You probably just got a new stainless steel bracelet or necklace, and you’re wondering- ‘Is stainless steel waterproof?’
In this article, we’ll explain whether stainless steel can get corroded by water, how the metal is formed, whether you can wear stainless steel jewelry in various wet environments, and how to prevent stainless steel from rusting if it does come into contact with water.
Is stainless steel waterproof?
The unique composition of stainless steel makes it waterproof in pure water and makes it so it can last much longer than several other metals, including gold and silver when exposed to the same corrosive conditions.
To fully understand why stainless steel is waterproof, we need to dive into how stainless steel is formed.
How is stainless steel formed, and does that make it water resistant?
Stainless steel contains varying percentages of iron, manganese, silicon, carbon, nickel, molybdenum, and, most importantly, chromium.
Chromium is so important in producing stainless steel that every grade contains at least 10% of the element.
That’s because chromium is responsible for the waterproof nature of stainless steel.
The chromium in stainless steel reacts with the oxygen in water and air to form a thin, hard, and resistant oxide layer on the surface to make it ‘rust-resistant.’
This layer is a lot slimmer than the wavelength of light, so modern instruments (a transmission electron microscope) are needed to see them.
This makes the underlying metal shine through, hence the name stainless steel.
And because of this layer, there are about 150 different recognized grades of stainless steel, each with different properties and rust resistance.
But just because it is waterproof doesn’t mean stainless steel can’t corrode in other liquids.
Let’s take a look at different wet environments to find out whether you can wear stainless steel in them.
Can you wear stainless steel in water?
Yes, you can wear stainless steel in water, but only if the water is pure and doesn’t contain any extra chemicals.
Although stainless steel possesses a passive layer that makes it more corrosion resistant than most other metals, it is not exactly immune.
Many types of corrosion can attack the passive oxidizing layer at the surface of stainless steel and break through to cause the underlying steel to rust.
The types of corrosion include:
- Pitting – occurrence of pits caused by the localized breakdown of the passive layer due to the prolonged presence of specific chemical species, particularly chloride ion (Cl-).
- Crevice corrosion – lack of oxygen to form and maintain the passive layer on the surface of stainless steel
- General corrosion – Due to exposure to high concentrations of hydrochloric and sulphuric acids, causing the uniform corrosion of the passive layer (and consequently, the underlying steel).
- Galvanic corrosion – occurs when an electrolyte (e.g., salt or detergent) and another metal start an electrochemical process, accelerating the breakdown of stainless steel.
- Intergranular corrosion – chromium combines with the excess carbon content of stainless steel, causing its passive layer to reduce.
- Stress Corrosion cracking – combination of temperature, tensile stress, and a corrosive species (e.g., chloride ion) which increases the rate of corrosion of stainless steel from years to days.
Since none of the types of corrosion mention water, it means water doesn’t pose a risk to stainless steel, and you can wear stainless steel in water.
Can you shower with stainless steel jewelry?
You can shower with stainless steel jewelry, but only if there are filters to absorb some chlorine in the water.
For jewelry made with stainless steel, jewelers prefer the 300 series grade.
Unlike the 400 series (especially the 440C, which rusts faster than the other non-stainless steels), the common 300 series (particularly the 304 and 316 grades) could last for years if placed in the same corrosive conditions.
But do you know what’s seemingly harmless to us but attacks the ‘stainless’ property of stainless steel?
In today’s world, almost everyone bathes with chlorinated water.
That’s because chlorine kills bacteria in shower water by breaking the chemical bonds in their molecules.
Who doesn’t want to be safe from harmful bacteria and deadly diseases??
But chlorine also attacks the chromium oxide layer on the surface of stainless steel, which would speed up its corrosion rate.
So, unless you are sure your shower water contains ZERO chlorine, or you have a filter attached to the shower that filters out a large percentage of the chlorine in the water, you should be careful about showering with things like a stainless steel necklace for example.
Ideally, take off the jewelry before you hop in the shower. If you can’t, or forget to, don’t worry: just rinse with some filtered water and a little bit of detergent and it should be perfectly fine.
Can you wear stainless steel in a pool?
You can’t wear stainless steel in a pool because it could be corroded by chlorine.
In a standard swimming pool, chlorine is added to kill germs that cause diseases such as swimmer’s ear and diarrhea.
As we discussed earlier, free chlorine(Cl2) is very aggressive to stainless steel and would speed up corrosion rate if exposed to it.
According to the Nickel Institute, 304 and 316 stainless steel grades can tolerate up to 2ppm (parts per million) and 5ppm of localized corrosion of chlorinated fresh water.
This data indicates these grades of stainless steel are high quality.
So, if you wear one of either the 304 and 316 grades of stainless steel into a pool full of chlorinated water, you risk it being corroded as you won’t know the amounts of chlorine in the water.
Can you wear stainless steel in the ocean?
You can’t wear stainless steel in the ocean because there are a lot of microorganisms and chemicals that can speed up the metal’s corrosion rate.
Oceans contain salt and traces of chloride ion (Cl-), which react through the electrolysis process.
During this process, ions are absorbed into the surface of the steel, corroding the passive layer, and degrading the quality of the underlying steel.
Not just that, oceans also contain microorganisms.
These creatures interact to produce layers of biofilm (or slime), which creates acidic enzymes.
These enzymes cut off oxygen from the surface of the steel layer, preventing it from rebuilding the passive layer, thereby causing it to erode continuously.
So, you cannot wear stainless steel in ocean water without risking tarnishing the metal.
Caring for your stainless steel jewelry
We’ve learned that although stainless steel is waterproof, it is not immune to corrosion.
There are a few ways to care for your stainless steel jewelry to improve its shelf life.
1) Wash stainless steel jewelry with soap and water
To wash your stainless steel jewelry, you’ll need a non-abrasive cloth, dish soap, a toothbrush, and warm water. Then, follow the steps below:
- Fill two bowls with warm water
- Add about three drops of mild dish soap into the first bowl
- Dip a soft, lint-free cloth into the soapy water.
- Rub the cloth along the jewelry.
- Use a gentle-bristle brush to scrub dirt from tiny engravings.
- Then, rinse the accessory into the second bowl of warm water.
- Use a dry, non-abrasive cloth to wipe the water away.
2) Wash stainless steel with baking soda
To clean your stainless steel jewelry with baking soda, consider the following steps:
- Mix 2 tablespoons of baking soda and a tablespoon of water into a paste.
- Use a soft-bristled toothbrush to scrub the jewelry with the paste.
- Rinse the jewelry with warm water.
- And finally, dry it with a soft towel.
3) Use an ultrasonic jewelry cleaner.
An ultrasonic jewelry cleaner is a tool that combines ultrasound waves and chemicals to create bubbles that remove tarnish and other foreign particles such as dirt and oil.
Ultrasonic jewelry cleaners draw out dirt from the most intricate engravings on stainless steel jewelry, so they are quite efficient.
When you purchase a piece, you can get the steps to use it in the user manual.
4) Store in jewelry boxes or pouches
If you are not wearing stainless steel jewelry, don’t just throw them anywhere because that could cause scratches, especially when in contact with other metals.
So, the best place to store your accessory when you’re not donning it is a fabric-lined jewelry box, or a simple leather pouch, away from other items, especially metals.
If you want to store stainless steel jewelry with gold and silver jewelry, wrap the pieces separately in soft tissue paper.
That way, you can reduce the chances of scratches.
Recap: Is stainless steel waterproof?
Now you know that although stainless steel has a passive, protective layer reducing the corrosion rate by water, and that the layer can still rust due to metal oxides and hydroxides.
But because it forms readily and tightly, the passive layer coating only corrupts/rusts on the atomic level, giving the “stainless” impression.
To answer your question, Is stainless steel waterproof? Stainless steel is completely waterproof.