A customer asked how to clean her sterling silver jewellery in an ultrasonic cleaner
Even quality sterling silver, no matter where it was bought, can get those ugly black marks that spoil the appeal of expensive jewellery. After working in the jewellery trade for more than 3 decades we can say that this is a very common occurrence. The ultrasonic cleaner will clean contaminants very well, but it will not remove tarnish on its own.
Here’s a hint for handling tarnish and this is the way we handle it ourselves when we have a piece so affected
- Teaspoon of ammonia in the tank with the water.
- Run jewellery through a single cycle. Do not throw out tank solution yet.
- Inspect jewellery. If still not properly treated leave the item to soak in the solution – just as it is for say up to 30 mins. Do not throw out tank solution yet.
- Inspect again. If still not to your satisfaction next step is to grab an old furry toothbrush. Wrap a soft cloth around the bristles. Dip brush in the tank (still with the ammonia solution). Gently rub the section that is tarnished. In our experience this will get rid of the tarnish 99% of the time. For the other 1% – try upping the concentration of ammonia and repeating the procedure from 3 above.
For best results rinse item using distilled or filtered water. Domestic tap water will almost always contain some level of lime and scale which dries to form a messy film. Not a good look on your jewellery.
- Tarnish is not contamination. it is a reaction between oxygen in the air and the metal of the jewellery, similar to rust in ferrous based metals. Ultrasonic cleaners can remove loose particles but they can not convert oxidised metals to shiny metal without an additive.
- Rusted metals, or equipment to be cleaned after exposure to marine environments will respond best to additives such as SALT X. Used in conjunction with ultrasonic cleaning, SALT X will help reverse and prevent salt water corrosion, making it ideal for maintenance of SCUBA and fishing gear.