Some of you may have heard of the term powder coating if you’ve ever had a new set of railings or gate or parts of your bike recoated after an accident. But what exactly is powder coating and why is it such a good finishing process for casted metal parts?
Powder coating is applied as a free-flowing dry powder that, unlike a conventional liquid paint, does not require a solvent. Dry powder is usually applied through an electrostatic gun. The gun gives the powder a negative charge, which is attracted to the grounded metal form. Once the desired thickness is achieved the metal form is cured under heat usually in a curing oven. The heat causes the powder to flow and form thermal bonds between the powder particles. This produces a skin that’s tougher than conventional paint.
As well as its durability, powder coating is also more efficient in a number of different ways:
Firstly, powder coating contains no fluids to evaporate, and therefore does not emit any liquid elements or VOCs (Volatile Organic Compounds) making the process more environmentally friendly. Powder coating is completely dry and solvent free resulting in a process that doesn’t need expensive fume extraction or pollution control systems.
Roughly 50-70% of spray paint is wasted during application due to overspray and extraction. Powder coating has a much higher rate of transfer to the ‘paint’ surface. This results in a more efficient painting process. Unlike liquid paint, powder can be collected and reused.
Powder coating is incredibly durable and more resistant to chipping and scratching than liquid paints due to the thermal bonding created during the curing process. Powder coating, unlike paint, is made up of a combination of pigment compound, filler material and resin. This results in a surface finish which is incredibly smooth, glossy, highly durable and one that provides a superior colour retention.
The powder coating process is much simpler and more forgiving and can be applied in much thicker coats. With liquid paints, over spraying can cause ‘drips’ or ‘runs’ in the finish of the paint. Powder coating due to its dry nature will not allow that to happen.
A wide range of speciality effects such as gloss, metallic, flat and pearlescent are easily accomplished using powder coating. The powder can also come in a variety of pigments, usually in large batches of standard colours but colour matching can also be obtained.
At LCR we use powder coating not just for its durability on exterior products but also for the aesthetic appeal it delivers through the beautiful finish to our products. Although not completely necessary when applied to interior furniture we love the high gloss finish and array of colours we can apply to the furniture we create. The one downside is the initial outlay in terms of cost. Powder coating can be slightly pricey on application. As most fabricators, such as LCR, send their products off to foundries that specialise in powder coating there will be a small premium. Over time the primary outlay will be curtailed as powder coated objects have a much longer shelf life owing to all of the above mentioned properties.
For all enquiries about our products or for any bespoke projects you have in mind please contact LCR Fabrications today.