What is it? Powdercoating is an organic finishing process where specially formulated polyester, epoxy powders, or more specialised powders are applied over the product surface by the use of electrostatic guns. The product is then placed in an oven where the powders fuse and react together forming one of the most durable of organic coatings.

What materials can be Powdercoated? Almost any metal can be Powdercoated that can withstand the 200˚C oven temperatures required for curing the powder. Products that are soft soldered, lead alloys and other low melting metals are unsatisfactory. Products previously chrome plated or finished by other means may not Powdercoat well. Plastics and other nonconductive materials are difficult to Powdercoat as they do not conduct the electrical charge without special surface treatment.

How is it done? The commercial Powdercoating process has four basic steps. Firstly the surface is cleaned. Then chemical conversion coatings are applied to assure good adhesion. The metal surface is chemically treated to obtain a finish that bonds the coating to the metal. These treatments are normally of the iron or zinc phosphate type for steel or iron alloys and chromium conversion coatings for aluminium alloys. Although you may appear to have good adhesion without pretreatment the life of the product will be greatly reduced. Aluminium surfaces are prone to interface corrosion where the bond between the metal and the Powdercoat fails after a period of outdoor exposure without correct pretreatment.

Then the Powdercoating is applied. The process of Powdercoating consists of a special type of spray gun where the powder is atomized and charged with a high voltage (100,000 volts). The highly charged powder is attracted to the earthed product being coated. Baking then follows. The baking process fuses the small powder particles together to form a continuous coating and then a hardener in the coating reacts with the resin and cures the film.

Where should Powdercoatings be used? Powdercoatings have made major inroads into the wet painting industry over the last 10 years generally giving superior performance in nearly all service conditions. Added benefits of powder are the range of surface textures that can be achieved by powder that will assist in covering surface defects. The thickness of powder (average 50 microns) gives wear resistance better than most wet finishes. As there are a number of powder formulations that can be used, your end requirements must be clearly defined so the best product can be selected.

How colourfast are the coatings? Most Powdercoatings are designed for average exterior use. Generally you could expect to loose some of the surface gloss after some years exposure although the basic colour should remain. Special powders are available for architectural use that will give increased performance.

What thickness is Powdercoating? Powdercoating is one of the thicker metal finishes and allowances must be made for this buildup. Coatings can range from 20 microns to over 100 microns, on some complicated shapes to get coverage in recesses the coatings on the edge may exceed 150 microns (or 1.5 mm).

What is chemical pretreatment? To obtain satisfactory adhesion to any metal the surface needs to be pretreated. Remember that all Powdercoating suppliers are not the same and unlike some Powdercoaters, Finished Product strictly monitors all aspects of our production line to make sure that the work we do will consistently meet all your quality requirements.

How flexible are Powdercoatings? Standard Powdercoating has a degree of flexibility. Special powders are available that have increased flexibility where it is possible to post form sheet metal components. It should be noted that powder adhesion and flexibility are related; poor pretreatment will not allow any degree of post forming.

Can the powder be masked from certain areas? High temperature masking tapes, silicone plugs and sleeves can be used to protect areas from Powdercoating. These processes are labour intensive and can be quite expensive. Masking tape can be very difficult to remove after Powdercoating as the powder tends to bridge the tape and may require the powder to be cut to remove the tape.

What are the design considerations for trouble-free Powdercoating? Don't design products that will trap chemicals during the pretreatment process. Tubular products should have drain holes suitably positioned. Consideration should be given to powder buildup. Scale and rust may reduce your metal costs but these will present Powdercoating problems in either poor adhesion or resultant surface imperfections. Don't use marking pens or other inks/paints on your products that will not come off in the cleaning process. Specify the end use of the product so we can process the product accordingly. Point out the critical areas of the product and allow for a hanging point.

Can I Powdercoat over anodic coatings? Anodising is not the best surface for painting or Powdercoating over as the insulating properties of the anodising will cause problems will the earthing of the product for good electrostatic attraction. The anodic film also prevents the chemical conversion coatings from reacting with the aluminium resulting in poor adhesion. It is best to strip off any anodic films before Powdercoating.

Can Powdercoating be used in contact with food? Standard Powdercoatings are not FDA approved for contact with food. It is recommended that you contact the Powdercoating manufacturers for specific recommendations.

What does it cost? Powdercoating is one of the cheaper metal finishes. Type of pretreatment, shape, and size of product all have a bearing on costs. Additional charges are made for labor in the racking and packing of small components; please feel free to contact us for a quote.

What is the maximum size Finished Products can process? Finished products has a fully automated line that can process work of a maximum length of 3 metres, height of 1.6m and a width of 0.9m.

For more information on Powdercoating or to find out how Finished Products can help you achieve outstanding results for your surface finishing requirements, please feel free to contact us by telephone on +612 9602 9833 or send us an email by clicking on the "Contact Us" link below.