In our continuing efforts to improve quality and service, and ensure ongoing satisfaction, our Quality Assurance Team provides these guidelines for customers. They cover our requirements for delivery of products and component parts to Powder Coating Services for finishing, and also offer some advice on caring for powder coated products once in use.
Some issues raised in the following are unavoidable in certain circumstances. But with due preparation and on-going product care, your powder coated items can be expected to serve their purpose and stay looking good for many years.
Labelling
All parts to be powder coated should arrive at Powder Coating Services Ltd clearly labelled, with your name and if practical the powder coating colour required written on each separate piece. For business customers, your purchase order should be included on delivery, with a detailed description of parts to be processed - i.e. quantity, size, colour, part numbers if applicable, and any special packaging instructions. This will insure that your material is easily identified and efficiently processed.
Packaging
Please ensure that packaging, containers, pallets etc. used in delivery provide proper protection against damage. For example, palleted material should not be larger than the pallet itself or overhang its sides. Items will be repackaged in the containers you provide, so packing must provide suitable protection against damage after, as well as before, powder coating.
Markers
All materials to be powder coated should be free of inks, such as those from markers or other writing materials. These inks can show through the finished coating, particularly when the product is finished in lighter colours.
Weld Spatter
All welds should be clean, and the surrounding area free of weld spatter wherever possible. The heat involved in the powder coating process can not only change material properties, but also incorporate contaminants into the part surface. Our pre-treatment process is designed to remove surface contaminants, and is not a suitable substitute for mechanical cleaning. Unclean welds invariably compromise the integrity of the powder coat, resulting in bare spots and pinholes in extreme cases.
Packaging Debris
All parts to be coated should be free of packaging material and shipping debris. While our inwards goods procedures include inspection, experience has alerted us to certain recurring issues. These include clear tape adhering to items, which can be almost impossible to detect, especially in large orders. The end result of melted tape on the item is generally coating failure due to total loss of powder adhesion. We strive to minimise this problem by working with our customers, and ask you to be mindful of the issue in all cases.
Oxidation and Hot-Rolled Steel
Any type of oxidation (rust, white rust, etc.) will negatively affect the final product quality. Our pre-treatment processes remove light to medium oxides or scale. However if a material is severely corroded, or has even been lying in an unclean state for an extended period, it will have reduced corrosion resistance and the prospect of a lower quality finish. Seriously corroded material should be mechanical re-finished before delivery to Powder Coating Services.
Galvanised and Zinc Materials
Poor quality galvanised and zinc coatings will adversely affect the final powder coated product. Powder Coating Services Ltd is not liable for lesser finish quality on any material that does not meet accepted standards of pre-coating. Our customers are responsible for the condition of their items before they arrive at our site.
Drainage
All items fabricated from tubing should have drain holes, as powder will not adhere to a tube with water trapped inside. Also pertaining to holes, in the powder coating process all parts are hung on a line, and how this is done must be considered. This issue is addressed on placing orders, when we will advise of any special requirements.
Clear Powder Coating over Mild Steel
As a highly reputable operator of a major powder coating plant supplying mainly to the Wellington region, we have considerable experience in powder coating both matt and gloss clear finishes over mild steel for interior displays, shop fittings and furniture. We advise clients specifying a clear powder coated finish to consider the issue of durability, even in an interior environment. Please note the following.
There is potential for mild steel with a clear powder coating to corrode. A clear powder coated finish is not considered a fully approved industry practice, any more than a single clear wet spray is. That is the case regardless of whether the product will be used in an interior or exterior environment.
To achieve a level of durability acceptable for exterior use, clear powder coating is designed only as a second top coat over a base-coat colour. If seeking a similar appearance to 'natural' mild steel with a durable finish, there are several standard gunmetal and grey powder coat colours available to provide or get close to the desired effect.
Clear coating alone is formulated for internal use over brushed aluminium and brushed stainless steel. Due to its limited durability performance, we do not consider it suitable over mild steel for long-term use.
It is also worth noting here that the aesthetic finish of mild steel can be affected by the degree and condition of mill scale on the substrate surface.
Long-term Care of your Powder-coated Product
Modern powder-coating processes provide a surface finish that is attractive and durable. But once installed, your powder coated products should not be ignored. To keep them looking good and working well for years to come, some regular maintenance is recommended. Leading powder coat supplier Dulux has some handy tips for caring for your powder coated article or joinery.
In taking care of powder coated items, it is important to be mindful of unintended consequences. Here's a powder coat story about one customer whose diligence created issues when combined with an installer's oversight.
This is only a brief outline of our requirements and recommendations to you, our valued customer. We are here to assist with particular issues around powder coating your products and components, and will always endeavour to eliminate or reduce any risk there may be. Through increased awareness of potential problems on all our parts, we can maximise our product quality and service efficiency.
We greatly appreciate and value your continued business.