Home Rainwater Harvesting Rainwater Products Blue Mountain Mesh™ Stockists Contact Us
Metal/steel tanks
 
A popular choice

Metal/Steel tanks have been popular for years and continued development of new colours, shapes and sizes has ensured they still are. Some years ago they were made from rolled sheets of galvanised iron and riveted and soldered to prevent leaking. They were the backbone of water storage the world over. Now the plain metal tanks are typically made from ZINCALUME®, and the coloured tanks are made from a special type of COLORBOND® steel - AQUAPLATE®.

Traditional 'galvanised' tanks

There are some very important factors to understand when it comes to metal/steel tanks. In the past the humble tin tank has been described as a "galvanised tank". Galvanising is the process of applying metal to metal and the "galvanised tank" is made from zinc galvanised to steel. These "galvanised" tanks could be soldered. Solder consists of a combination of lead & tin which is melted with a hot iron and applied to a joint was prepared with spirits of salts. These metals were similar to each other, deemed compatible and adhered to each other under heat.

ZINCALUME®

Then along came ZINCALUME®, a high tensile roofing product that revolutionised the roofing industry, it was strong, came in long one-piece sheets that reached from the roof ridge to the gutter without a join.
The emergence of ZINCALUME® (primarily a zinc and aluminium mix of metals "galvanised" to steel) as a popular roofing material brought problems for the trusty galvanised water tank. In the early days there were instances where new ZINCALUME® roofs were installed and within months the galvanised water tank had rusted out. The tank would break out in brown freckles and in a short time the freckles would begin to join up and the tank would collapse and the owners would then realise that the freckles were rust. The freckles/rust were caused by electrolysis. Electrolysis is a result of metals of opposing make up being joined together, in this case with water, which then creates an electrical field like a battery. The electrolytic action corrodes away the less noble of the two metals and in this case the galvanised tank.
Nowadays electrolysis is still possible where a building still has a galvanised (zinc) roof which supplies water to a ZINCALUME® tanks.

AQUAPLATE® - a new era
 
AQUAPLATE® is a top of the range metal tank material that is made with a special internal liner and is warranted for 20 years
 
 

COLORBOND® steel tanks that are popular today are actually made from a material trademarked AQUAPLATE® by BlueScope Steel Ltd. The AQUAPLATE® tank is a top of the range metal tank and is lined with a special liner material that is warranted for 20 years. These polyethylene linings prevent corrosion and ensure water quality. It is important to note however that the polymer coating is not resistant to prolonged exposure to sunlight, and the warranty covers the material only and not the construction. The construction method used for AQUAPLATE® tanks is such that joints can not be soldered so adhesive sealants are used on the inside of the tank to cover the seams, some tank makers also sandwich the sealant between the overlaps of the sheets.

Metal tanks are also available using a modular construction system which ensures strength, water quality and makes delivery onsite more manageable. These modular tanks can be built to store significant water volumes and are extremely popular in rural and commercial applications.
Suitability

Extremely strong tanks with polyethylene tank linings to prevent corrosion and ensure water quality.
Site Preparation : A concrete base is required or an approved tank stand
In Ground : No
Guarantee : Ask your supplier for a written guarantee for both the material & the workmanship.
Repairable : Yes, seams can be resealed by the manufacturer.

COLORBOND®, ZINCALUME® and AQUAPLATE® are registered trademarks of BlueScope Steel Limited
 
Safer than mains water?
Rainwater Research
Ideal uses for rainwater
Reasons for using rainwater
How to Create a Complete System
Water storage and tank selection
Types of water storage vessels
Above or below ground
Concrete tanks
Metal/steel tanks
Poly/Plastic tanks
Fibreglass tanks
Bladders
Choosing the size of your tank
'Wet' and 'Dry' systems
Pump selection
Recommended systems
Regulation and Rebates
top of page