Hey, friend! Ever see a dirty bike chain or a dull ring? Ever think, “I need a magic cleaning box!”? Ultrasonic cleaners are almost that. They clean really well. They blast away dirt from tiny spots. This makes them great for many things, like jewelry. But, they’re not for everything. I learned this the hard way. You don’t want to make my mistakes. Many people don’t know what not to put in an ultrasonic cleaner. This can cause real damage.
This article is your guide. It’s like a chat about things you should never put in an ultrasonic cleaner. We’ll talk about why. This way, you can use your cleaner safely. You’ll avoid sad (or costly) problems.
How Ultrasonic Cleaners Work: It’s All About Cavitation
First, let’s see how these things work. It’s all about cavitation. Picture this: The cleaner sends out sound waves. These waves are super high. We can’t hear them. They go through the water (or cleaning mix). These waves make lots of tiny bubbles. These aren’t like bath bubbles. These bubbles hit the item you’re cleaning. Then, they pop!
That pop makes a strong scrub. It’s like tiny scrub brushes on every spot. This is why these cleaners are so good at cleaning hard-to-reach areas. But, here’s the key: that scrub is strong. That force makes some items a big no-no for these cleaners.
Read also: Guide to Clean coins with ultrasonic cleaner
What NOT to Put in an Ultrasonic Cleaner?
Let’s get to the main point. Here’s what to avoid, and why.
Delicate Items and Loose Parts
Think of anything fragile. Or, think of things with tiny parts that could come off. These are usually not good for the cleaner.
- Jewelry:
- Safe: Hard metals like gold, platinum, and silver are usually okay. But, they must not have soft stones or glued parts. Plain wedding bands are often fine. So are solid gold chains.
- Unsafe: This is important. Avoid these:
- Soft stones: Pearls, opals, emeralds, turquoise, amber, and coral are soft. They can crack. The vibrations are too strong.
- Porous stones: Malachite and lapis lazuli can soak up water. They can also soak up the cleaning mix. This can cause damage or color change.
- Heat-treated or fracture-filled stones: Many gems are treated. This makes their color or clarity better. The cleaning process can make cracks worse. It can also change the color.
- Loose stones or glued settings: The shaking can loosen stones. It can also melt the glue. This can lead to lost gems! I’ve heard bad stories about this.
- Watches:
- Safe: Only very waterproof watches with screw-down crowns might be safe. Even then, be careful. It’s best to check what the maker says.
- Unsafe: Say no to watches that aren’t waterproof. Also, avoid watches with leather or fabric bands. Never put mechanical watches in. The shaking can mess up the tiny parts inside. Water can get in and cause rust. It is not good ultrasonic cleaning safety.
- Eyeglasses/Sunglasses: The shaking can harm the lens coatings. It can also loosen the frames. It is not one of the ultrasonic cleaner best practices.. Use a soft cloth and lens cleaner instead.
- Other: Be careful with dentures. Some are okay, some aren’t. Ask your dentist! Never put antique items with fragile parts in the cleaner.
Items Made of Certain Materials
The material matters. It doesn’t matter what shape the item is.
- Wood: Wood has tiny holes. It’s porous. The ultrasonic cleaner pushes water in. It also pushes the cleaning mix in. This can make the wood warp, crack, or rot.
- Rubber: Most rubber items are not good. The heat and shaking can ruin the rubber. It can make it brittle or sticky. Some special rubber parts are made for this cleaning. But, unless you’re sure, don’t do it.
- Ivory: Ivory is very brittle. It can also change color. The cleaning process will likely harm it.
- Certain Plastics: Some plastics can get brittle. Others can change color. This is more common with older or cheaper plastics.
- Anodized Aluminium: Ultrasonic cleaning machines can strip away its protective coat.
- Painted Items: Paint might come off or get damaged.
Items with Embedded Electronics
This should be clear, but we’ll say it:
- Phones, Tablets, Computers, etc.: Never put these in an ultrasonic cleaner! Water and shaking will ruin the parts inside.
- Circuit Boards: Only clean these if they are made for it. They also need to be prepared the right way. This usually means special coatings.
Flammable and Corrosive Substances
This is about staying safe. It’s also about keeping your cleaner safe.
- Flammable Liquids (Gasoline, Alcohol, Solvents): This is a very big no-no. The cleaning process makes heat. Putting these liquids in an ultrasonic cleaner can cause a fire or a blast. Don’t do it!
- Corrosive Substances (Acids, Alkalis): Strong acids and bases can harm the cleaner’s tank. They can also cause bad chemical reactions.
Items that have been in the Pickle Pot
In jewelry making, “pickle” is a mix used to clean metal after soldering. Never put items with pickle on them in an ultrasonic cleaner and do not use it as an ultrasonic cleaner solution. The pickle can ruin the machine. It also won’t clean well.
Bicycle Parts
Many metal bike parts can be cleaned. But, be careful.
- Exceptions: Solid metal parts like chains and some cassettes are okay. But, rinse and dry them well after.
- Do not put in parts with bearings. Anodized aluminum is also easily damaged.

Ultrasonic Cleaner Operating “Don’ts”
It’s not just what you put in, but how you use the cleaner that matters. Here are some key things to avoid:
Never Place Items Directly on the Tank Bottom
Think of the bottom of the tank as the source of all that cleaning power. If you put your items directly on it, you’re blocking the sound waves. This stops cavitation from happening properly. It also creates a risk of damaging both your item and the cleaner itself. Always, always use a basket or tray. This lets the sound waves move freely around your items.
Maintain Proper Solution Levels
Your cleaner will have a “fill line.” Pay attention to it! If the solution level is too low, the cleaner won’t work as well. Worse, it can actually overheat and damage the internal parts. It’s like running a car engine without enough oil – not a good idea.
Use the Correct Cleaning Solution
Water-based solutions are the way to go. Most ultrasonic cleaners are designed for them. Also, a pro tip: “degassing” is important. What’s that? It means running the cleaner for about 10 minutes before you put your items in. This gets rid of air bubbles in the solution. Those air bubbles can block the sound waves, reducing cleaning power. A good degreaser for ultrasonic cleaner will have instructions.
Don’t Overload
It is important to not put too many things into the machine. It is best practice to let the ultrasonic cleaning machine do the work with limited items.
Check the Maximum Temperature
High temperatures will speed up the process. But it can also damage some items. So, check the manual to get maximum temperature.
How to Test Your Ultrasonic Cleaner (Aluminum Foil Test)
Want to make sure your cleaner is working right? There’s a simple test you can do, it is named the aluminum foil test:
- Get a piece of aluminum foil. It doesn’t have to be big, just a few inches square.
- Fill your cleaner with water (and solution, if you’re using it). Make sure it’s at the correct fill line.
- Hold the foil vertically in the water. Don’t let it touch the bottom.
- Turn the cleaner on for about three minutes.
- Take the foil out and look at it.
What should you see? If the cleaner is working well, the foil should have lots of tiny dimples or even small holes. This shows that cavitation is happening. If the foil looks mostly smooth, there might be a problem.
Alternatives to Ultrasonic Cleaning
So, what if you can’t use an ultrasonic cleaner for something? Don’t worry, you have options!
- Good old-fashioned hand washing: Mild soap and warm water, along with a soft brush or cloth, works wonders for many things.
- Specialized cleaning cloths: Microfiber cloths are great for eyeglasses and delicate surfaces.
- Jewelry cleaning solutions: There are dips and solutions specifically made for different types of jewelry.
- Professional cleaning: For valuable or delicate items, consider taking them to a professional (like a jeweler or watch repair specialist).
FAQs
Here are some FAQs, written in a conversational, friendly, and highly readable style, keeping the answers concise but informative:
Q: Can I put jewelry in an ultrasonic cleaner?
A: Hey, it depends! Solid gold and silver are usually okay. But, skip anything with soft stones like pearls or opals. They can crack! Also, no glued-in gems. The shaking might make them fall out.
Q: Is it safe to clean my watch in an ultrasonic cleaner?
A: Only if it’s really waterproof. And I mean really! Like, it has a screw-down crown. Even then, be careful. Never put a watch with a leather band in. Mechanical watches are a no-go, too. The tiny parts inside can get messed up.
Q: What about eyeglasses? Can I use an ultrasonic cleaner for those?
A: I wouldn’t. The shaking can mess up the coatings on the lenses. It can also make the frames loose. It is better to clean with soft cloths.
Q: Can I use alcohol or gasoline in my ultrasonic cleaner?
A: No way! That’s super dangerous. It could cause a fire or even a blast. Always use a water-based cleaning mix. It will keep the machine damage free.
Q: I have a rusty old bike chain. Is an ultrasonic cleaner good for that?
A: Yes, it can be! A grimy chain is often fine in an ultrasonic cleaner. But, make sure to dry it really well after. Then, oil it right away.
Q: My friend told me not to put anodized aluminum in. Is that true?
A: Your friend is smart! Anodized aluminum can get damaged. The ultrasonic cleaner can strip off the coating.
Q: Can an ultrasonic cleaner remove firescale after soldering?
A: No, It cannot. Items that is full of pickle solution, you cannot clean.
Q: Can I put wooden items in an ultrasonic cleaner to clean?
A: No, friend. Wood can soak up the cleaning solution. It can be damaged.
Conclusion
Ultrasonic cleaners are amazing tools. They can make cleaning fast and easy. They get into all those tiny spaces. But, they’re not magic. You need to know how to use them right.
Here’s a quick recap:
- Always use a basket.
- Fill to the correct level.
- Use a good cleaning solution. Don’t use bad stuff like gasoline.
- Never put in delicate items.
- Never put wood, most rubber, or electronics inside.
The biggest takeaway? Hope by reading this article now you know, what NOT to Put in an Ultrasonic Cleaner. Be careful! Always think twice before putting something in your ultrasonic cleaner. Do a little research. It’s better to be safe than sorry. You don’t want to ruin your favorite things, do you?
Now, I’d love to hear from you! Have you had any good (or bad!) experiences with ultrasonic cleaners? Share your stories in the comments below! Let’s learn from each other.

I love all things tech, and I wear many hats – tech lover, business starter, digital marketer, and blogger. I know the ins and outs of Digital Marketing, SEO, SEM, SMM, and how to generate leads. My goal? Making things simple for you with clear guides and reviews. I stumbled upon WordPress while creating my first business site, and I fell in love with it right away. When I’m not building websites, creating content, or boosting clients’ online efforts, I’m focused on staying healthy, hanging out with family, and exploring the world. Connect with me on Facebook, Twitter, Linkedin, or read my complete biography.