Protecting your assets from corrosion

Corrosion is a natural process that causes materials, usually metals, to deteriorate when they interact with water and oxygen. Salt speeds up corrosion, so coastal areas like Mackay and the Bowen Basin regions are particularly vulnerable.

Without undertaking prevention strategies, your business can be at risk of substantial losses due to damaged materials, equipment replacement costs, public liability claims, and lost business opportunities. While its occurrence can’t be entirely eliminated, the cost of corrosion can be reduced through corrosion protection services.

Unique industry and location influences result in corrosion taking many different forms. Because of this, preventive strategies can be highly complex, taking into account different environmental conditions, including soil resistivity, humidity, exposure to salt water and proximity to corrosion causing phenomena.

Abrasive blasting and protective coatings

Early detection, removal through blasting with various types of grit and the restoration of protective coatings are essential to stop active corrosion and prevent further deterioration.

Sandblasting and grit blasting involves the forceful application of a stream of abrasive particles onto a metal surface and can be used to clean, smoothen or roughen a surface before applying protective coatings.

Metallic abrasives include steel shot, steel grit, stainless steel shot, cut wire, copper shot, aluminium shot, and zinc shot. Non-metallic abrasives which are inexpensive, include silica sand, garnet, walnut shells, copper refinery slag, coal furnace slag, and iron furnace slag.

Abrasive materials used in dry blast cleaning are general dust hazards. Silica abrasives pose serious risk because they break up easily and produce large quantities of dust that could lead to Silicosis, a debilitating lung disease. Silica is not an option in certain parts of Australia where its use in dry blasting is prohibited.

Classes of surface preparation

Class 1 > Light blast cleaning removes loose mill scale, rust and foreign matter.

Class 2 > Medium blast cleaning removes substantial mill scale, rust and foreign matter from the surface, revealing grey metal.

Class 2.5 > Near white blast cleaning removes all visible residues such as oil, grease, dirt, mill scale, rust, corrosion products, oxides, paint or other foreign particles on at least 95% of the surface, leaving very light shadows, streaks or discolouration. This method is ideal for plant facility maintenance work.

Class 3 > White metal blast cleaning is the ultimate corrosion removal method which removes all mill scale, rust and foreign matter, revealing a uniform metallic white or grey colour. It promotes maximum performance of protective coatings, ideal for materials exposed to exceptionally severe conditions such as the constant immersion in water or liquid chemicals.

Outcomes of blasting with abrasive media will vary according to the type of abrasive, metal substrate, blasting method, abrasive velocity at impact, and the angle of the blast stream to the blasted surface.

Safety colour coding

You can reduce your OHS liability by safety colour coding your workplace. The Australian Standard 1318 requires the use of specific paint coating colours to mark physical hazards

and identify certain equipment in industry. Each paint coating colour has a standard name and contrast colour and is designated for specific areas.

The Safety Colour Code main safety colours are:

Red > Typically used to identify areas of danger, fire protection equipment, stop buttons or emergency stop controls. It is used with or without its contrasting white colour on rail crossings, stop signs, fire alarms and boxes, valve locations, sprinkler piping, areas around fire extinguishers, hoses, emergency stop switches or bars, and controls in hazardous machines.

Yellow > Contrasted with black, is used to identify areas where caution must be exercised radioactive hazards or sources are situated. Yellow is the colour of industrial locomotives, overhead fixtures that extend down into normal operating areas, low pulley blocks, crane hooks, low doorways, traveling conveyors, pillars or ports that may be struck, barricades, radioactive storage, and areas for collection of contaminated waste.

Green > Indicates areas of safety and first aid equipment. Its standard contrasting colour is white and it is used to mark the location of first aid facilities, stretchers, respiratory and revival equipment, showers, exit signs, and safety restriction signs.

Blue > Blue with white lettering is used for mandatory instructions which must be followed, signs depicting areas where personal protective equipment must be worn and general information.

Pipelines must be painted completely in standard identifying colours with or without bands of their supplementary colours for purposes of indicating their contents.

Cathodic protection

Metal that has been extracted from a primary ore tends to revert to its original state when affected by oxygen and water, with the result being seen as corrosion. It is caused by an electro-chemical process involving the passage of electric current between an anode and cathode in an electric circuit. In most industrial situations, environmental differences are the cause of corrosion (oxygen rich areas become the cathode, and oxygen depleted areas become the anode).

Cathodic protection (CP) prevents corrosion by introducing an element which is anodic to the metal being protected, and changing the base metal into the cathodic element of the circuit. Zinc is anodic to iron and steel and is often used in the CP of iron and steel materials. As the anode in the electric circuit, zinc will corrode, providing sacrificial protection to iron or steel.

CP is the ideal solution against corrosion for:

  • Pipelines
  • Ship hulls
  • Storage tank bases
  • Jetties and harbour structures
  • Steel sheet, tubular and foundation pilings
  • Offshore platforms, floating and sub-sea structures

The process of Cathodic protection involves 3 basic steps:

Surface preparation > This is the most crucial to ensure maximum corrosion protection;

Galvanizing > Which bonds the anodic metal and underlying steel or iron to create a tough barrier that withstands rough handling and keeps it free from corrosion;

Inspection > To prevent future corrosion damage.

In addition to corrosion protection, CP provides other important benefits such as:

  • Aesthetic appeal
  • Lower maintenance costs
  • Allows safety marking and colour coding
  • Ease of repainting.

Potable water protective coatings

Drinking water tanks and containers are vulnerable to deterioration and rely on tank linings and protective coatings for corrosion protection. For safety reasons, Australian Standards 4020 sets specific criteria for acceptable tank linings, which include standards for:

  • Odour
  • Taste
  • Appearance
  • Ability to support the growth of aquatic micro-organisms
  • Quantity of toxic metals and non-metallic substances which may be leached from the product

Various resins such as polyester, epoxy, and polyurethane can be used as protective coatings to line water tanks but the latest technology involves the use of Polyurea resin blend which is fast setting, highly elastic, impermeable and has good abrasion resistance. A resin reinforced with glass fibres provides optimum corrosion protection and lasts for years.

The selection of water tank lining involves careful consideration of important factors such as:

  • Quality of corrosion protection
  • Adhesion properties
  • Application under certain environmental conditions
  • Easy repair
  • Compliance with potability requirements of as 4020

As with any protective coating, water tank linings require careful application according to manufacturer’s instructions for number of coats, film thickness, recoat intervals, and curing conditions and times. We provide fiberglass reinforced tank linings and employ a team of qualified applicators who are skilled and trained in potable water protective coatings.

Tank lining coatings

Tanks are used to protect and store a wide variety of materials, including fossil fuels and potable water. You can ensure that they have a long lifespan by ensuring that they are built properly and by engaging experienced tank lining contractors to apply specialised protective coatings.

Tank linings provide corrosion protection and prevent product contamination. Time, elements, and daily operation can lead to gradual deterioration of the tank lining coating but inadequate surface preparation, incorrect choice, and application of paint coating are the main reasons for premature tank lining failure.

Choosing the right service to provide tank lining coatings is important — the best products and services result in longer lasting coatings, reduce the need for expensive maintenance and the risk of serious injury to personnel.

At Diamond Protective Coating Services, we ensure correct surface preparation, appropriate coating, and the right application technique to prevent tank lining failure. We know that other factors such as temperature and humidity must be monitored and controlled to ensure proper drying and adhesion. Applying tank lining coatings according to exact manufacturer specifications requires a level of expertise that our team implements daily.

Anti-graffiti treatment

Graffiti can be unsightly on any structure and often difficult and expensive to remove. Vandalism may be prohibited but it continues to be a problem that a growing number of our clients acknowledge requires a preventive approach.

Many anti-graffiti coatings are clear coatings which do not affect the appearance of the underlying structure. Generally, there are two types of anti-graffiti coatings – sacrificial and permanent coatings – that can be applied over existing paint or building facades.

Sacrificial coatings consist of polymeric materials which form a gel-like protective layer on the surface of a building or substrate. Spray paint used for graffiti will adhere to the sacrificial coating without penetrating the underlying surface. This type of anti-graffiti treatment works by forming weak bonds with the substrate making it easy to remove after graffiti is applied on the protective coating. A high-pressure washer can easily remove the invisible layer of sacrificial coating before a fresh layer is reapplied.

Permanent coatings create a protective surface which spray paint cannot adhere to. Graffiti appearing on the permanent coating can be removed using a simple solvent and some manual labour without causing damage to either the protective coating or the underlying surface. Permanent coatings that are correctly applied are long-lasting and require only a single application.

DPCS specialises in anti-graffiti material application and protective coatings that are water repellent, adhere well to underlying structures, UV resistant, easily cleaned, and environmentally friendly.

Commercial painting

Never underestimate the power of a tidy paint job! Diamond Protective Coating Services can provide a reputable painting contractor service for all your building and structure needs, with minimal work interruptions.

Wall colour can affect productivity, worker concentration and the amount of time spent in workstations. The right colour can brighten a room and require less lighting, or make a room appear cool and calm. The appropriate colour can add a professional look to your property, improving client, and investor perception, and attract more business in a cost-effective way.

Brighter workspaces and facilities are reported to experience fewer accidents, improved productivity and fewer absences, and for these reasons commercial painting services should be part of regular building maintenance.

Diamond Protective Coatings Services