Galvanised versus Zincalume

The debate continues Galvanised steel versus Zincalume

You may keep coming up against this question is Galvanised better for water tanks or is Zincalume?

Well the answer is it depends (how surprising)!!

In reality both materials have there pros and cons in the water tank environment firstly it all depends if the tank is being constructed with the latest technology Bluescope Next Generation Zincalume and the thickness of the galvanised coating. It also greatly depends on the engineering of the tank to mitigate any risks or concerns on either material. There is no bases behind the generic statement being made by some that galvanised steel out performs Zincalume for corrosion resistance.

All Pioneer Water Tanks are manufactured using the latest generation ZINCALUME. According to Bluescope ZINCALUME® with ActivateTM technology offers far greater resistance to atmospheric corrosion in ALL normal roofing and walling conditions. ( it typically lasts 4 to 6 times longer than Galvanised G275mm). Read the full Bluescope Corrosion performance document attached below this article.

According to Bluescope Corrosion protection on steel traditionally follows 2 paths one being Barrier and the other Sacrificial protection.

Barrier protection

Barrier protection is when steel is coated with a material that prevents moisture and oxygen making contact with the base metal as in the absence of moisture and oxygen steel does not corrode. In a metal coated context, coatings consist of inherently corrosion resistant metals such as Aluminium, Tin, Gold, and so forth the advantages of this protection is that these coatings are long-lasting and resistant to temperature change, abrasion, erosion, UV and are often electrically conductive. On the down side if the coating is scratched or cracked localized corrosion will occur.

Sacrificial Coatings

Works off the principle that all metals have the potential to corrode, this potential is referred to as “activity”. When steel is coated with a more active metal, the active metal will corrode in preference to the steel and provide protection from the corrosive influence, in other words the active material will sacrifice itself. Sacrificial coatings are effective even if the steel substrate is exposed, as it is based on electrical conductivity. Sacrificial coatings physically migrate to a corrosion site to provide protection. Galvanised steel relies mainly on sacrificial protection to resist corrosion. Galvanised steel is coated in almost pure zinc.

Duplex Coatings (combination of Barrier and Sacrificial Coatings)

Alloying of metals with differing corrosion performance allows coating to be created that offer both barrier protection to protect the underlying steel, but also sacrificial protection in the event the steel is cut, scratched, drilled or damaged. These coatings are very long lasting and at the same time protect exposed areas of steel.

ZINCALUME® steel employs a combination of both barrier and sacrificial protection

ZINCALUME® steel is coated in an alloy of approximately 55% aluminium, 43.5% zinc and 1.5% silicon. Although both Galv and Zincaclume are produced as continuously hot dip coated products, they perform very differently, especially in construction industry applications such as roofing and walling. All coatings protect steel sheets from corrosive attack by acting as a barrier
to exclude air, water and other corrosion causes from contact with the steel substrate.

Pioneer Water Tanks have been manufacturing water tanks for over 30 years originally using Galvanised wall panels and moving to Zincalume due to their belief that this is a better performing steel in the water tank environment.

Some real engineering features that further mitigate the risk of corrosion!!

All Pioneer Tanks are manufactured with a bottom lip on the 1st panels to prevent them ‘digging’ into the ground this also server the purpose of ensuring the tanks can accommodate moderate ground movement and do not become entrenched in wet moist soil. Pioneer Tanks are all fitted with Condensation strips which ensure condensation from the roof area runs into the tank and not behind the liners. Pioneer use the industry leading Aqualiner to minimise build up of moisture between the tank walls. As an extra layer of protection Pioneer is committed to supplying all tanks with Sacrificial anodes. There is in fact no science behind the statement that Tanks made using Galvanised material are any more or less protected than Zincalume Tanks and therefore do not require this additional protection. In fact the experts say sacrificial anodes would have the same affect on both materials.

Rest assured when buying your new tank from Pioneer Water Tanks you are getting only the best, that’s why we at Divine Water Tanks agree You’ve Made the Right Choice.

No Need to take our word for it please find these interesting articles below from independent sources.

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