Additional Information

Site Information

 Loading... Please wait...


Smart Advice When Buying a Used Ultrasonic Cleaner

Because new ultrasonic cleaning equipment, especially industrial-sized units, can be pricey acquiring a used unit might be a less expensive alternative. But is it worth it? What do you have to look for to make sure that you don’t spend the money on a unit that does not work well for your purpose or breaks down after only a few weeks of service?

Shopping tips for used ultrasonic cleaners:

used ultrasonic cleaner

First let’s look at what circumstances can damage an ultrasonic cleaning unit. Then we will discuss ways to find out whether a used unit might have been exposed to these circumstances.

There are many things one should not do with an ultrasonic cleaner from The first one is quite obvious: the unit should never have been dropped or otherwise been exposed to brute mechanical force. Ultrasonic cleaning units basically consist of a stainless steel tank, an ultrasonic generator, and ultrasonic transducers that are glued to the bottom of the tank. These components fit into a housing that displays control buttons and other operating information. Many units also contain a heater to preheat the cleaning solution.

Dropping a unit or banging it hard can dislodge ultrasonic transducers from the bottom of the tank rendering the unit useless. If you see a used ultrasonic cleaner for sale that has dents, it is a good idea to look further rather than buying this unit.

Other things that can interfere with the bonding of ultrasonic transducers are heat and the ultrasonic oscillations themselves. Ultrasonic transducers produce a tremendous amount of heat that is usually dispersed by the liquid in the cleaning tank. If the unit is run with a low level of cleaning solution or the cleaning solution is drained before the unit is cooled down enough after a run, heat can damage the bonding between the transducers and the tank, which will prevent cavitation in the tank. Therefore pay attention to any discoloration on the housing of a used unit that might indicate that the unit has been overheated. If there are marks in the stainless steel tank that might indicate low solution level, caution is also warranted.

As mentioned the ultrasonic oscillations themselves can over time deteriorate the bond between the transducer and the tank, so ultrasonic units have a limited life-span. An ultrasonic cleaner that looks obviously very old, might not have much life left.

It is harmful for ultrasonic cleaners to put parts to be cleaned directly onto the tank bottom, as that can damage the parts and the transducers. Therefore, if a used unit is offered without a basket, ask what happened to the basket. If it is offered separately, there is probably no problem. But if it is missing completely, this might be an indication that the unit was used without baskets, and the transducers might be damaged.

Bleach and acids can damage the stainless steel tank, but this damage should be quite obvious as erosion in the tank.

Try to find a unit that includes all the documentation, as otherwise it might be hard to determine the ultrasonic power of the unit. To obtain a high-powered unit might not be essential when trying to clean jewelry, but if you are planning to remove heavy contaminations like paint from paint brushes and air brushes, or grease and other dirt from fishing reels, an underpowered unit will most likely prove unsatisfactory.

Last but not least, once you find a used unit for sale that looks good, does not have dents or discolorations that might indicate transducer damage or overheating, comes with a basket and meets your size requirements, give it a “road test” to see first of all if it works and second if it provides an even field of cavitation. There is an easy test for each of these. Whether the unit cavitates or not can be tested by the glass slide test. Make an “X” with a number 2 pencil on a frosted glass slide. Fill the tank with a warm (50-60oC) soapy water and suspend the glass slide into it (don’t put your fingers into the liquid while the unit is running!). You should be able to see the pencil mark coming off, if the unit is cavitating properly.

Some ultrasonic cleaners might cavitate well in the middle of the tank, but the cavitation field is not even throughout the tank. While this might be good enough if you are planning to clean jewelry that is placed in a beaker in the middle of the tank, it might be very frustrating when trying to clean bigger parts. To test whether the cavitation field is even throughout the tank suspend one inch squares of aluminum foil in the middle of the tank and a few inches from each corner. Running the unit filled with water to the fill line should perforate and wrinkle each aluminum foil square to a similar extent. This indicates that cavitation occurs evenly throughout the unit.


Your information is secure and will not be shared with a third party or spammed