The right kind of tank lining coating saves you time and money
Protection-wise, tanks present a series of issues. Not only does their exterior (tank coating) need to be protected from the environment, but their interior (tank lining) needs protection too – both from and for the cargo or substance being stored. These substances can be anything from petrochemical to water to beer, and the coating needs to combat the specific adverse conditions that accompany the substance without contaminating it. To achieve this, tank lining and tank coating are formulated to be chemically resistant, hygienic, resistant to high temperatures, and capable of application over previously damaged substrates.
Starting off with the right coating will save you expensive problems down the line, and re-coating a tank is only 10% of the cost of replacing a tank. Whether you need tank coating for a new project, or need to recoat one that is no longer functioning optimally, there is a coating to match your need. In this article we will outline the many benefits of industrial tank coatings, tank linings and how to choose the right one for your project.
7 questions to find the right tank coatings and linings
The requirements for an external tank coating are compatibility with the substrate as well as providing it with appropriate protection in the specified environment. Therefore, the two questions to ask yourself are:
- What is the external surface of the tank made of? Concrete, steel (mild, galvanised etc.) and fibreglass all need tank coatings especially made for the substrate.
- What are the environmental hazards the tank may be exposed to? temperature fluctuation, corrosion, salt spray etc.
A tank lining needs to match both the substrate and the storage. They form a barrier, protecting the internal substrate from corrosion, chemicals, and heat, and protecting the contents from contamination. The difference between tank lining and tank liners is that where tank lining is bonded to the substrate, tank liners are freestanding within the tank. In order to determine the suitable tank lining for your project, you need to be able to answer these 5 questions:
- Which substance does the tank store? Chemicals, foodstuffs, water, each store has different needs.
- For how long will it be stored? Coatings can be formulated and applied to provide longer protection against constant exposure.
- How high (or low) will the storage temperature be? Both the environment and the cargo need to be taken into account.
- What is the maximum allowed downtime during the application? Different coatings have different application and curing times.
- What are the local regulations regarding tank linings for your type of tank? The lining needs to comply with local standards.
What you need to know for tank protection
The purpose of your tank will be the shaping influence on which coating you choose. This is particularly important for:
- WATER TANK LINING – Tanks for both potable water and other kinds of water (waste, raw, etc.) make up most tank usage in Canada. For potable water it is of vital importance that the internal tank coating or the lining do not contaminate the water, just as it is important that the coating protects the tanks from corrosion. In Canada there are regulations for the coatings used for potable water. For wastewater tanks, the coating needs to be highly chemical resistant, as well as preventing the pollution from within the tank seeping into the environment, especially where the tanks are underground.
- CARGO TANK LINING – For cargo tanks, the storage changes with each new job. Because of this, the lining chosen needs to protect your tank against harmful or corrosive cargoes while also reducing maintenance and ensuring a long service life. A tank lining coating should reduce turnaround times between cargoes, allowing a quick switch and eliminating contamination between cargoes. It is important for cargo tanks to have chemical resistance, so common cargoes such as petroleum or oil do not damage it.
The 3 most common types of tank lining
In Canada a major part of all tanks is used either for storing or transporting a spectrum of substances. Mild steel tanks are the most common but also other materials such as fibreglass and concrete are becoming more and more popular. So, let’s look at the different tanks and the tank linings they require. The incorrect choice of tank lining may lead to softening, contamination or even failure of the coating, likely to have severe consequences.
1. Epoxy tank linings
Epoxy is a versatile coating type with many applications. Epoxy tank lining can be solvent-free to reduce VOC emissions, and protects against corrosion in aggressive and high temperature environments.
Uses: Water tank linings (potable and other), steel tank linings, concrete tank linings, chemical tank linings, high temperature tank linings, cargo tank linings where protection against chemicals, oils, waste water, high temperature crude oil is needed.
Disadvantages: Not a very flexible coating, slow curing, impermeable so water vapour may cause blistering.
2. Polyurea tank linings
Polyurea is a hot spray applied coating which dries in seconds to minutes, with the shortest cure time of all the options. It has great strength and flexibility, and the highest tensile strength of the coatings – allowing for stretching with a substrate under temperature extremes. Polyurea is solvent free (no VOC), moisture insensitive (unlike the other two), has a long service life, and is also abrasion resistant.
Uses: Water tank linings (not potable, but excellent for wastewater), steel tank linings, concrete tank linings, chemical tank linings
Disadvantages: Not vapour permeable, not always suitable for food storage – look for proof of approval for direct food contact.
3. Polyurethane tank linings
Polyurethanes are, like epoxies, a very versatile coating, and they have the benefit of being able to be modulated so they are more or less flexible/brittle. They can also be solvent-free, and have faster return-to-service times than epoxy.
Uses: Water tank linings, steel tank linings, concrete tank linings, chemical tank linings
Disadvantages: Not vapour permeable (possible blistering), and very moisture sensitive when applied.
Tank coating and lining products and specialists in Canada
For quality assurance and expert application, we advise you to have your tank coating and linings applied by trained, experienced professionals. The risk of a coating failure due to poor or wrong application is too costly a gamble. We have compiled a sample of the products used by applicators in Canada, to give an idea of the products available.
Offers the following product lines:
- Ceilcote for concrete and steel structures
- Devoe chemical resistant lining system for multiple substrates
- Polibrid for steel and concrete ( excellent for water and wastewater applications)
- Interline corrosion protection and reducing cross cargo contamination.
Offers the following product lines:
- Amercoat for steel and concrete (also available for low temperature applications)
- Novaguard for resistance to a wide range of chemicals, solvents and refined fuels and even biofuels.
- Sigmaguard for resistance to crude oil up to 140ºF (60ºC), aliphatic petroleum storage with pit filling properties
Offers the following product lines:
- Tankguard Plus chemical resistance at high temperatures
- TG Storage made for long term storage of chemicals
- SF is solvent free. Film thickness as low as 150µm and up to 500µm
- Chemflake is a glass flake reinforced unsaturated vinyl ester coating, fast curing
Fortunately, considering the importance of a professional tank coating, Canada has many companies which specialise in applying tank lining coatings and external tank coatings. If you would like more information about tank lining, or have a tank lining project that requires coating expertise, get in touch! Our experts are here to help, and ready to connect you with one of our coating partners to best complete your project. Just click the “Request a quote” button at the bottom of this article and take advantage of our 100% free quote service.