Protect your pool from corrosion: An essential guide

Any pool built by specialized pool designers and builders will be prepared to withstand continuous exposure to water, chemicals and air. The combination of these external elements, over a long period of time, can still start to chip away at the quality of stainless steel elements, unless this is addressed correctly. On the other hand, pool panels are exposed to highly chlorinated environments inherent to the technical room.

Corrosion is one of the issues most often encountered by pool operators or owners, since it comes about through combining three elements that are essential in operating any swimming pool. When the metal parts of a pool come into contact with water, chemicals (such as chlorine), and air (oxygen), the metal starts to oxidise. Over time, this weakens it and creates rust. Which is known as corrosion.

Its effects can be severe, not just causing significant damage to pool panels and leading to costly repairs, but also potentially raising safety issues. High levels of corrosion in commercial pools can put public safety at risk, due to unhealthy issues and the weakened structures, which can collapse and cause accidents.

Types of corrosion

Swimming pools are attacked by two types of corrosion: galvanic and electrolytic.

• Galvanic corrosion takes place when two different metals come into contact with an electrolyte, such as water. The less noble of the two metals will then corrode.
• Electrolytic corrosion occurs when an electrical current passes through the water — this causes metal components to corrode at a faster speed than they would otherwise.

Signs of corrosion include rust, discoloration, pitting, and cracking on the pool panels. As soon as any of these signs become evident, pool operators should contact a professional to assess the damage and plan out next steps. It is imperative to act immediately in order to prevent further damage.

Stainless steel is one of the most reliable materials if you want to avoid your pool acessories (such as stairs, railings, water jets, etc.) to corrode. However, please note that it is a myth that stainless steel doesn’t rust.

In the same way, galvanised steel is the most suitable material for a modular panel system and is the most efficient way to build a reliable and durable pool, but it can also be vulnerable to corrosion damage if not maintained properly.

We’ll now look into how to best protect these panels and the stainless steel pool accessories.

To prevent pool corrosion, you can take multiple steps, including regular maintenance of stainless steel materials, but also the use of sacrificial anodes, coatings, and sealants designed specifically for corrosion protection of the pool panels.

Pool maintenance

Ensuring that the pool is maintained adequately is an essential first step for corrosion protection. This involves testing the pool water regularly (manually or remotely) to check the chemical levels and keep the pH balanced to prevent electrolytic corrosion of stainless steel parts or the inox pool basin.

Keeping the pool water clean and clear will also help. Removing debris can play a part in preventing galvanic corrosion of stainless steel elements.

Stainless steel elements need to be cleaned regularly, at least twice a week. Special brushes need to be used when cleaning, so as not to scratch the steel. Also, cleaning should not be done with harsh chemicals such as bleach or ammonia. To remove rust stains and calcium buildup, use a special polish and a brightener in this order. First wipe off and remove accumulated dirt; then wash with a neutral soap solution with tap water and, finally, rinse with clean water and dry with a cloth. Surfaces that are frequently touched by hands, such as railings, should be cleaned daily.

Coatings and sealants

You can protect the pool basin of a swimming pool by coating them with specialised treatments. PVC liners and epoxy coatings and rubber-based sealants prevent corrosion effectively, thereby extending the life of pool panels and other steel materials.

Sacrificial anodes

These metal rods are built into the pool panels and protect their metal components from rust or corrosion. By being made of a less noble metal than the pool components, the anodes will corrode first, thereby protecting the components themselves. You should, of course, check the status of the sacrificial anodes regularly and replace them when they’ve become corroded.

Protecting your swimming pool panels from corrosion is imperative. It is also complex. You will need to consider the following factors:

• What metal the pool panels are made of;
• The environment in which the pool is located (humidity and other environmental factors play a role, too);
• The type of water used in the pool (its pH levels, what chemicals are used);
• How often is the pool used.

With this in mind, here are the most commonly used types of corrosion protection methods, with their characteristics.

PVC liner

The pool basin of a modular panel pool integrates a vinyl surface to the walls and floor of the swimming pool. Also known as a pool liner , this system is made of an extremely high-resistance polyester net, covered by two PVC sheets fused together. It is waterproof and very durable, protecting the pool from all external elements.

A positive factor of the PVC liner is that it also copes well with chemicals used to treat pool water. Moreover, it is an effective barrier against the proliferation of bacteria within the pool.

Epoxy coating

This is a type of paint that protects from water damage and from long-term exposure to chemicals. It’s one of the most popular methods of corrosion protection, as it can be applied to the surface of a panel relatively easily. It will thus create a barrier between the metal and the environment.

If you choose epoxy coating, you’ll need to consider what type of materials your panels are made of, and prepare them accordingly. This type of corrosion protection tends to last around 8 years (depending on how often the pool is used and the water and chemicals balance within it). Then, you will need to repaint the pool panels.

Galvanisation

By coating the pool panels with another, less noble, metal, you are creating a barrier and protecting the original pool panel. Zinc is often used for galvanisation and it creates a shield from the elements, reducing the risk of corrosion. Galvanising can last many years, so it is a durable solution against corrosion.

Anodic protection

This method involves connecting one metal to a more active one, the latter being the sacrificial anode. Adding this to your pool means that the more active metal will corrode first — and will eventually need to be replaced.

Cathodic protection

The opposite of anodic protection, this method adds a less active metal into the pool, which acts as a cathode. It prevents corrosion on the original pool panels by neutralising the corrosive agents in the water.

Once the pool basin is fully assembled, coated and filled with water, these mentioned corrosion solutions will especially protect the back side of the panels. This accessible area is also a very humid and chlorinated environment, so corrosion protection is also necessary.

To ensure a long life and less concern about the corrosion of your pool, there is the option of installing the pool with a Skypool system — offering a maximum corrosion resistance barely without maintenance. This is because these pool panels are made of hot galvanised steel, adding a film of zinc onto the panels from the beginning. The latter protects from corrosion and makes Skypool panels an excellent solution for pools with highly chlorinated environments.

As described above, by galvanising, we create sacrificial anodes for protecting the metal panels. This optimises installation costs from the beginning and reduces the need for ongoing maintenance. Skypool panels also last longer, which reduces costs in the long term and provides a pool that is protected from premature deterioration.