Stainless Steel Pools: Q&A on Composition and Corrosion Resistance

November 3, 2016 | Categories: Pool Equipment & Systems, Stainless Steel Pools

Stainless steel is by far the most durable and trouble-free material available for use in a swimming pool, spa or aquatic environment. Stainless steel is known for its classic look, strength, hygienic properties and resistance to corrosion. Not to mention they construct buildings, bridges, commercial kitchens and even those fancy appliances everyone wants in their homes.

The life expectancy of stainless steel is measured in a span of decades, not years (which is a good indicator of high-quality material). In order to understand how stainless steel can be used in the aquatic environment, it is necessary to understand the origin of stainless steel and how it chemically responds to certain environmental and man-made conditions.

Below we will answer a few common questions about stainless steel composition and corrosion:


 

What exactly is stainless steel and will it corrode over time?

Stainless steel is a common chromium/nickel alloy steel used in thousands of products from ocean-going yachts to tableware. In most aquatic environments, stainless steel will not rust or stain, even after many years of service.

There are some chemicals that can corrode stainless steel, but these chemicals do not appear in high enough concentrations in pool environments to affect this alloy. When properly installed and maintained, a stainless steel pool will remain rust and corrosion free.

What makes stainless steel corrosion resistant?

The general corrosion resistance of stainless steel is achieved by the use of chromium as an alloying element. The chromium combines with oxygen to form a thin transparent protective film on the surface of the steel. In the case of stainless steel, this oxide film is quite stable and actually protects the steel in normal atmospheric or mild aqueous environments.

Although this protective layer is quite tough, it can be pitted or broken down by the presence of the concentrated halide salts (chlorine, bromine, iodine) used to disinfect pool water. Corrosion can be prevented by implementing a regular cleaning program to prevent the buildup of halide salts on surfaces that aren’t submerged in the water.

How do I clean the exposed stainless steel?

To clean the steel, flush with water and wipe dry all stainless steel railings, bulkhead trim sections, exposed edges of stainless steel gutter systems and other areas that are not regularly submerged. You can also regularly wipe down these surfaces with a soft rag lightly coated with Natare SS SuperClean (our patented stainless steel polish), lemon oil polish or silicone spray.

Does pool chemistry effect the early onset of corrosion? 

Rusting, staining or corrosion problems are almost always linked to chemical concentration or pH. In many pools, chemical levels are frequently too high and chemical consumption is much greater than that required for proper operation. By adjusting these levels to a proper chemical balance, you will greatly reduce the risk of corrosion.

Additionally, the cleaning products and chemicals you use to treat your swimming pool decks and other surrounding areas can also lead to staining or rusting problems if these materials find their way into the pool. Do your best to avoid products that contain or produce halide salts.

 


Do you have a stainless steel pool? What is your regular cleaning and maintenance routine?

If you have more questions, feel free to contact us!

Talk to Natare

8 thoughts on “Stainless Steel Pools: Q&A on Composition and Corrosion Resistance

  1. Tammy says:

    I ya e scale build up on my stainless pool walls. We just had a player job done and now filled with water. What is the best Product to work towards removing the scale? I am keeping ph at 7.2 and brushing daily.

    1. Kayla Kreilein says:

      Hi Tammy! Thank you for reaching out. There could be a few different reasons for your scale buildup. However, since we do not know all of the details about your pool, how it was built, etc., we suggest you discuss the problem with your contractor or installer first. If at that point you do have any further questions, please feel free to contact us.

      I do want to give you one important note to remember and that when you are cleaning the stainless steel pool walls, do not use steel wool or a metal cleaning pad as this could mar the surface.

  2. Zoltan B says:

    I have a stainless steel pool and the salt water sanitizer system has corroded and caused staining on surface. I am planning on going back to standard chlorine or try a new oxygen sanitizer system.
    any thoughts?

    1. Kayla Kreilein says:

      Hi Zoltan,

      Pools with salt sanitizer systems is a very complex topic, but the short answer is that in-situ salt (pools where significant amounts of salt is added to pool water) is a very corrosive environment that will attack virtually all metal components, including stainless steel pool walls, stainless handrails, pumps, heaters, and filter components.

      Even the rebar or wire fabric in concrete and the concrete itself is subject to attack from salt levels in pools.

      Such corrosion is particularly prevalent at the waterline and above where the pool water evaporates and concentrates the salt content. In-situ salt also leaves deposits on pool decks and causes deterioration in some types of ceramic tile and tile grout.

      Natare does not recommend the use of salt in public or commercial pools because of the chlorine demand. Problems can also occur in residential pools unless everything in the entire pool system is plastic. We suggest that you change to a standard chlorination system. Such technology is well understood and is proven to be easily controlled to provide proper pool water chemistry.

  3. joshua wienholt says:

    Stainless steel would be the ideal material if you are choosing for pool materials. Thanks for sharing such informative article.

  4. Todd Christian says:

    We have a small 13,500 gallon pool with stainless steel walls and a concrete bottom. Currently, the system is set up to use the 3″ chlorine tabs. We constantly have low pH and low alkalinity which we understand is typically caused by using chlorine tabs. At our last house, we have a vinyl liner pool with a salt chlorinating system. We’d really like to switch back to a salt system but are concerned about corrosion to the stainless steel walls. Our pool was built in 1985 so have to assume the quality of the walls used are pretty good, since everything else in this fixer upper is very well built and highest quality. Any insight is greatly apreciated!!

    1. Kayla Kreilein says:

      Hi Todd!

      Thanks for reaching out to Natare with your question.

      Natare does not recommend the use of in situ salt systems (where salt is added directly to the pool water) in stainless steel pools. The addition of salt to pool water creates conditions where corrosion to all metallic items in the pool can occur (including pumps, heaters, lights, fittings, rebar in the pool wall, and even the pool structure). The form of chlorine created by such salt systems can cause wide variations in pool water chemistry and is often conducive to electrolysis, galvanic, or stray current corrosion.

  5. concrete pools auckland says:

    I really appreciate you for publishing this blog here about stainless steel in aquatic environments; it’s really a helpful and very useful for us. This is really appreciated that you have presented this data over here, I love all the information shared. Great article!

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