Ultrasonic cleaning

The recent article describing the Allendale ultrasonic cleaner gave me food for thought. I have used a little 50 W Aldi model for some time for cleaning my wife's jewellery and have not been very impressed.

I ended up buying a 120 W 3 litre model from Ebay for just under €80 delivered from here

My first test was to clean a couple of watches with expanding stainless steel straps. For the cleaning fluid I just filled the tank with de-ionised water and added 20 ml of general purpose detergent and 10 ml of household ammonia solution. Both watches had been recently cleaned in the Aldi unit and I was horrified to see how black the cleaning fluid became! Obviously the Aldi unit wasn't working very well. A few odd parts with engrained grease were tried after removing the worst with a solvent and came up very nicely.

I have ordered some citric acid to make up a rust removing solution and hope that the results are as good. There are loads of recipes online for suitable cleaning fluids but they don't seem to be critical and making them up is much cheaper than having the supplies shipped from the UK.

Any one else have any good tips?

Russell.

Hi Russell.

I have a 6 litre heated unit from Allendale and use it on an almost daily basis for old lathe parts and anything that is greasy and dirty prior to refinishing.

I use water and a large dash of Fairy liquid. Results are excellent, particularly for getting old paint off, couple of hours on hot and it just scrapes off easily.

Periodically i empty out the 2" of crud in the bottom, wipe out with kitchen roll and run round the tank with a cloth soaked in acetone, comes up like new! Get the basket, really usefull. For small parts I use one of those tiny tea ketle like tea holders and just chuck it in.

If I need to use another solvent I put the in a jam jar with the parts and drop the jar in the water, has the same cleaning effect.

Great bit of kit, I am thinking of getting a bigger size one soon.

Cheers,

Martin

I must admit, I really was taken aback by just how well the Allendale tank cleaned up the castings. the photos really don't do justice to how well it worked.

Neil

I have used a 2.5 litre heated model from Allendale for a long while, and it gets used every time parts are removed from machines.

Good for removing that awful grease that the Chinese smear on all their tooling.

A very good aqueous solution is, 'Micro 90'. Using only a 2% solution it is quite economical. A free 8oz sample can be obtained from the supplier. tel. 0500 345 300. I have used it for many years in an industrial situation and recommend it.

Check the internet for micro 90 to see it in action.

Clive

These are worth looking at if you want something good.

**LINK**

Notice the power input on the quality ones is much higher. The 3 litre Sonorex is listed as 480 watts of ultrasonic power. This is more than some of the 25 litre tanks on ebay so be careful when choosing one.

Frequency also plays a part. The lower the frequency the more aggressive the cleaning 40 Khz seems to be good for general purpose.

One tip as regards cleaning fluid is to us a smaller glass container with the correct fluid in it placed in the main tank filled with plain water. This saves filling the whole tank with expensive fluid.

Also you can test the action of the ultrasonic by using strips of kitchen foil placed at different locations in the tank. The foil should show holes and pitting after 30 seconds or so. All strips should show equal damage.

Regards.

David.

Is it possible to make an ultrasonic cleaner?

Ed.

David Colwill, and Russell

I have a "cheap" aldi/lidl cleaner (I don't remember which one it came from)

If I put tin foil in there, they'd whizz all over the place - it gets quite a buzz going in there, even larger heavier items like keys will buzz and move slightly. I can see bubbles hovering in there too where the water is presumably shearing from the internal forces.

I use (very) hot tap water with a dash of fairy liquid - I've had very good results.

Russell, is your cheap Aldi unit as noiticeably active as this - I'm wondering if yours is a bit of a dud, or if I could achieve even better results with a proper unit.

Regards,

Russ

Well the Transducers and boards are quite readily available, I suspect that producing a successful machine might be more involved than initial impressions would indicate.

The other critical factor might be the overall build costs relative to buying a ready made unit.

I have a small Aldi (I think) Ultrasonic Cleaner, it seems to work well for Jewellery etc.

Edited By V8Eng on 01/10/2016 14:02:54

I work for a company that manufactures ultrasonic cleaning tanks ranging in size from 1 litre to around 500 litres.

The problem you will have is the bonding of the tranducers onto a tank, it is the most critical process in the whole build and uses special adhesives that are oven cured, so I would say to you "don't try this at home"

Phil

Sure - the manufacturers do it the time

Back in the day, Heathkit had a kit for one. I still have mine. They ran into some trouble in Canada (or perhaps North America) with the insulation provided by a power transistor washer and issued an update kit consisting of a beryllium washer replacement (which thought was pushing it a bit).

Many years ago I bought an ultrasonic fog maker in Maplins. At the time I think I paid around £10 for it. They no longer seem to stock this type of equipment but they are still available on ebay. Here is one example priced at £3.99:

http://www.ebay.co.uk/itm/Ultrasonic-Mist-Maker-EU-Plug-Fogger-Water-Fountain-Atomizer-Air-Humidifier-24V-/322118701179?hash=item4affc5507b:g:ljYAAOSwNsdXQsyT

I have used mine on many occasions to clean my wife's jewelry. I just put the fogger in a deep contained with the jewelry and then fill with water containing some detergent. It is amazing how much muck comes out of an expanding metal watch bracelet.

It could be useful for cleaning small parts. I am not sure how resistant it would be to non aqueous solution such as kerosine.

Mike

I think the Maplin type of units are used to make steam effect systems for electrically powered steam locos.

We used to use ultrasonic mist generation units mounted in the AHU as part of the humidity systems in close control environment rooms.

Edited By V8Eng on 01/10/2016 21:16:13

Edited By V8Eng on 01/10/2016 21:22:27

This thread reminded me to dig out an ebay purchase from some time ago, a Walker Ultrasonics unit (110W, about 2 litres I think) which the seller said came out of a dentist's surgery. It had been in a cupboard for a while as I wasn't that impressed when I first got it but never got round to digging into it.

Just tried it again with some hot tap water and washing up liquid. It buzzes away all right but there's little evidence of cleaning beyond what hot water and soap would do anyway. Tried some kitchen foil and it was unaffected after 10 minutes...

Took the bottom off it for a look and the transducer is still stuck to the bottom of the tank. Could that joint nonetheless have failed, explaining the buzz yet lack of cleaning? Or were dental units like this always designed to be rather more gentle than we need for cleaning bits of metal?

Grateful for any ideas to fix/otherwise make it more effective...

You should see a lot of disturbance on the surface of the fluid above each transducer.

A lot of people have un-realistic expectations of what these machines actually do, they seem to expect a grubby old casting to come out nice and shiny. This is not going to happen.

They are very good at loosening engrained dirt from a surface though, if you are cleaning brass parts you can get good results using one of the ammonia based clock cleaning solutions, this will brighten the brass as well as removing dirt (It will do this in any tank, but the ultrasonics speed up the process).

Phil

How do you mean, "unaffected". If you hold it up to the light you should see tiny pinholes (may need a magnifier).

Mmm, after a bit more experimentation all seems well and perhaps indeed some expectation adjustment was in order

Think the main thing confusing me was that with the basket in place the agitation of the water pretty much disappears - just some smooth ripples left. With basket out and less water in the tub then the vigorous agitation of the water as described above is very obvious. Doing the kitchen foil test and holding to the light shows pinholes (mainly on creases) after 30 seconds both with and without basket, so it doesn't seem to change the effectiveness much. Not sure why I didn't see the holes last night.

Just cleaned some oddments and it does indeed work - not quite blasting away rust etc as might have been hoped but it does loosen dirt and grime. Used fairly hot water from the kettle with washing up liquid again - might try some of the other recipes in future. Also, some gentle brushing/poking with an old toothbrush during the cleaning process to remove loose crud seemed to help.

Would probably go for one with a heater if buying again - as well as any cleaning benefit, having the item hot means water evaporates off pretty fast once removed, so less chance of rust.

I'v got a couple of small units, one was used by a beauty and nail therapist for finger nails(? removing artificial nails), the instructions say it must be used with the lid open( from what I can see, the person being treated would have difficulty if it were closed). Both of these little units just seem to buzz at 50Hz.

Ian S C

.

If you're thinking of trading-up ... Please let me know what you want for this one.

MichaelG.

Lets be clear here, the Ultra Sonic cleaning action is by cavitation from the transducer and frequency, the medium is important. Water alone is OK but additional chemicals help lift the detritus and emulsify it ( Hold it in suspension)

Some are degreasing such as watch fluid cleaners and others are detergent. Small parts as said can be put in a glass jar with a small amount of volatile liquid, ie paraffin, white spirit for really dirty parts. Do not contaminate the main liquid by spills.

A lot of cleaning fluids are ammonia based with detergent additions.

Final cleaning is under hot water flow and a warm air drying. Printed circuits can be cleaned but only a short immersion ie. 1 minute whereas in normal materiels 3 to 5 mins. is adequate. careful drying of circuit boards is desired.

Optics can also be cleaned but again a short immersion time. Normal cleaning after with Ether and chamios cleaning sticks.

Clive