6.5L Ultrasonic cleaner REVIEW

[simonl]

Hi all,

Inspired by the thread by Pete F. on ultrasonic cleaners, I decided to look into the types and sizes and buy one. I opted for a 6.5L size (although that's more a describing size not the actual volume of the cleaning tank) same as this one:
http://www.ebay.com.au/itm/6-5L-Digital-Ultrasonic-Cleaner-Stainless-Mechanical-Jewelry-Watch-Heater-Timer-/131399396776?pt=AU_Business_Industrial_Medical_Scientific_Equipment2&hash=item1e9803ada8

I have since used it a few times and been reasonably happy with the results. Initially I was a little disappointed but that was a consequence of loading it up with too many parts. In operation, it's surprisingly noisy, sounding more like an electric chair in use! The heating function is useful but given it's only 300W of heating, it takes quite a while to heat the volume of water to (say) 50 deg. In fact, if you set the ultrasonic cleaner to run for 15 mins and select 50 deg on the heater, you will be wasting your time if you think it will heat to that temp within the selcted cleaning time. I have found the best way is to preheat the water either by using hot water from the tap, or run the heating function separately for 20 mins to reach the desired temp and then start the cleaning.

The drain tap on the side is a nice addition. It saves having to tip the whole unit to empty. Unfortunately the flow is not the greatest and so tends to leave the gunk that you cleaned off sitting on the bottom of the tank anyway. The actual ball valve looks to be of good quality. Seems like a "normal" ball valve that you would see on a pressurised system and not just some cheap irrigation valve that leaks even with gravity pressure.

The unit looks pretty well made and all parts line up and mate together nicely. It has rubber feet on the base and a PC fan for cooling. I have noticed that some ultrasonic cleaners do not have a fan in the base. This particular unit allows times of up to 90 minutes for cleaning, although in the instruction manual it says not to run it for more than an hour at a time.

It comes with a basket that sits inside the tank. This (as you would guess) is where you place your parts. It's quite light duty but seems to perform the task quite well. Looks more like a deep fryer! It does the job at holding larger parts but for smaller items like nuts, bolt etc. you really need to make a further purchase of a small parts holder like these:

http://www.ebay.com.au/itm/ULTRASONIC-CLEANER-BASKETS-SET-of-2-Pcs-STAINLESS-MESH-SMALL-PARTS-HOLDER-MINI-/220957047284?pt=LH_DefaultDomain_0&hash=item337210f9f4

Although I have been known to use a tea bag holder as well.

Unfortunately, yesterday I went to use my cleaner and found that the tactile switches for the time select function on the ultrasonic cleaner had given up on me! :(( I promptly sent an email to the seller (Based in Sydney) and they replied very promptly. They requested some photos and a video of me pushing the buttons and seeing the fault, which I did. They were very appologetic and assured me that they will work to fix the issue.

Another email later and they said they will supply another tactile front sheet and detailed instructions on how to replace it. I figured this was a good opotunity to take the thing apart and have a look, afterall, that's what the supplier wants me to do!

So, I proceed to unscrew the 10 small screws that hold the base onto the body and lift off the base. The main driver board for the ultrasonics are attached to the inside of the base and cooled with the fan. The board seems quite well made and the wiring from the board is routed nicely with cable ties to both the 3 ultrasonic transducers and to the board that drives the timer and heat functions.

The ultrasonic transducers are bigger than I imagined. They seem well attached to the underside of the tank with generous amount of adhesive compound. The drain and plumbing are also well installed. The ball valve is obviously stainless and looking at the inside, it can be seen that the entire plumbing is all stainless. I was surprised at this. It too all looks well jointed and sealed for long life.

The plastic moulded lifting handles on each side of the tank screw in from inside, they also have a sealing compound to prevent loosening. The top of the tank has a lip that protrudes over the sides, this lip is also sealed all the way around, preventing any spilt liquids from getting into the inside.

As mentioned, the tactile switches are the only thing that let this unit down. I remember somone mentioning in Pete's thread that they would purchase a unit with manual dials so that it would be easily fixed. I don't really see this as a deal breaker, the self adhesive sheet at the front comes off with ease and it attaches to its driver board with a connector through a neat pre punched hole in the panel. Millions of these tactile type switches are used everyday on appliances, I guess some must be faulty. I had thought about replacing these tactile switches with a small IP rated mom switch attached to the front panel but I will see how the replacement performs. Either way, if the tactile switches crap themselves, it does not mean it's a throw away unit.

So, overall I'm happy with the unit. A bit disappointing about the switches but it could happen to anything.

Edit: the inside of the tank measures 150mmx150mmx300mm and so about 6.7L however given that you need to use the basket, it reduces the useable size to about 4L. So, if you are counting on the volume, you really need to look at a bigger size.

Anyway, I hope this has been of some interest to people here.

Cheers,

Simon

[simonl]

http://tapatalk.imageshack.com/v2/15/01/15/b7af132dbd41454b538a2516edce7c92.jpghttp://tapatalk.imageshack.com/v2/15/01/15/6318406f1489501d6dd9e8a2d00a0551.jpghttp://tapatalk.imageshack.com/v2/15/01/15/2c7b6b239e462617718dd7855016ac6d.jpghttp://tapatalk.imageshack.com/v2/15/01/15/c66c76f25e7905a665733e37cc627779.jpghttp://tapatalk.imageshack.com/v2/15/01/15/0957c759cd57c06a081edee419a9d2c4.jpghttp://tapatalk.imageshack.com/v2/15/01/15/a230419ca7a1fb58709a45088d77cfca.jpg

[chambezio]

Simon,....just a question about the liquid that you use. Is it an appropriate solvent? Degreaser, kero, thinners?

[simonl]

Simon,....just a question about the liquid that you use. Is it an appropriate solvent? Degreaser, kero, thinners?

You have several options. Just plain water, water with a drop of detergent such as dish washing liquid (what I use) or a dedicated ultrasonic cleaning agent. I have not used any dedicated cleaning agent but on one accasion I did use some degreaser. Probably not a good idea since it's caustic and it left the tank with some mild corrosion. This scrubbed out OK but if used regulaly I dare say it would reduce the life of the tank. I have also been told that the ultrasonic waves create bubbles on the surface of the part which when implode create very high temperatures and if incorrect slovents are used then it can cause pitting on the surface of the part. Can't be sure as to the validity of this, maybe someone can confirm or deny (about the pitting part anyway)

The temperature of the water seems to make the single biggest difference. Water temps of 50 - 60 degrees has a marked improvement over cold water. That doesn't mean you need an ultrasonic cleaner with a built in heater, you just need to use hot water at the start. Also note that the heater in this unit switches off once the temperature has been reached and does not come back on to maintain the choosen temp. So it's not like it cycles on and off to maintain the selected temp. In this respect it's no different to using hot water from your tap. In any case, cleaning cycles of 15 - 20 mins are not going to see your liquid cool by much.

Edit: I don't think I'd be keen to use any solvent that is flammable (unless it's diluted so it increases it's flash point about about 100 deg) . I'm keen for someone else to have a go and post the video though! :2tsup:

Hope this helps,

Simon

[chambezio]

In terms of performance......can a greasy/dirty part be "clean" in the 20 minutes?

[BobL]

Simon,....just a question about the liquid that you use. Is it an appropriate solvent? Degreaser, kero, thinners?

US Solvents are discussed in detail in this thread
http://www.woodworkforums.com/showthread.php?t=189809

Simon, your experience with the tactile switches is exactly why I purchased an US cleaner with simple analog switches and old school pots.
The old versions are easily fixed and I just hate having to hold my finger on those push button type switches until they reach the required value.

[simonl]

TBH im yet to clean anything thats absolutely cacked with filthy grease. I suspect that a small unit like this may take several applications. Only used it a few times but I suspect its good at getting mildly dirty parts really clean. One of its advantages is being able to clean the internals of parts that you would not normally be able to get to.

Nothing saying you cant zap the part for an hour at say 60 deg using generous amount of detergent.

When I get home ill see if I can find something really filthy and ill report back with before and after pics.

Simon

[Stustoys]

Edit: I don't think I'd be keen to use any solvent that is flammable (unless it's diluted so it increases it's flash point about about 100 deg) . I'm keen for someone else to have a go and post the video though! :2tsup:

On mine I find the heater cycles but its only needed to maintain the bath temp while the ultrasonics are off.

I mostly use Kero in mine, its yet to explode though may not be the best idea ever. Not sure it works any better(or even as well), but I'd rather not be using water, though I have.

Stuart

[simonl]

Hi Bob. I think it may have been you that I was refering to regarding the switches. I cant blame you, im not a keen fan of them either.. now. But like I said they too are easily replaceable with simple mom buttons. In fact that whole timer module is easily replaced as all it does is power on and off the US driver board. You could replace that with a simple mechanical timer and it would make it like yours. Easier to just buy one like yours though!

Simon

[simonl]

Hi Stuart. So Kero works ok? May have to give that a go. Assume it works better than just water and detergent?

WRT water, I have found that if you use hot water and set the temp to 60 - 70 degrees, the part dries very quickly and shows no sign of rust. I guess most of the parts I have cleaned have been from a 50 yo SG and so not really an issue!

Simon

[Stustoys]

Hi Stuart. So Kero works ok?
Seems to


Assume it works better than just water and detergent?
I haven't done any side by side testing, so couldn't say.(though I wouldn't be surprised to learn detergents work better)


WRT water, I have found that if you use hot water and set the temp to 60 - 70 degrees, the part dries very quickly and shows no sign of rust. I guess most of the parts I have cleaned have been from a 50 yo SG and so not really an issue!
Yeah I haven't tried cracking the temp up that high. If I ever get myself set up again I'll revisit water for sure. Its more about how clean the finished item needs to be. If I'm cleaning something like a mic, I'll play around with multiple washes, rinses then drying and oiling. For machine parts its just into the kero, then I've no need to worry about how long its in there, drying it or oiling it after its dried.

Stuart

[simonl]

Stuart, what sort of US cleaner have you got? Knowing you its probably a wizz bang unit big enough to wash a large dog?!

Simon

[BobL]

Here's a list of solvents I have used in USCs over the years.

Plain Water
Water/detergent (only a very small amount of detergent like 1 small drop per litre is sufficient)
metho and other various alcohols
Kero
Carby cleaner (toluene/metho/acetone mix)
Turps
Acetone
Toluene
Chloroform
Dichloromethane
Nitric acid
Acetic acid.
There were probably others but I cannot remember them
In all cases, the solvents and parts were in glass or SS container inside the USC water bath.
Good ventilation is required for most of these as the USC action heats and vaporises the solvent.

We used to start the dissolution process of small amounts of mineral grains rocks and meteorites using some very nasty acids like hydrofluoric acid. The materials and solvent were contained inside 15 cc sealed screw top teflon containers, sitting in a water bath in a USC. What used to take a couple of days on some minerals would happen in 20 minutes using the USC. Then placing the teflon containers in a microwave oven for a few minutes and most minerals were toast.

[Stustoys]

Stuart, what sort of US cleaner have you got? Knowing you its probably a wizz bang unit big enough to wash a large dog?!

Sorry to disappoint you..... its appears to be pretty much the same as yours, only the 2l version :no: lol

Damn Bob, and I thought isopropyl alcohol was living on the edge lol

Stuart

[Greg Q]

When I had a similar sized unit I used to put items needing degreasing inside a glass jar with solvent and immerse that in the water of the ultrasonic. Made for a easy clean-up and you get to reuse the solvent. The sound waves pass through the glass no problem and seem to create more fizz in the jar than in the tank.

Greg

[simonl]

Thanks Bob, theres a cocktail of different chemicals in that lot! Looks like I really do need to experiment with more than just water.

Disappointing Stuart!

Greg, that's a great idea. I never even thought of that but it makes sense. Sounds waves travel through dense mediums so glass would work well. Great for small items. I'll try that.

Simon

[BobL]

Here's another chemical that can get improved results in an US cleaner.

I have been taking apart a non-operating 90cc Chainsaw powered concrete cutting saw and most of the 6mm hex screws holding it together were greasy, rusty and/or crudded up with cement. Some of the hex screw sockets were full of cement and to get these out I ground a fine chisel end onto an old chainsaw file and that enabled me to chip out enough of the cement to insert a hex key, but now I faced with how to clean them up.

Here is a close up of what some of the screws looked like.
This is the batch that got US with CLR.

http://www.woodworkforums.com/attachment.php?attachmentid=337209&stc=1

All of the standard concrete/cement cleaners involve some form of acid but as some of the screws still had a zinc coatings and I wanted to lose as little of this as possible. Then I remembered CLR gets calcium, lime and rust stains off various things and when I looked this up I see it contains 30% Lactic (a weak) acid and a wetting agent, so I thought his cleaner might not remove too much of the Zn provided I did not expose the screws for too long.

The instructions on the CLR container call for use from "neat", to an 8:1 dilution with water, for 2 minutes before washing it off

This is what a selection of the bolts looked like before the test.
http://www.woodworkforums.com/attachment.php?attachmentid=337210&stc=1
I divided the screws into 4 groups of ~7 stews and the plan was to subject these to various cleaning by
water (soak only), water in the US unit, CLR (soak only) and CLR in the US

I ran the test for 3 x 2 minute intervals (total of 6 minutes) until at least one of the batches were clean
http://www.woodworkforums.com/attachment.php?attachmentid=337211&stc=1

Of course I didn't expect a water soak would do much which it didn't.
Using Water in the US did nearly as good a job as the CLR soak.
The long screw in the CLR&US batch was very greasy and rusty and could be improved on.
It's likely I could have got the good results with a much longer CLR soak but I did not want to lose any more zinc.
A longer water & US might have removed more of the cement but is unlikely to remove much more of the rust

I have no idea how much zinc was removed by the CLR but it looks like most of it is still there - I will now leave them for a few days and see how much they rust.

A similar chemical that might be worth a try for such a circumstance is very dilute vinegar.

[simonl]

Here's another chemical that can get improved results in an US cleaner.

I have been taking apart a non-operating 90cc Chainsaw powered concrete cutting saw and most of the 6mm hex screws holding it together were greasy, rusty and/or crudded up with cement. Some of the hex screw sockets were full of cement and to get these out I ground a fine chisel end onto an old chainsaw file and that enabled me to chip out enough of the cement to insert a hex key, but now I faced with how to clean them up.

Here is a close up of what some of the screws looked like.
This is the batch that got US with CLR.

http://www.woodworkforums.com/attachment.php?attachmentid=337209&stc=1

All of the standard concrete/cement cleaners involve some form of acid but as some of the screws still had a zinc coatings and I wanted to lose as little of this as possible. Then I remembered CLR gets calcium, lime and rust stains off various things and when I looked this up I see it contains 30% Lactic (a weak) acid and a wetting agent, so I thought his cleaner might not remove too much of the Zn provided I did not expose the screws for too long.

The instructions on the CLR container call for use from "neat", to an 8:1 dilution with water, for 2 minutes before washing it off

This is what a selection of the bolts looked like before the test.
http://www.woodworkforums.com/attachment.php?attachmentid=337210&stc=1
I divided the screws into 4 groups of ~7 stews and the plan was to subject these to various cleaning by
water (soak only), water in the US unit, CLR (soak only) and CLR in the US

I ran the test for 3 x 2 minute intervals (total of 6 minutes) until at least one of the batches were clean
http://www.woodworkforums.com/attachment.php?attachmentid=337211&stc=1

Of course I didn't expect a water soak would do much which it didn't.
Using Water in the US did nearly as good a job as the CLR soak.
The long screw in the CLR&US batch was very greasy and rusty and could be improved on.
It's likely I could have got the good results with a much longer CLR soak but I did not want to lose any more zinc.
A longer water & US might have removed more of the cement but is unlikely to remove much more of the rust

I have no idea how much zinc was removed by the CLR but it looks like most of it is still there - I will now leave them for a few days and see how much they rust.

A similar chemical that might be worth a try for such a circumstance is very dilute vinegar.Thanks for the info and pictures Bob. This thread has generated more info than I expected. Cheers, Simon