Can I use an ultrasonic cleaner on my watch?
Buffy AcaciaWhether you’ve spent hours watching restoration videos or you have a hefty vintage jewellery collection, you’re bound to have heard of ultrasonic cleaners. They’ve been making domestic models since the 1970s, but it’s only in the recent tech boom where they’ve become a staple in many households. You can pick them up for as low as $30, each claiming to remove dirt and grime like magic from the most grimy possessions imaginable. So, can you put your watch into an ultrasonic cleaner? Yes and no, and here’s why.
While putting something into a small bath, hitting a button and having it sparkle within minutes seems like a bit of a miracle, there’s actually some very simple science behind it. You can imagine it like a speaker pressed up against an aquarium, where the vibrations of the sound are pushed throughout the water. Ultrasonic cleaners use a frequency range above human hearing ability, but lower harmonics and vibrations are created, which is what makes that annoying buzzing sound. It’s the microscopic bubbles created by these vibrations which actually clean things, essentially scrubbing them clean without any need for abrasives which might cause scratches. To be honest, it sounds like it would feel amazing to bathe in one. You can also add detergents like dish soap or specialty jewellery cleaning fluids which further helps to break down oils, dirt, and other nasty gunk.
One of the greatest aspects of ultrasonic cleaning is also its greatest hazard, and that’s its ability to get into the nooks and crannies. Anywhere those tiny bubbles can fit will be scrubbed, which lets you clean jewellery of many strange shapes. For watches, or anything else which needs to remain dry on the inside, this could be a death sentence. Even dive watches with hefty water resistances are at risk, because the water’s agitation of the water-resistant seals and gaskets can let some moisture slip past them. You might not even notice it at first, but that moisture would get to work on corroding the movement from within. But, that doesn’t mean it’s impossible to clean your watch with an ultrasonic cleaner.
In order to ultrasonically cleanse your watch safely, you have to dismantle it. This is super easy with vintage watches with press-on casebacks, especially if you don’t need to loosen any screws to remove the crown, and then the movement. You might need a few specialty tools or a friend who would share, but the results can be worth it. After cleaning the case and bracelet, you’ll be surprised how much dead skin and muck hides in the crevices of the lugs, screw-holes and case seams. Not only that, but the surface of the metal will almost appear to be freshly polished. Because human skin is naturally oily, wiping off fingerprints with a microfibre cloth doesn’t actually clean the surface of the case. Layers of grime get deposited over time, lessening the case’s lustre, which is then restored by the ultrasonic waves.
After you’ve retrieved and thoroughly rinsed your watch components, you need to be sure they’re bone-dry before you put the watch back together. Wiping them down with a towel won’t be enough, and could leave enough moisture behind to get started on that dreaded corrosion. I like to leave my cleaned watch cases on a sunny windowsill for as long as possible, but you could also try leaving them in the oven on a very low heat, or find another dehumidifying solution. Once completely dry, then you can put your watch back together and watch it sparkle. It is important to note that water resistant watches can sometimes have their resistance compromised by opening the seals, so you may want to leave it to a professional who can test it again once the cleaning is done if you’re nervous. But, if it’s an older watch whose water resistance can’t be trusted anyway, then there’s very little downside to picking up an ultrasonic cleaner and helping it look the best it can.