Ultrasonic Cleaners – Experiences? Any Good?

[BeagleParticipant @beagle]

Hi all,

I’ve been aware of ultrasonic cleaners for many years, but have never actually used one. At the recent Harrogate Show I saw some for sale and it sparked some interest again.

Does anybody own one, and if so do you rate them? Good / bad points?

In terms of what I’d like to use it for, then its basically the cleaning of pretty much any small mucky parts in the workshop – brake and metal dust and from mountain bike brakes, greasy model servo gears, motorcycle brake calipers, machine parts following stripdown, oily / coked engine parts etc etc. The things that normally take you 2+ hours in the kitchen sink with a toothbrush basically!!

Now I appreciate that they won’t remove tarnish / corrosion, but in terms of simple cleaning of dirt / grease from intricate parts, are they the ‘silver bullet’?

Must you use specific cleaning solutions, or can you still get acceptable results with plain water / drop of washing up liquid? Can you leave the solutions in the tank for months at a time for ad-hoc use, or must they be emptied and dried every time?

Finally, I note that prices vary from ~£20 up to ~£150 for similar sized tank units from various manufacturers. In terms of cleaning performance, do you get what you pay for, or do they all perform similarly and it’s just the name and the shiny stainless housing that justifies extra cost over a cheap plastic model? …Or put another way, is a cheap £20 one for cleaning jewellery going to put a shine to my motorbike sprockets caked in chain lube?!

Cheers all,

– Clive

[BeagleParticipant @beagle]

[adyParticipant @ady]

I’d say a steam cleaner would be better.

 

From mucky car engines to hospital and restaurant kitchens steam always does a good job.

[WindyParticipant @windy30762]

I bought a cheap one from Aldi some years ago and for small delicate articles it did the job.

 

Windy

[Stewart HartParticipant @stewarthart90345]

I got one of those cheap Aldi jobs does the job OK, use it for small parts for engine builds its great for cleaning bits youre goint to fix with adhesive.

 

It will work fine with just water, but I’ve added washing up liquid and swafega to clean real oily/greasey parts

 

Stew

[Clive HartlandParticipant @clivehartland94829]

I have had extensive experience with Ultrasonic tanks in my career.

They are absolutely essential in the manufacture of small instruments and some optical components, in the past they used Freon and CHFC, but these are now banned and in the main only Aqau based cleaners are used.

I will come back to these in a moment,.

The use of Tricorethyline is banned but in the work I do now we use a white spirit pre-wash that gets rid of the dirt and grease, it is then essential to get rid of the white spirit by washing in hot water and detergent. Otherwise it pollutes the ultrasonic tank.

Only then do we put it in the Ultrasonic tank for the final clean. The timings are about 3 mins normally.

The Aqua solution is made up of a 2% solution of a product called ‘Micro’. At this moment I do not have the details of the UK supplier but can post tomorrow with those details. It is very economic and we change it once a week or if the brass bits come out stained.

Micro is used by the US Atomic energy Commision to clean nuclear components so it has a better cleaning residue number than Freon.

Care should be taken at all times to stop pollution of the tank, no dumping of greasy black objects straight into the tank.

I have a tank at work that takes 13ltrs of water and it has a heater and condensing tubes that return vapour back into the tank. We use baskets to contain the items as they are very small sometimes and the oscillations will wear away bits if in contact with the base of the tank.

For your question is it worth it, if you have a continuos flow of work on a daily basis or even weekly then ‘Yes’ go for it.

I found it useful when doing the pre-clean for my Worden before ‘Blacking’.

 

Clive

[Steve GarnettParticipant @stevegarnett62550]

Posted by Beagle on 30/05/2011 09:50:22:

 

Does anybody own one, and if so do you rate them? Good / bad points?

 

Must you use specific cleaning solutions, or can you still get acceptable results with plain water / drop of washing up liquid? Can you leave the solutions in the tank for months at a time for ad-hoc use, or must they be emptied and dried every time?

Finally, I note that prices vary from ~£20 up to ~£150 for similar sized tank units from various manufacturers. In terms of cleaning performance, do you get what you pay for, or do they all perform similarly and it’s just the name and the shiny stainless housing that justifies extra cost over a cheap plastic model? …Or put another way, is a cheap £20 one for cleaning jewellery going to put a shine to my motorbike sprockets caked in chain lube?!

 

Okay, the three points in order:

 

Yes I own one, and for what I bought it for (cleaning small components and printed circuit boards), it’s pretty good. Also we have a larger one at work, although not quite on the scale of Clive Hartlands’ one – same thing, though – excellent for what its used for, which is very similar to what I do at home.

 

Specific cleaning solutions? No, you can use anything suitable. But there are some things you need to be aware of, and these all have to do with bubbles. Ultrasonic cleaning works by a cavitation process (you can read about the details on Wikipedia), but most importantly, you need some form of surfactant (wetting agent) in whatever you use, otherwise the liquid doesn’t make anything like as much contact with what you are trying to clean, regardless of how much you degreased the article first. Also you don’t want to pour liquid fast into the bath, because if you do, you increase the amount of minute air bubbles in it, and this also inhibits the cleaning action considerably.

 

One thing I’ve used that has worked very well is car windscreen wash, straight out of the bottle, or you can dilute it – I wouldn’t go much further than 2:1 though. This contains a surfactant (which is how it cleans your windscreen quickly), and will also degrease things rather effectively, as it also has an emulsifier. As Clive notes, some of the things that you used to be able to use (and were very effective) you simply can’t any more, and sometimes for good reasons. Carbon Tetrachloride used to be used, but since it’s not too difficult to generate your own nerve gas with it, strangely enough it got banned…

 

You can leave a solution in the tank until it’s got too filthy to be effective, and if you are only going to use the cleaner occasionally, leaving the solution in it is actually the right thing to do – every time you pour it, you introduce more air into it. In fact any solution at all that you use should be left to stand for a good while (a couple of days) and then poured very slowly in a laminar flow (ie, no glub glubbing). If you are going to keep liquid in the tank, you should seal up the lid as best you can, though – it will evaporate.

 

Prices, etc. Hmm… I discovered a while back that any cleaner with less than 100W of agitation power is going to take simply ages to do anything useful, and even then the penetration isn’t that good. Having the whole thing made of stainless steel is a good thing, and I wouldn’t worry too much about having one with a heater in – in use the solution will warm up quite a lot anyway in a relatively small cleaner. I’m afraid that you really do get what you pay for with them, though. We have one of these at work which works pretty well (we don’t use the heater). And looking at the current range on Ebay, I’d say that the cost-effective breakpoint for small ones is about the £150 mark. The one thing I’d never do though is purchase one of those ones that look like small toilets!

 

Edited By Steve Garnett on 30/05/2011 11:59:19

[Hugh GilhespieParticipant @hughgilhespie56163]

Back in the ‘good’ old days my first real job was as a deveopment chemist working on ultrasonic cleaners. At the time there was a lot of pressure to switch from solvent based cleaning to aqueous based products. One company I worked with was Viners Cutlery in Sheffield. They had a large trike degreaser for cleaning knives, etc after polishing. I showed them that an ultrasonic bath with a water / detergent solution was just as good at removing the compo. However, they didn’t buy any equipment and it was only years later that I found out why. Apparently there was very strong pressure from tne shop floor to keep the old method as half of the workforce were addicted to trichlorethylene fumes.

[Clive HartlandParticipant @clivehartland94829]

Interesting tale, I worked in a place that had a simple wash bath with Trico. and on a hot day you could see the vapour pouring out over the edge of the container.

One consequence was that your feet got cold! I put a lid on later.

We used it for cleaning the parts of Creed Teleprinters. Oh, and we had no creepy crawlies in the shop, it must have done them all in.

 

When the Freon and Hcfc’s were fazed out I was in touch with Dupont and ICI and both of them were sure that there was no replacement for the Freon in the forseeable future.

Our throughput was at least 80Ltrs a month and it was very expensive. I had a still that would clean up all the waste Freon but I never got 100% back.

 

Later I found out that the Japanese were buying all the Freon and Hcfc that they could lay their hands on, wheather clean or dirty. I often wonder what they did with it?

 

Clive

[BeagleParticipant @beagle]

Guys, thanks for all the replies, loads of really useful info!

 

If I’ve read it all correctly, then in summary; they are an effective and useful workshop addition, although 100+ ultrasonic watt units are probably better for home workshop needs. A heater is not essential as there is some self-heating of the solution in use. Water on its own can be effective for cleaning most things, with addition of cleaners for more difficult to clean items.

 

The minor conflict I’m now having is with the price of the more powerful units. I had hoped to ‘get away with’ a ~ £60 unit, but these typically seem to be about 35-50W, which I guess comes under the probably best avoided category when I consider the types of things I want to clean (I have a filthy motorbike sprocket sat on the shelf ready to test in my aspired new purchase!). I’ll do some digging and see if I can find a unit that fits my price / power needs. Alas, I’ve never bought a cheap tool in my life, so I reckon I can tell which way this is going to end!!

 

As a final query, can you clean really dirty parts within a separate container within the main tank? I.e. could I suspend say a plastic beaker within the main tank (with fluid in of course), then add parts to that, thus contaminating only the fluid volume in the beaker, or does this tend to attenuate the cleaning process?

 

Thanks all – Clive

 

Edited By Beagle on 30/05/2011 22:19:08

[Hugh GilhespieParticipant @hughgilhespie56163]

Clive, I’m digging up very old and probably outdated memories but the ultrasonic tank I used for development work was rated at 750 watts and held about 60 litres. So I would think that you need about 10 – 12 watts per litre of capacity.

 

The way we used to test the tank was to dip in a strip of aluminium cooking foil – Baco foil sort of thing – and measure how long it took to blow holes in it. As I remember, it was usually less than a minute.

 

The coupling between the transducers and the liquid in the tank is important for the most efficient transfer of energy into the cleaning fluid. However, it was easy to get good coupling with tap water with a few drops of washing up liquid. Using different solvents was much more complicated as the coupling was usually pretty poor. A lot of time was spent trying to make good products based on Freons for use in cleaning printed circuit boards after soldering.

 

Regards, Hugh

[Steve GarnettParticipant @stevegarnett62550]

Posted by Beagle on 30/05/2011 22:18:48:

As a final query, can you clean really dirty parts within a separate container within the main tank? I.e. could I suspend say a plastic beaker within the main tank (with fluid in of course), then add parts to that, thus contaminating only the fluid volume in the beaker, or does this tend to attenuate the cleaning process?

 

 

It will probably attenuate it to the point of being useless – unless you can get a plastic beaker that resonates at 40kHz! Most tanks come with a wire cage to lower things in with, but that’s about as far as you can sensibly go with this.

 

Generally if you’ve got something really filthy, you should get the worst of it off with paraffin, or some other suitable solvent as a straightforward wash first. What the ultrasonic cleaner is best at doing is getting to the parts you otherwise simply can’t reach. Whilst it would certainly remove a large quantity of grot, this would almost certainly be counter-productive – you’d contaminate everything else you were trying to clean. It’s slightly different with an industrial one, because you can circulate and filter the working solution, but with a ‘domestic’ one, you don’t get this option unless you somehow arrange it for yourself. And because of the need to keep the fluid flow as laminar as possible, that’s not always so easy to do. Not completely infeasible though – you might be able to do this with a fish-tank pump; I’ve seen ones that do a pretty smooth flow. Trouble with doing this is that unless you’re pretty clever, with filtering you’ll probably need two pumps – one to get it out of the tank and into the filter, and another to get it out of the base of the filter and back into the tank.

 

 

[Steve GarnettParticipant @stevegarnett62550]

Posted by Hugh Gilhespie on 30/05/2011 22:38:38:

Clive, I’m digging up very old and probably outdated memories but the ultrasonic tank I used for development work was rated at 750 watts and held about 60 litres. So I would think that you need about 10 – 12 watts per litre of capacity.

 

The way we used to test the tank was to dip in a strip of aluminium
cooking foil – Baco foil sort of thing – and measure how long it took
to blow holes in it. As I remember, it was usually less than a minute.

 

That would cost a fortune these days! And that is one powerful agitator!

 

A lot of time was spent trying to make good products based on Freons for use in cleaning printed circuit boards after soldering.

 

Nowadays you can get some really good aqueous solutions for PCB cleaning that work excellently with ultrasonic cleaners, but you don’t want to leave your fingers in them for very long – they’ll have the fat out of them in no time. In fact you have to be pretty careful with them, one way or another…

[Steve GarnettParticipant @stevegarnett62550]

Posted by Hugh Gilhespie on 30/05/2011 22:38:38:

 

…the ultrasonic tank I used for development work was rated at 750 watts and held about 60 litres. So I would think that you need about 10 – 12 watts per litre of capacity.

 

Meant to add a bit about that – the figure you need is entirely dependent upon the coupling efficiency of your ultrasonic actuator, and its overall efficiency; I don’t think that the ones currently built into the bases of small cleaners are that efficient. Last time I looked carefully at these ones, the figure was more like 25W/litre at a bare minimum. The other consideration here is that the small tank devices invariably have the actuator outside the tank rather than immersed into the cleaning solution, and I believe that the immersed ones were way more efficient. But also harder to keep that sort solvent-resistant, which is why they generally aren’t done like this any more.

[Clive HartlandParticipant @clivehartland94829]

We do use a small qty of White Spirit in a container to clean out small brgs. Care is taken not to contaminate the aqueous solution and then only for a minimum of time.

The container I let sit in the basket slightly tipped over and it seemes to resonate OK and you can see the fluid turbulating as it cleans.

 

Then the components are washed in detergent and put back into the tank in the normal way to complete the cleaning.

 

Clive

[Clive HartlandParticipant @clivehartland94829]

Here is a follow up on the MICRO-90.Aqueous Cleaning solution.

This is distributed in the UK by:-

 

International Products Corp.

Unit 5

Green Lane Business Park

238 Green Lane

London SE9 3TL 020 8857 5678

 

Web address. saleseurope@ipcol,com

 

Clive

 

[MetalhackerParticipant @metalhacker]

I have had one of the smaller ones for years, which has proved excellent for cleaning glasses (specs), jewellery and the carburettor parts on my model engines and chainsaw. For the greasy lumps, once you have got the major gunk off have you tried the dishwasher (make sure SWMBO isn’t looking). If you avoid lemon scented detergents which discolour ally, they can do a fantastic cleaning job of quite large things. If they are prone to rust however make sure you oil them very soon after removal as they will be ENTIRELY free of oil etc. Works for me!

 

Andries

[John HaineParticipant @johnhaine32865]

One caution (from letters in Horological Journel. DON’T CLEAN BALL BEARINGS in an u/s bath…apparently (at least for the small ones used in clocks) it b*****s thm.

[Jens Eirik Skogstad 1Participant @jenseirikskogstad1]

I has the Aoyue ultrasonic cleaner, 30/50 watt effect. The cheap ultrasonic cleaner works very well. I used the warm water and Allosil cleaning fluid with high pH percent.

 

See this movie i own the Aoyue ultrasonic cleaner: http://www.youtube.com/watch?v=wOlcxZrdCTQ

[Nicholas FarrParticipant @nicholasfarr14254]

Hi all, last Sunday I was in my local Maplins store just browsing, when I spotted a James Ultra 7000 ultrasonic cleaner on offer. Needless to say I bought it on a bit of a whim, just to see what it might do. I realise that many think these are small and not capable of much, but there you go.

 

This morning I have had the chance to try my new cleaner out. I choose to clean a pair of Olympiade loco wheels that my late farther turned up back in the 1940’s, which have become a bit rusty. The first trial was with a 90 second burst in plain water with a couple of drops of washing up liquid followed by a second 90 second burst and a 280 second burst. After these three bursts it was much cleaner and a lot of the rust was removed.

 

 

The other wheel was then cleaned, but this time I used James Sea Clean solution and three bursts of 90 seconds, and the result was very much improved, with most of the rust removed and the greyness of the wheel casting visible.

 

If nothing else is good about small ultrasonic cleaners, at least this one will clean up all the wheels that my late farther turned up all those years ago, without using harsh abrasive methods, time and lot of elbow grease, and especially having to get into all the spokes.

 

Regards Nick.

 

Edited By Nicholas Farr on 08/10/2011 12:02:38

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