While we don't always use ultrasonic cleaner during the post-cleaning process, there are situations where it can be convenient:
1) Models with lots of deep recess and hollows that are hard to reach
2) Lots of small models that would take too long to do by hand
3) Working with resins that are easy to wash
4) You need to clean at a higher temperature
Ultrasonic cleaner heats up during operation even without a built-in heater, which helps with cleaning but poses a problem when using a flammable solvent like 90% IPA. This is particularly a dilemma in winter where some locations can experience below 10C temperature that will significantly reduce cleaning performance of alcohol but warming up alcohol also poses a fire hazard.
What do we do here?
NASA Scientists proposed using plastic bags
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19690000520.pdf
This prevents the flammable vapor from escaping while still getting the benefit of ultrasonic cleaning. In this scenario, you can likely improve cleaning by getting the water temperature up to 30C.
What is your cleaning approach with ultrasonic cleaner? Share with follow users in our Discord server or Facebook page,
5 comments
Brant
Did Tibor just say that the cleaner is going to shoot a spark fireball through the full metal bin? What kind of bin would be used in an ultrasonic cleaner that can “shoot a spark of electricity in the tank?” My tank is a full pressed metal basin with a metal lid. No electricity will be in the tank when it is properly grounded. Caution and good sense should rule. A bag of IPA can ignite as easily as IPA in the tank. If you are worried, watch the temp in the tank. I put IPA in a bag sometimes because I don’t like using that much IPA.
anthony
YES or NOT ? to Tomaz question
Hi, thank you for this useful solution, can I also use closed glass jar instead of plastic bag?
Tibor
Ig: the transducer in the ultrasonic cleaner has a lifespan, and when it fails it may shoot out a spark of electricity in the tank. So if the tank is filled with flammable liquid like IPA, you just firebombed your home. With water thats not an issue. The plastic bag method is a safety precaution.
Tomaz Glisovic
Hi, thank you for this usefull solution, can I also use closed glass yar instead of plastic bag?
ig
Why is IPA even considered dangerous with Ultrasonic cleaners? US cleaners do heat up liquid, but never so much to set IPS on fire. Is the concern mostly about extra evaporation due to higher temps?