Powder coatings are generally a one coat finish, applied to suitably cleaned and pre-treated substrates. Some coatings such as metallics may require a clear coat to protect the metallic effect, although these are generally being replaced with the DGL Electro™ Powder Coat Ranges which do not require a clear coat.
Powder coatings are a factory applied finish using specialised equipment. The equipment includes an electrostatic spray gun, spray booth and an oven to bake (or cure) the coating. On site application is not possible given the hot curing cycle required to fuse the coating.
Whilst powder coatings generally require no primers, it is important to provide a clean and pre-treated surface for the powder coat to adhere to. Metals that are planned for internal locations can escape the need for pre-treatment.
Unfortunately there is a myth that since powder coating is easier to apply than wet paints and retains a very hard finish, that powder coatings can withstand anything and everything. Indeed this carefree view has led to some disappointing applications of powder coatings. Powder coatings rely on a clean, pre-treated surface like any and every other coating.
Rusty metal deposits must be removed prior to powder coating, as over coating with powder will only mask what is fundamentally corroding metal. Powder coatings provide very good resistance to knocks and abrasions, chemicals and the effects of sun. However, if not cared for, the coating can show up scratches and film integrity loss.
Some powder coatings can be designed specifically for contact with food but this is a specialised application that could be developed on a Made To Order basis. If this feature is required, you should contact DGL International for further information as the standard ranges of powder coatings are not suitable for contact with food.
Some powder coatings can be specifically designed for electrical properties, but again, as with food grade coatings, this is specialised and you should contact DGL International for further advice.
Whilst powder coatings have the advantage over solvent based coatings of having a lower explosion point and therefore less flammable, caution should always be exercised with any electrical source such as mobile phones. Powder coatings are a fine organic dust which in high concentration, in the presence of air and an ignition source such as a mobile phone, could trigger a dust explosion.
The concentration of dust required to facilitate a dust explosion is significant, however, it is advisable to keep unnecessary equipment away from the booth and powder. As a precaution, DGL recommends that mobile phones should be kept clear of these areas.
Powder coatings are produced by dry blending resins, pigments, additives and curing agents which are then extruded at elevated temperatures to melt and mix the ingredients. The material then becomes thick and viscous like a honey mixture which is cooled using super chilled water, before the material is crushed progressively to a fine, well defined particle size. Specialised equipment including rotary sieves and particle size measuring equipment is used to monitor and control the particle size distribution.
DGL International produces powder coating products for markets including (but not limited to) South East Asia, Australia and New Zealand from factories in Australia, New Zealand and China.
Not all colours behave the same during application or performance on site. Generally, light colours are ideal for more applications than other colour groups.
Light colours absorb little light because the white pigments help reflect the light. This reduces the heat up effect on parts. Dark colours absorb light and hence heat far more readily, which explains why dark cars are hotter than white cars in the sun. If heat is an important element in the design or use of your product, the effects of light and dark colours are an important consideration.
Bright colours behave differently again as they not only absorb light and remit this as brightness, the pigments are more readily damaged by ultra violet light reducing the life of the colour. Bright colours that include reds, oranges, greens and blues are recommended for applications where colour retention is not critical such as playground equipment and furniture.
If you cannot find the colour you require for your powder coating, you can enquire about a custom colour that will be made to order. We recommend you speak to a DGL Account Manager or send an enquiry here. To send an enquiry to our Advice Line, please visit the Contact Us page.
Paints and powder coatings have evolved from different industries; house paints from decorative applications and powder coatings from industrial uses. While DGL has endeavoured to align colour names across industries, there are examples of colours e.g. Magnolia, which exist in both paints and powder coatings.
It is recommended when choosing a colour that a colour sample of each product be reviewed to ensure the colours chosen meet your needs.
DGL can produce special colours and finishes on a Made to Order basis. Due to the nature of the manufacturing process, minimum quantity conditions limit the possibility of non-standard colours to typically large or ongoing projects. It is recommended when choosing colour, the powder coating colour be chosen first, as almost every powder coat finish can then be matched in a DGL paint system.
There are various standards for powder application, covering the correct procedure for pre-treatment, powder application, testing and performance. The standards generally relate to the nature of the substrate. Please refer to our How to Specify page for further information.
Australian Standard AS3754 – Safe application by electrostatic spray outlines the procedures for safe application of powder coatings. Copies of this standard can be obtained from your local Standards Australia office.
The Safe Work Australia Spray Painting and Powder Coating Code of Practice provides practical guidance for powder coating businesses and can be found here
DGL recommends reference to the Australian Standard AS3754 – Safe application by electrostatic spray for correct handling of powder coatings. In general use of a dust mask, protective clothing and/or barrier creams are recommended.
There are various standards for powder coating depending on if the aspect of the standard focuses on safe application, metal finishing and end use application e.g. coatings for children’s toys or quality test standards. The standards generally relate to the nature of the substrate.
Please refer to the following standards for further infomtation: AS3715, AAMA 2603, AAMA 2604, AAMA 2605 & Qualicoat class 1, 1.5, 2 and 3
For aluminium substrates, Australian Standard AS3715 – Metal Finishing – Thermoset Powder Coating for architectural applications is recommended and most commonly referred to in Australia.
For general metals including steel and galvanising, the Australian Standard AS4506 for Metal Finishing – Thermoset powder coatings is recommended.
The most recognised standard of durability of coatings is the AAMA standards. The AAMA standards are based on performance criteria set out by the Architectural Aluminium Manufacture’s Association, from where the reference to AAMA originates. The three AAMA standards used to specify powder coatings are below;
See How to Specify page to find out more information regarding specifying the correct AAMA Standard.
There are many standards established simply to outline an agreed standard for measuring a coating’s performance. Examples of common tests might be gloss measurement, adhesion of coatings, weathering performance, hardness, chemical resistance or stain resistance. Among the many standards are the Australian Standard AS1580 – Paints and related materials – Methods of Test, AS3715 and AAMA 2603, 2604 & 2605
Copies of standards can be purchased from your local Standards Australia office in major capital cities or by accessing one SAI Global here.
Powder coating storage stability varies according to the technology and the storage conditions. Generally DGL recommend 2 years before the powder is re-tested to confirm no degradation in film properties. If the powder has become lumpy and absorbed moisture, the material may be sieved and then fluidised for 10 minutes to condition the powder in preparation for application.
Powder coatings are generally all not classified as Dangerous Good as there are no solvents in powder coatings which simplifies the transport and storage of powder coatings.
Zincshield is an exception which is classified as a Dangerous Good by the criteria of the “Australian Code for the Transport of Dangerous Goods by Road & Rail”
DGL International Powder Coatings have a comprehensive product stewardship programme to ensure that all products are monitored for chemicals of concern in line with leading international directives. This includes compliance to RoHS3 (EU2015/863). You can download a copy of the Restriced Hazardous Substance statement here.
DGL Powder Coatings:
Consequently, DGL Powder Coatings are a prime consideration for projects where air quality standards have been set, such as 4, 5 & 6 Green Star Rating Projects.
Please refer to the product Safety Data Sheets for more information on appropriate equipment for clean up.
Powder coatings can be safely cleaned up via a brush and spade or a vacuum cleaner, provided the amount of powder is not excessive. For large spills, the powder should be shovelled into a plastic bag inside a carton and tipped into the box for easy disposal.
The rules and regulations for powder waste disposal vary across states and regional councils. In many instances, powder coating is suitable for land fill; however it is important to contact your local council and/or Environmental Protection Agency office to clarify local requirements for waste disposal.
As a rule, ensuring waste powder is placed in securely sealed packs with no leaks is important to limit nuisance dust. This will ensure that powder is not emitted to the atmosphere when loaded to the waste truck on your premises and hence avoid subsequent complaints from neighbours.
Please refer to the product Safety Data Sheet for more information.
The effects of pollution, dirt, grime and salt deposits can all accumulate on a powder coated surface over time. To extend the effective life of powder coatings and fulfil any warranty requirements that may exist, a simple regular maintenance program should be implemented for the removal of residues. As a general rule, all powder coated surfaces should be cleaned every twelve months.
However in areas where pollutants are more prevalent, especially in coastal or industrial regions, a cleaning program should be carried out on a more frequent basis. To clean a powder coated surface, customers should carefully remove any loose deposits with a wet sponge and then use a soft non-abrasive brush or cloth in combination with a mild household detergent solution to remove dust, salt and other residues. Finally rinse all powder coated surfaces with clean water.
See our Care & Maintenance page for further information.
Powder coatings are considered extremely resilient and have been a coating of choice for use on gas and oil pipelines which are buried in earth or underwater. Powder coatings have also been used on automotive and appliances given their excellent chip resistance, hardness and chemical resistance.
Please refer to the Alumi Shield warranty pages for further information.