Protecting metal with special metal coatings
Metal coating includes all coatings which are suitable for applications on metal surfaces. Metal as a material is very common in many industrial applications and construction. Industries such as aerospace, automotive and marine mainly rely on metal work. The popularity of metal is explained by its many positive properties; most metals are hard and shiny materials and they have electrically and thermally conductive properties. Different metal coatings strengthen or protect the properties of metal surfaces in order to guarantee the maximum life span of the material.
Protective metal coatings
Corrosion is the number one threat for metal structures and surfaces. Therefore, most of the metal coatings are corrosion resistant next to their other properties. Corrosion in general refers to erosion of metals. The most visible form of it is rust which can appear due to moisture, salt spray, oxidation or exposure to a variety of environmental or industrial chemicals. Besides corrosion prevention, coatings can also provide protection from chemicals. Other possible properties of metal coatings include:
- Abrasion resistance
- Fire retardance
- High temperature toleration
- Self cleaning and water and oil repelling properties (nanotechnology)
Consumer coatings for metal
The most consumer metal coatings are suitable for exterior and interior decoration. However, they also have protective characteristics due to metal being sensitive for corrosion. Additionally some functional coatings are on the consumer market even though they may require more safety measures and professional application tools. Such coatings include for example vehicle refinishes and yacht and boat paints.
Preparing for application
In every coating application, the metal surface must be appropriately prepared in order to allow the best adhesion and equal paint layer. First of all, the substrate should be completely free from rust and grease. Once the surface is clean, a metal primer is usually recommended due to the fact that it provides extra protection and better adhesion. The top coat application can take place once the primer is completely dry. Note also that some primers require sanding before a finish.
Most liquid coatings can be applied with a roller or brush. Nevertheless, spray applications are also possible. Sometimes they may require professional equipment but most of the times they come in an aerosol can and are very easy to apply.
Industrial metal coating applications
Industrial coatings are those applied on objects/surfaces during manufacture. Both, liquid metal paints and powder coatings are suitable for industrial applications. Today powder coatings are more popular than the liquid alternatives due to 0% VOC content and extreme toughness.
Besides roller and brush applications, there are many other methods for the industrial coatings including:
- Low pressure spray
- Airless spray (also available for 2K systems)
- Electrostatic spray (often for powder coating)
- Robot operated spraying techniques
- Curtain coating
- Dip coating
Metal coating suppliers in Australia
Level 13, 135 King St., Sydney 2000, Australia
612 8973 7499
Astor Metal Finishes
93 Malta Street
Fairfield East 2165
+61 2 9727 5622
a division of George Lovitt (Manufacturing) Pty Ltd
202 Holt Parade
Thomastown VIC 3074
Telephone +61 3 9464 0922
Fax +61 3 9464 0548
Conversion coating decorates and protects metal. This type of coating is a layer which forms through a chemical reaction between a chemical solution and the metal. The metal surface is, thus, converted into the coating. The process is usually a dip application where the metal is dipped into a chemical solution. This, thus, allows conversion of the metal surfaces. Conversion coating is good for several purposes including:
- Protecting metal from corrosion
- Retaining conductivity
- Increasing substrate durability
- Pre-treating (priming) metal surfaces
- Decorative purposes
Types of conversion coating
The most common forms of conversion coatings are chromating and phosphating. Chromating passivates steel, aluminum, zinc, cadmium, copper, silver, magnesium, and tin alloys. It is ideal for corrosion prevention. However, it has also decorative properties. It is, thus, suitable for metal decoration. It, additionally, is suitable for conductivity retention and metal priming. Phosphate coatings for their part, are crystalline conversion coatings which are formed on ferrous metal substrates. Phosphating is a way of metal priming. It protects the surface from corrosion and improves friction properties of sliding components. Applications of ather paints and coatings usually take place on phosphate surfaces. There are also more sustainable phosphate free and heavy metal free formulations of conversion coatings. Not only do they coat but also clean metal surfaces.
Conversion coatings for pre-treating metal
- Iron Phosphate Conversion Coatings: chemical coatings which make the metal nonmetallic. They are iron phosphate coatings which prevent and improve the adhesion and durability of paint finishes.
- Light Metal Conversion Coatings: ideal for creating a spectacular paint base for aluminium substrates. Also eco-friendly variations of these coatings are available.
- Manganese Phosphate Conversion Coatings: anti corrosive coatings which make pistons, rings, liners and other bearing surfaces more durable by preventing metal to metal contact.
- Nanoceramic Conversion Coatings: an alternative to traditional iron phosphate using nano technology.
- Phosphate Free Conversion Coatings: eco-friendly, new-age chemical coatings which have low energy, maintenance and treatment requirements. These coatings can also lead to significant savings in industrial processes.
- Zinc Phosphate Conversion Coating: coating which turns metal substrates into nonmetallic surfaces which consist of iron, manganese, nickel and zinc phosphates.
Conversion coating Australia
Conversion coating process is purely industrial. Therefore, it must take place in a professional environment. In Australia there are several companies which provide conversion coating services. For example Electromold Australia is an expert in chemical coatings including conversion coatings. Henkel is one of the leading manufacturers and offers thus most products to the industry.
Special metal coating for aerospace
Aerospace coating, or sometimes referred as aircraft paint, aircraft coating or aviation coating, include coatings for commercial and business aviation as well as for military air market, satellites and launch vehicles. Therefore, airplanes, helicopters, jets and other aircrafts flying above Toronto, Vancouver, Edmonton, Calgary and all over Canada are also aerospace coated. The aerospace coatings market covers OEM (original equipment manufacturers) and MRO (maintenance, repair and operations) branches.
Protect airplanes with aerospace coating
Many different types of coatings are applied on airplanes due to the fact that they are complex compositions which must endure extreme operating environments.
An airplane is coated from the inside and the outside. The interior coatings must be resistant to corrosion for a long time due to limited access. An interior coating is often good for 20 years. The exterior, for its part, must be repainted more often.
Like most of the coatings, aerospace exterior coatings also have decorative and protective purposes. For example airline companies often express their logos and slogans on the airplanes. For instance, Air Canada’s red, white and silver . Additionally, the coatings can positively affect the performance. The following are some advantages of aviation paint:
- Protect from climate extremes and contamination
- Prevent corrosion, fading and aging of the paint
- Resisting dirt and other contamination
- Improve laminar flow and reduce drag leading to lower fuel consumption
- Protect the surface from chemicals such as anti-ice and hydraulic fluids
Aerospace coatings and paint technology
Aircraft paint and coatings are constantly further developed to increase the quality and improve the properties. The aerospace coatings market is concerned with economic and environmental sustainability. Therefore, aerospace coatings and paint technology is constantly improving. Nano coatings for dirt resistance and drag resistant coatings are constantly developed and tested. It is also important that the coatings retain shiny colours for long time.