The Pros and Cons of Powder Coating
What is Powder Coating
To better understand the benefits and drawbacks of powder coating it is important to start with what it is. Powder coating uses coatings that are in a powder form and an electric charge to cause the powder to adhere to a surface. The coating is then baked at high temperatures which causes the powder to flow together, resulting in a coating that is durable and withstands the elements well. Powder coating is like any paint application process, it has its pros and cons. We will discuss the benefits and drawbacks of powder coating further in this article.
The Pros of Powder Coating
The pros of powder coating include that it has greater durability than most liquid applied coatings, is friendlier for the environment, in the long run can be more cost efficient, and is generally less flammable than an equivalent solvent based liquid coating. It’s environmental friendliness and long term cost advantage comes from the fact that powder that does not adhere to a target is collected, meaning limited to no waste of coating. Additionally, because the powder stays in the booth little to no VOCs are released into the atmosphere in comparison to solvent based spray coatings. Powder coating is also one of the most durable coating types, able to stand up to harsh elements as well as being relatively scratch resistant.
The Cons of Powder Coating
Despite all these positives there are some downsides to powder coating. These downsides include color change difficulties, difficulties applying a thin amount of coating, start up costs, difficulty touching up missed areas, the part has to be able to be grounded, and finish appearance. With powder coating each non adhered powder particle must be collected and can make color changes difficult as the collection area for the powder that does not adhere must be emptied each time a color is changed. Thin film builds (less than 6 mils) are hard to achieve with powder coating. This is due to the powder coating process and cannot be changed; essentially you have less fine control over the amount and speed which powder is applied to the target. If you need a coating build of less than 6 mils, powder coating is not the right fit for your painting process. Along the same lines, due to heavier film builds and the way powder coating is done, the finish quality is usually less fine than a sprayed coating. Powder coating requires the coating to be baked which allows the coating to flow together to form the surface finish. Due to the coating flowing together you have less control over the way the material smooths out. In liquid coating work you can control your atomization level which allows for the finish to be finer as you apply increased air. Due to powder coating not allowing for small film builds, touching up a part is generally not possible as well. With powder coating you will typically need to remove all of the original coating to achieve a quality finish, with liquid coating you can sand and prepare a portion of a product and achieve a blended finish that will be hard to tell apart from the rest of the product. Powder coating is applied electrostatically and therefore your target part must be able to be painted electrostatically. Finally, you have start up costs. With liquid coatings you only need a basic spray gun and a booth to be able to safely coat any product you want. However with powder coating, a powder coating oven, powder coating spray gun and a powder coating booth are required which can be a higher initial purchase. The expense of the powder oven often can be limiting as well to the size of item you can coat. Liquid coating can be applied in the open (this is not recommended but is possible) powder coating requires a booth and oven to be able to apply a coating to a part. Which means you will have to purchase an oven large enough to handle your product if you plan to powder coat.
If you’re considering powder coating vs liquid spray consider the following as a decision tree.
Do I need a thin coating layer (<6 mil coating) – you need liquid based coatings
Do I need a “class a” think car quality finish – usually you would use a liquid coating to achieve a car finish
Do I have limited start up capital- you may want to consider liquid coatings for your finish
Do I routinely have large parts – you may want to consider liquid spray if the item is so big that the oven would be extraordinarily expensive
Do I have a single color I use and want durability – go for powder coating
Do I need to watch the environment and have few color changes – go for powder coating
- I can afford a large upfront cost and want to save in the long run – go for powder coating as long as your product can be painted electrostatically because powder coating requires electrostatic application