the 10L version and am happy with it, although I think the heating power is 300W on mine. I believe the 6L tank has 3 transducers and the 10L has 4.Boffin: Yes, you have to take into account power losses from the surface area of the tank relative to the volume

author: SolderOcelot
author_rank: Contributor
timestamp: July 08, 2024, 08:29:39 pm
content: Quote from: metrologist on July 08, 2024, 08:23:48 pmSurface area meaning also the walls right? I'm asking this because my theory is that the waves are stronger in the bottom of the tank and weaker in the top part by diffusion. In that line of thinking a 10L with lower wattage per liter would clean better than a 6L because the PCB's can lay flat and have most of their surface closer to the floor of the tank.Or am I overanalysing it?

author: tszaboo
author_rank: Super Contributor
timestamp: July 08, 2024, 08:39:43 pm
content: Get the bigger one. The items in it are not supposed to touch the wall. You are loosing space here and there, and the first time something doesn't fit you regret it.I certainly did when only half my H0 model train tracks fit into it for cleaning, because the others were too big. Also you want to run it in another room or wear ear protection (or preferably both).

author: SolderOcelot
author_rank: Contributor
timestamp: July 08, 2024, 08:43:28 pm
content: Quote from: tszaboo on July 08, 2024, 08:39:43 pmThis comment is more or less the type of confirmations I was looking for. I already had made the decision and have the 10L sitting here. I was just slightly tempted to swap it for a 6L because I thought it would be more effective for my use purposes because of1) my neighbour's statements2) seeing Louis rossman using a 6L which barely fits his logicboardFor the record by the way: I always use a basket and never let anything touch the tank walls.

author: metrologist
author_rank: Super Contributor
timestamp: July 08, 2024, 11:22:46 pm
content: Quote from: SolderOcelot on July 08, 2024, 08:29:39 pmYes, somewhat overanalyzed because these tanks are really on the small scale, and yes the walls of the tank are where more losses occur. Wave propagation through the liquid is not much an issue, more so when reflecting off the sides. You can also do tinfoil tests to see any hotspots, but I could not really find any. I would have opted for a 15L if I had planned on regular use, but glad I did not get a smaller one.A tip is I've seen folks use jars to contain smaller pieces and more expensive cleaning solvents, so you don't have to fill a 10L tank with expensive cleaning agents, and then they're easier to reuse. It works great.

author: CaptainBucko
author_rank: Regular Contributor
timestamp: July 09, 2024, 02:20:48 am
content: Quote from: metrologist on July 08, 2024, 11:22:46 pmI don't use a jar myself, but I do use smaller zip locks bags so I can just use plain tap water as the main liquid in the tank, both with ISO and PCB Cleaner solution where required. It works really well.

author: SolderOcelot
author_rank: Contributor
timestamp: July 09, 2024, 10:38:09 am
content: Quote from: metrologist on July 08, 2024, 11:22:46 pmI thought plastic is too good at dampening the soundwaves..

author: CaptainBucko
author_rank: Regular Contributor
timestamp: July 09, 2024, 11:30:56 pm
content: I have not noticed any issues myself, but I don't doubt it is (slightly) less efficient in sound wave transmission.The benefit of using the barest minimum amount of cleaning product is significant however.

author: MathWizard
author_rank: Super Contributor
timestamp: July 10, 2024, 01:10:30 am
content: So what happens if you don't degas ? Do bubbles just stick to the PCB and not get cleaned as good ?I've watched video's of UC, but don't remember the noise, certainly not a loud one anyways.Do people dip big things like whole computer PSU's in them ?? I have no plans to get an UC. Just that much distilled water and whatever else must get expensive.

author: CaptainBucko
author_rank: Regular Contributor
timestamp: July 10, 2024, 04:04:04 am
content: Quote from: SteveThackery on July 08, 2024, 04:31:47 pm1,1,1Tricho was awesome stuff - I used to joke it was the main flavoring ingredient in Terry's Chocolate Orange due to its subtle sickly sweet citrus odor.

author: CaptainBucko
author_rank: Regular Contributor
timestamp: July 10, 2024, 04:19:40 am
content: Quote from: SolderOcelot on July 08, 2024, 03:42:09 pmTry using a proper PCB cleaner, not IPA + Water Mix. Depending on your country there will be various suppliers. I find the PCB cleaning solutions much more effective and removal of contamination, so you don't need to spend so much time with the item in the ultrasonic cleaner.

author: SteveThackery
author_rank: Super Contributor
timestamp: July 10, 2024, 08:29:44 am
content: Quote from: MathWizard on July 10, 2024, 01:10:30 amTruth be told, I haven't noticed any difference. Also, I've observed that no matter how long you degas, you still get bubbles forming and rising to the top. Or at least, that's what I've found with mine.Perhaps its importance depends on the particular fluid you are using.

author: SolderOcelot
author_rank: Contributor
timestamp: July 10, 2024, 10:08:19 am
content: Quote from: MathWizard on July 10, 2024, 01:10:30 amMore bubbles = more risk of damage. Look up "aluminum foil in ultrasonic cleaner test".Quote from: CaptainBucko on July 10, 2024, 04:19:40 amI wonder what it is about these solutions and why I wouldn't be able to make it myself. So far I've understood these are the essentials:Carrier (distilled water)Solvent (IPA or something else)Surfectant (dish soap)

author: SteveThackery
author_rank: Super Contributor
timestamp: July 10, 2024, 10:49:45 am
content: Quote from: SolderOcelot on July 10, 2024, 10:08:19 amI'm not sure that follows. There is a mechanical cleaning action with an ultrasonic cleaner, and any mechanical action can lead to damage. You manage this by keeping the cleaning time as short as possible commensurate with getting a successful clean. Also, and perhaps obviously, the higher the ultrasonic power density in the fluid, the greater the risk of damage.I don't see how either of these relate to the visible bubbles. In fact, the proposed relationship seems to be the other way round. That is, degassing to reduce the bubblesincreasesthe cleaning action. So it would seem that the bubbles themselves actually reduce the mechanical cleaning action (by absorbing the shockwaves because the bubbles are "springy") and thus the risk of damage.Only if the bubbles are used as an indicator of the power density could you say that more bubbles = more risk of damage. That's why I think the opposite to SolderOcelot: insufficient degassing reduces the cleaning action and the risk of damage.(PS:) You can't have a mechanical cleaning action with no risk of damage. The fun you can have perforating aluminium foil is simply a demonstration of that fact. You can also use it as a crude indicator for how powerful the shockwaves are. That is all. Degassing the fluidincreasesthe shockwave power, thus also the cleaning action and the risk of damage.

author: tooki
author_rank: Super Contributor
timestamp: July 10, 2024, 03:54:06 pm
content: Quote from: SolderOcelot on July 10, 2024, 10:08:19 amCommercial PCB cleaners/flux removers for ultrasonic areaqueous, i.e. not solvent-based. The key ingredient is a saponifier (lye or similar), plus surfactants (probably something closer to what’s in all-purpose spray cleaner like Cilit Bang), plus corrosion inhibitors and probably redeposition inhibitors. These cleaners don’t rely on solvents to dissolve the flux, they use the saponifier to make the flux water-soluble.(Solvent-based cleaners that can be used in ultrasonic do exist, but they don’t contain water. At least I’ve never seen one that does.)Edit: I’m not so sure now. One aqueous cleaner (Safewash Super, SWAS) does contain various alcohols, but they aren’t normal alcohols (isopropyl, ethanol, etc) and I don’t know enough about chemistry to understand whether the alcohols used are actually “solvents” in the usual sense or not.

author: SolderOcelot
author_rank: Contributor
timestamp: July 10, 2024, 04:33:01 pm
content: Quote from: tooki on July 10, 2024, 03:54:06 pmI'm not a chemist, but the fact that they rely so much on saponifiers is maybe the reason why so many people swear by just distilled water & dish soap?Also, as a Swiss I'm going to assume you use ultrasonic cleaners daily on Rolex parts

author: jpanhalt
author_rank: Super Contributor
timestamp: July 10, 2024, 05:10:24 pm
content: @tookiI wonder whether Kester has spies on EEVBlog.Kester's SDS for aqueous flux removers (e.g., #5768) used to say what was in it (2-butoxyethanol and ethylamine). The same ingredients are in acrylic floor stippers. Now Kester is more generic:https://www.macdermidalpha.com/sites/default/files/sds_pdfs/NA/4060034_KESTER%20SDS%20GHS%20AMERICAS_ENGLISH%20%28US%29.PDFLook for a household or commercial product with those two ingredients. They are extremely common, and the cellosolve is generally considered non-toxic. The recommended final concentration of butoxyethanol ("butyl cellosolve" and other names) is about 10%. The amine is the "saponifier." Add a little non-ionic surfactant, if that makes you feel better. I use Zep brand heavy duty acrylic floor stripper from my local big box store. I believe it is distributed in Europe, but not in Australia yet. It's about 30%, so I dilute 1 part to 3 parts total with water. You could probably use even less of the butoxyethanol. Then rinse well with water (I give two minutes in the ultrasonic with the final rinse and same time for initial cleaning.)

author: SteveThackery
author_rank: Super Contributor
timestamp: July 10, 2024, 05:34:54 pm
content: I use non-aqueous fluid for small steel components like watch parts, in order to avoid any risk of rusting.

author: tooki
author_rank: Super Contributor
timestamp: July 10, 2024, 09:10:55 pm
content: Quote from: SolderOcelot on July 10, 2024, 04:33:01 pmI don’t think I am getting your point — dish soap isn’t a saponifier. (Saponifiers turn something else into soap. Like using lye to turn vegetable fats into soap.) So you’re not using a soap to remove rosin, you’re turning the rosin into a soap.And who are these “many people” who rely on dish soap and water?Quote from: SolderOcelot on July 10, 2024, 04:33:01 pmWell, I live in Switzerland and have citizenship, but I’m not actually Swiss.I think the last time I wore a wristwatch was in the 90s. As soon as I had a cellphone (1998 IIRC) I stopped. And it was just a Swatch. :p I’ve seen Rolex watches in shop windows though!

author: SteveThackery
author_rank: Super Contributor
timestamp: July 11, 2024, 12:05:32 am
content: Quote from: tooki on July 10, 2024, 09:10:55 pmI think Rolex are seriously over-rated. People in the know buy Zenith.

author: coppercone2
author_rank: Super Contributor
timestamp: July 11, 2024, 02:50:26 am
content: I think bigger is better with more isotropic behavior without fringe focusing effect from edge reflection (rounded edges parabola like) that can lead to spot damage

author: tooki
author_rank: Super Contributor
timestamp: July 11, 2024, 06:34:03 pm
content: Quote from: SteveThackery on July 11, 2024, 12:05:32 amLike the old TVs?Just kidding. But I honestly know nothing about watches beyond a few brands I’ve heard of. (Omega, Tissot, Jaeger, and Rolex come to mind.) As impressive as I consider the micro-machining required to make them, I have no use for the product!

author: jpanhalt
author_rank: Super Contributor
timestamp: July 11, 2024, 07:09:36 pm
content: Quote from: SteveThackery on July 10, 2024, 05:34:54 pmJewelers in America used a cyanide containing aqueous cleaner for watches and other jewelry. An uncle was a jeweler from the early twenties for over 30 years. In the 1950's, he was till using the same type of solution. After agitation in the sodium/potassium cyanide solution (probably some other stuff was there too), the basket of parts was rinsed and dried in fine sawdust. He told me a story that when the stock market crashed, some heavily leveraged jewelers drank the solution to commit suicide. That was his way to warn me it was dangerous if not used properly. Apparently, that solution was still available and used in the 21st century:https://www.researchgate.net/publication/281743306_Acute_Cyanide_Poisoning_from_Jewelry_Cleaning_SolutionsThere are some steel parts in watches, such as stems and mainsprings, but using that wash did not cause rusting. The advantage of aqueous solutions is they are far better than any non-aqueous solution at removing inorganic salts, dirt, dust, etc., and rinse solutions are as cheap as water.EDIT: I am not recommending that solution of ultrasonic cleaning. The degassing effect could increase the danger a lot.

author: mendip_discovery
author_rank: Super Contributor
timestamp: July 11, 2024, 07:54:26 pm
content: I had the transducers on mine fall apart. I fitted new ones using arledite to glue them on. Works great now. I use it for cleaning motorcycle parts, mostly carburettor and stuff.Go big or go home. You will find it easier to use than a small one.I never worried about the bubbles as I thought that was part of the idea of these cleaners as the cavitation is what is doing the cleaning. Then again I don't put boards in mine.

author: coppercone2
author_rank: Super Contributor
timestamp: July 12, 2024, 03:17:29 am
content: I really think people need to look into electro cleaning. It takes some research but brush and dip electrocleaning are powerful techniques that don't require anything too dangerous (just wear goggles).I electro cleaned my HP RF impedance analyzer test fixture gold parts and they came out looking better, the solution got a little dirty and it took me only a minute with house hold chemicals and the lowest power and cheapest DC power supplyI am telling you these methods are powerful, it just requires some things that most people find way too hard (alligator clips and getting the polarity right).I think its because people think that its way more sensitive to the options that you have like partial AC, Pulse, frequency, etc. Really, the parts are not going to get easily messed upSame for the weld cleaning industry, they made up a paper tiger out of all the god damn options that you have. What current, if its AC or DC or what brush... jesus.. it might have a bit of use if you wanna get the settings right for the first time for grumpy ass welders that refuse to put down the grinder... but its like the most insensitive god damn thing there is. You tune it with a current knob while your working to get the correct results like finding a radio station... but if you read the literature they make you feel like your part is gonna fucking disintegrate if you get it wrong LOL. I think alot of people shy away from the process because they have some ridiculous idea about how it actually ends up working in practice. The reality is kind of like deciding how hard you need to rub a brillo pad. The impression from literature is that its working with a overloaded Romulan Disruptor.

author: SteveThackery
author_rank: Super Contributor
timestamp: July 13, 2024, 09:41:42 am
content: Quote from: mendip_discovery on July 11, 2024, 07:54:26 pmIt is the cavitation, but not of those visible bubbles. The bubbles that do the cleaning are microscopic.I've just checked my supplier: most watch cleaning solutions are waterless, but there are a few that come as a concentrate which you dilute with water. They claim to have an anti-rusting additive.

author: watchmaker
author_rank: Unknown
timestamp: July 13, 2024, 10:43:19 am
content: I agree with the electro cleaning, although I use ultrasonics. The reason watchmakers use ultrasonic is because of the requirements for getting a parts account. But every jeweler is familiar with elector cleaning.The disadvantage of ultrasonic is its very reason for use; cavitation. I have seen the plating of Omega mvts removed and the bimetallic balances of high grade vintage watches destroyed by either too much power (this was adjustable on older machines) or being left in too long. The brass on the balance becomes very friable and it's action is destroyed.As for Rolex vs Omega, this is a religious argument. And we all know how well that worked in Switz before the Federation.

author: SteveThackery
author_rank: Super Contributor
timestamp: July 13, 2024, 08:49:28 pm
content: Thanks for that information, Dewey.There is something I don't understand. How can electrocleaning remove contaminants such as grease and oil from a surface? These are waterproof and non-conductive, so I don't understand how current can flow to or from such surfaces.https://www.sharrettsplating.com/blog/what-is-electrocleaning/This webpage seems like a good overview of the subject, but it says that the bubbles are formed "under" the contaminants, but that doesn't make sense to me for the reason given.

author: SteveThackery
author_rank: Super Contributor
timestamp: July 13, 2024, 08:53:40 pm
content: Quote from: watchmaker on July 13, 2024, 10:43:19 amIt's also worth pointing out that ammoniated cleaners are popular for (especially) clock repairs, but prolonged immersion of brass in ammonia destroys its integrity. I've read that it dissolves the zinc from the brass, but I don't know if that bit is true or not.

author: coppercone2
author_rank: Super Contributor
timestamp: July 13, 2024, 09:48:53 pm
content: Quote from: SteveThackery on July 13, 2024, 08:49:28 pmwell its not quite that simple. You require a degreasing step, and the most common electrocleaners use a base, or mixture of bases. TSP, hydroxides, carbonates, which will dissolve grease.I don't think it will get something like a drop of tar off your cleaning work. I thinks its more along the lines of at the exposed area, super active 'stuff' is formed by electricity, and the bubble, that kind of undermines and pulls the grease adjacent to the clean spot off.And if you ever play with paint stripper you will notice what it does to grease or paint. It swells up and wrinkles and seems to absorb the chemicals. I would not be suprised if the thinner areas of grease turned into electrically conductive 'gels' after being exposed to the solution. This effect is present, but you need much less concentration of it for electrolytic cleaning to start doing work for you. If you wanna just scrub it off, you pretty much need severely caustic mixtures (i.e. 50% NaOH)It does not just uniformly dissolve, you start seeing like... crap being lifted from the surface and floating around (big "chunks" that can be filtered out of the solution later). To me, this implies that the electrocleaning is disturbing a base level bond near the surface of the metal with the contaminant. It very much reminds me of what happens to a frying pan thats caked and soaking in soap for a day after you first start to agitate it with a brush, but without the brush.The only thing I don't like is the smell of it. Its very faint but I just find it very disagreeable.

author: SteveThackery
author_rank: Super Contributor
timestamp: July 13, 2024, 11:41:54 pm
content: Quote from: mendip_discovery on July 11, 2024, 07:54:26 pmExcept in this case the bigger cleaner has a lower power-per-litre than the 6L one. I do agree that a larger tank is more useful though.

author: watchmaker
author_rank: Unknown
timestamp: July 14, 2024, 12:09:06 am
content: Quote from: SteveThackery on July 13, 2024, 08:53:40 pmSteve,Two things about ammonia in cleaning solutions. It is waste. Excess ammonia means the proportions for making the soap are wrong. How do I know? I hold the tradmark to "Historic TImekeepers Ultrasonic Cleaner" as sold by Timesavers and others for two decades. It was a low ammonia alternative to L&R which forced them to reformulate.Secondly, ammonia only degrades items like stamped brass. It was uncovered as a result of brass cartridge failures in the imperial UK army. The myth about it attacking brass clock parts was created by a guy back in the days of the Syracuse Clocks listserv (1994 to about 2002). This guy said he had thousands of photomicrographs of SCC failures but when we started calculating man hours and dollars, we pinned him down and he had to admit it was all a thought experiment a al "Sir"Cyril Burt (nature vs nurture twin studies).But when a lie is repeated often enough....Look up research on Stress Corrosion Cracking. Last I looked it all involved drawn or stamped brass in high pressure ammonia environments.It is really like "personal magnetism" used to explain why a watch performs poorly.Cavitation is the concern for timepieces. In fact,for ancient items, I will use ivory soap in very hot water lathered up on a very soft brass bristle brush (feels like a dust brush almost). With this, I can remove fingerprint stains on chronometer plates withoutharming the spotting (decoration). But if the prints are acid etched into the brass, that remains.Gold gilding comes up like new.

author: SteveThackery
author_rank: Super Contributor
timestamp: July 14, 2024, 09:24:30 am
content: Thanks, Dewey, that's all really interesting.One of my British Horological Institute tutors said the same thing about the types of brass affected by ammonia. I have actually damaged one clock part in this way - I accidentally left it immersed in ammoniated clock cleaner for three whole days. The result was to give it a fine frosted look rather than its original shine. I don't know if there were any structural effects - no way of knowing.As a rule I use aqueous ammoniated L&R on clocks; on watches I use petroleum ether followed by isopropanol - the two different solvents seem to clean up the old lube pretty well. Let me know if you think this is the wrong approach.

author: jpanhalt
author_rank: Super Contributor
timestamp: July 14, 2024, 10:17:51 am
content: Quote from: SteveThackery on July 14, 2024, 09:24:30 amI don't do clocks or watches anymore, but I still enjoy working with mechanical parts. To me, petroleum ether means short chain, non-aromatic hydrocarbons, like hexane. It is hard to get in the US. Mineral spirits/paint thinner is similar but much higher boiling. I use VM&P Naphtha, which is widely available, for fine cleaning in the house and Stoddard or similar for heavy grease in the barn shop (e.g., my parts washer).* I like them as the increased aromatic content helps with grease and sticky labels. I sometime wash with an alcohol, acetone, or MEK.I came across a reference that may help clear up all of the confusion about names for hydrocarbon solvents:https://cool.culturalheritage.org/waac/wn/wn29/wn29-2/wn29-204.pdfJohn*"Parts Washer" labeled solvents are expensive near me. That is, compared to the days when when you could go to a a local Mobile station and pump it like gasoline. Fortunately, there's a well known dragstrip nearby (Norwalk Speedway). It's supplier is quite cheap and is willing to sell to me in 5 to 10 gallon amounts. It is basically Stoddard.

author: coppercone2
author_rank: Super Contributor
timestamp: July 14, 2024, 04:30:39 pm
content: oh no not hexane petroleum ether is a very low boiling point solvent designed to boil at the same point as diethyl ether when colliqually refereed to in the USA by most places. It plumes. hexane is a good 30 degrees higher boiling point. I think mine was 30-35C boiling point from Sigma.Petroleum ether is not known to be nearly as toxic as hexane. Some people might call it zippo fluid, but its available in very high purity as a lab reagent. Hexane has a bad rep. Heptane has a better reputation. Petroleum ether has a much lower point then benzene, which is the most harmful organic solvent in common use, so its safer in that regard since if it won't have benzene in it because of a very big boiling point difference.The benefit over ether is that it does not absorb water, so it can be stored easier( PE is very non polar). ethyl ether is probobly biologically safer, but possibly more explosive and has strict storage requirements with moisture absorbers and also stabilizers to prevent peroxides from forming (which can explode), but its usually not a problem for cleaning, more like if you distill a bunch of ether out of something and are left with a big glob of ether peroxides in a flask for organic extractions.Keep in mind though, plumey solvents can accumulate vapors in low spots. You gotta be well ventilated to work with that in large quantities. You could end up with a plume of vapor on the floor that can ignite easily because of its low flash point... i.e. a switch clicking on in a fridge.Its hard to work with if you wanna wipe something down because it really evaporates fastThis is what I would expect in a USA labhttps://lab.honeywell.com/shop/petroleum-ether-77399

author: jpanhalt
author_rank: Super Contributor
timestamp: July 14, 2024, 05:18:41 pm
content: I don't know what your link is selling at that outrageous price. What we called petroleum ether light boils at 60° to 70°C. Hexane boils at the higher end of that range; however, it is a mixture. When I was in school, we did not have UV grade hexane. We started with technical grade 60-70 and purified it to get a UV cutoff of about 220 nm, which was sufficient for our needs. Its volatility is hardly like diethyl ether (or methylene chloride).

author: coppercone2
author_rank: Super Contributor
timestamp: July 14, 2024, 05:36:12 pm
content: I don;'t see the point of calling it ether, its usually used when you would wanna use ether for its volatile properties but without moisture restrictions without going to butaneI would call that naphta. The beauty of the PE is that it evaporates your sample really quick (i.e. dirt oil extraction for testing for pollutants), which is very useful for a analytical lab that is tasked with testing a sample. It is extremely non polar.If it has a high BP then its not very ether likeOften used if you find oil on dirt and it needs to be tested for environmental reasons.That one i linked is 30-40C, ethyl ether is 35c, its real close, the lab procedures behave largely the same for extractions with greater safety margin and no moisture controls!And since the boiling point is so low, you know your not adding anything that will be hard to extract from your extracted oil before it gets tested for say PCB or other additives. A higher BP thing might linger in the tiny amount of oil you extracted then be a pain to remove later without disturbing the mixture thermally. Butane would work here too but its hard to work with for normal lab people, but if you had a special contained machine it would be better probobly.

author: SteveThackery
author_rank: Super Contributor
timestamp: July 14, 2024, 10:11:28 pm
content: I bought my most recent petroleum ether from eBay, and the supplier offered it with a range of different boiling points.I found that the lower boiling point products were not obviously any more effective as a solvent for solidified old oil than the higher boiling point versions, so I now use one rated at 100 - 120 Celsius boiling point.The BP ranges are: 40 - 60, 60 - 80, 80 - 100 and 100 - 120 Celsius.

author: jpanhalt
author_rank: Super Contributor
timestamp: July 14, 2024, 10:34:48 pm
content: 100° to 120°C is the octanes range. I utilized isooctane (bp 99°) for a tricky crystallization of an unexpected aromatic hydrocarbon (identified as tetrabenzanthracene, C30H18) from benzene. That was in a former life. I like the sweet smell of isooctane. Your pet ether probably doesn't smell so good.Are we far enough OT yet?

author: coppercone2
author_rank: Super Contributor
timestamp: July 15, 2024, 02:31:28 am
content: the other benefits of the PE is that its a mixture of various things, usually solvent mixtures work better for unknown samples because you never know what has the best solubility, regardless of the BP range, you get a bundle of solvents

author: SolderOcelot
author_rank: Contributor
timestamp: July 15, 2024, 10:04:29 am
content: Well after progressing to a second page on this thread I still don't know if I should swap my 10L ultrasonic cleaner for the 6L but I have now acquired a bachelor degree in chemistry having read all these comments.

author: jpanhalt
author_rank: Super Contributor
timestamp: July 15, 2024, 10:24:30 am
content: Quote from: SolderOcelot on July 08, 2024, 03:42:09 pmMy reading of the first page was that almost everyone recommends the larger unit. For me, any advantage of the 6L would be offset by the fact you already have a 10L version. As an aside, after a page of any thread, posts tend to wander.Power density has been addressed. You can increase time, if necessary, but you can't increase size or easily throttle power.The thread then wandered into whether your diluted IPA was the appropriate cleaner. Water alone is sometimes called a miracle solvent. Over time, it can dissolve solid rock and build mountains. In human terms @tooki and others suggested better cleaners depending on what you want to remove. The frequently observed "white residue" probably requires a saponifier (alkaline) remover in water. IPA and absolute ethanol (my personal favorite) are not very effective.Edit: BTW, you are probably referring to a BS in chemistry, not BA/AB degree.

author: SolderOcelot
author_rank: Contributor
timestamp: July 15, 2024, 10:27:54 am
content: Quote from: jpanhalt on July 15, 2024, 10:24:30 amYou could not have worded that in a more powerful and convincing way. Almost poetic.You can increase time, but you can't increase sizeQuote from: jpanhalt on July 15, 2024, 10:24:30 amWere you secretly thinking of dish soap when you typed this? If so, whisper it in my ear and I'll add it to my solution next time.

author: jpanhalt
author_rank: Super Contributor
timestamp: July 15, 2024, 11:17:30 am
content: Quote from: SolderOcelot on July 15, 2024, 10:27:54 amNot Ivory dish soap (https://en.wikipedia.org/wiki/Ivory_(soap)#:~:text=The%20soap%20has%20a%20determined%20pH%20value%20of%209.5.&text=Ivory%20dishwashing%20liquid%20contains%20water,detergent%20instead%20of%20a%20soap). As pointed out (@tooki), it's a soap not a saponifier. Ivory dish detergent (loc. cit.) is different.It is said that Tektronix used to use an ordinary household dishwasher to clean boards sent for repair. I am not sure what it used for detergent. Dishwasher detergents are far more caustic/alkaline than Ivory soap is. This article from Kester discusses its investigation into the "white residue:"https://www.kester.com/Portals/0/Documents/FAQs/White_Residue.pdfIt convinced me. I had found empirically that cleaning a DIY board right away with absolute ethanol was never a problem. Cleaning a SparkFun solderable breadboard immediately was rarely a problem, but after awhile, one would get white residue. I did a project with a commercially made PCB that had a TQFP chip and was done with reflow (Kester leaded solder). White residue was a problem even when cleaned immediately. I tried a DIY water-based remover with ethanol amine as saponifier as described earlier, and the result was great. That convinced me.For cleaning dirt, dust, dead bugs, etc., almost anything in water with a little surfactant activity should work. For flux, you need something different.

author: watchmaker
author_rank: Unknown
timestamp: July 15, 2024, 04:02:01 pm
content: As noted above,yes, hand soap. And the brass brush has to be very soft, like camel hair almost.My favorite supplier closed out on them several years ago and I purchased what I hope is lifetime supply.Cousins in the UK may have them.

author: tooki
author_rank: Super Contributor
timestamp: July 15, 2024, 06:10:39 pm
content: Quote from: SolderOcelot on July 15, 2024, 10:27:54 amAs I already told you: dish soap is NOT a saponifier! Stop fixating on dish liquid, no matter what you've seen "everyone" do.Automatic dishwasher detergent is likely alkaline enough to do the job, but at the expense of possibly being too corrosive. Aqueous, saponifier-based flux removers/PCB cleaners are designed to include corrosion inhibiters and generally be suited for electronics.

author: tooki
author_rank: Super Contributor
timestamp: July 15, 2024, 06:16:07 pm
content: Quote from: watchmaker on July 15, 2024, 04:02:01 pmFor cleaning watches perhaps. But the question is about cleaning PCBs, and for that, hand soap or dish liquid is pointless -- at least if flux is to be removed.

author: CaptainBucko
author_rank: Regular Contributor
timestamp: July 16, 2024, 02:23:46 am
content: FYI Attached is the datasheet and SDS of ChemTools Kleanium Printed Circuit Board & Electronic Parts Cleaning Solution which I have been using with success in my UltraSonic cleaner.

author: jpanhalt
author_rank: Super Contributor
timestamp: July 16, 2024, 10:16:24 am
content: There are lots of similar water-based flux removers with saponifier. The ChemTools product has the same basic formula of a glycol ether and ethanol amine or other strong base. 2-butoxyethanol (and others) is used in other removers and goes by a trademark class name of cellosolve. The later is used at a final concentration of about 10% . I didn't see at first glance whether the ChemTools product is used neat or diluted.

author: CaptainBucko
author_rank: Regular Contributor
timestamp: July 16, 2024, 12:52:12 pm
content: Quote from: jpanhalt on July 16, 2024, 10:16:24 amThey say to use it neat and that is all that I have done. I only put a small amount inside a plastic zip lock bag with the item I want to clean, and then place the sealed bag in normal tap water in the cleaner.

author: SolderOcelot
author_rank: Contributor
timestamp: July 17, 2024, 12:20:26 pm
content: Flux is not my problem by the way. I solely use the ultrasonic cleaner for liquid damage (as in tap water touching electronics while they're powered on) and so to clean the white (iron?) and green oxidation (copper). I don't know if that makes a difference in the recipe. I guess water + saponifier + surfactant is still the way to go?

author: jpanhalt
author_rank: Super Contributor
timestamp: July 17, 2024, 12:47:54 pm
content: If it's oxidative damage to a metal, alcohols are not very good solvents for that. Water + surfactant/detergent is better. I wouldn't try to get too deeply into the chemistry. There are basically two choices water-based and non-aqueous. IPA and ethanol will both have some water, unless you use absolute versions or something like E85, which I do not recommended, but I would consider those alcohols as non-aqueous. Glycol ethers that are in all of the aqueous flux removers have special solvent properties. Using an aqueous flux remover is generally safe and a good cleaner even if flux residue isn't the issue.There is nothing wrong with starting with IPA, though.

author: SolderOcelot
author_rank: Contributor
timestamp: July 17, 2024, 12:50:52 pm
content: @jpanhalt:Interesting, for so long I believed in IPA being undisputed solution for this use case and it was possibly not true.Out of curiosity.. Where did you gain this knowledge around solvents and cleaning? Was it something you picked up in hobbies or was it essential to your work?

author: jpanhalt
author_rank: Super Contributor
timestamp: July 17, 2024, 01:11:29 pm
content: Quote from: SolderOcelot on July 17, 2024, 12:50:52 pmGrad school plus decades of experience. It wasn't necessary to my work, but as they say, you can take a chemist out of the lab but you can't take the lab out of a chemist.

author: SolderOcelot
author_rank: Contributor
timestamp: July 17, 2024, 01:13:08 pm
content: Quote from: jpanhalt on July 17, 2024, 01:11:29 pmOf course not, that would be reverse entropy