When you want to achieve the highest level of anything, we can agree that taking steps are critical to achieve the goal.
To achieve greatness, you should follow these steps every time you start the process. Following a well defined
process helps ensure you will experience success more often than not.
So how do powder coaters produce a flawless finished product? Why do problems happen at certain stages of the
powder coating process that leave your product looking less than ideal? What can your coater do to ensure you get
what you expect when you give them a job?
In this article, we’ll take a look at the 4 critical steps in ensuring the highest quality coating. By classifying and
preparing the substrate, you’ll take the necessary steps to ensure the coating you apply will last. The coating process
itself requires precision. If the product is not cured, everything you had done before may end up lacking in quality.
Our goal is to educate you on the importance of these 4 steps. These can make sure your items get coated well the
The first step to achieving the highest quality coating is to identify the substrate. The substrate is the underlying
substance on which the coating process will occur. Once you identify what material the coating process will be taking
place on, you can then understand the proper way to coat the material.
This is especially critical because there is no one proper way to coat all the different substrates out there. For
example, we use epoxies as corrosion protection coatings for factory-applied metal applications. They exhibit
excellent adhesion to metals and offer high moisture-, chemical-, and impact-resistance. Knowing that you have this
type of substrate gives you a better idea of the type of coating you’ll need to achieve the highest quality coating.
The second step in achieving the highest quality coating is to prepare the substrate. Now that you know what you’re
going to coat, you’ll need to prepare it. This will give you a sort of blank canvas with which to coat. You’ll regain
integrity in the substrate by ensuring proper preparation.
Within the preparation step are many, smaller steps that should to consider. They are:
- Disassmebly – If the product (substrate) is in one solid piece, this step is not necessary. But, if there are many pieces connected to each other, taking them apart will provide the best solution for preparation.
- Cleaning – This step is critical. Proper cleaning of the substrate is vital in eliminating flaws and producing a near perfect coating. Removing any unwanted dirt, oil, grease, etc. is necessary in this step.
- Stripping – This is another important step in the preparation phase of powder coating. This is especially true if the product has been powder coated before. Depending on the type of coating used prior, sandblasting might not be enough to remove old coatings. This is where a chemical stripping agent comes in handy.
- Sandblasting – While sand is one of the more popular mediums used in removing an old coating in preparation for a new one, it isn’t the only option. Along with glass and sponge, blasting with sand removes most hard to remove coatings applied previously. Sandblasting is also helpful as it leaves behind a texture on the surface of the part which allows a new powder coating to stick.
- Masking and hanging – These steps complete the preparation phase. Masking the substrate keeps the powder coating from getting to areas where coating can be harmful, such as threading. If threading is powder coated, it will not be able to go back together with it’s companion parts. Hanging is necessary as it exposes the highest possible percentage of the substrate for coating. This promotes a flawless product.
The majority of the time consuming work that goes into powder coating will take place during this phase. Taking
shortcuts during this phase increases the chance of a poor finished product, which can be difficult to restart from.
This step is the one that gets the most attention. This is likely because it’s the most intriguing aspect of powder
coating. Here, we’ll try to take a pretty scientific process and break it down into it’s simplest form. After breaking it
down, we’re sure you’ll love it as much as we do.
The coating process starts with knowing what it is that needs coated and making sure it’s prepared well. After taking
these two steps, a free-flowing dry powder is applied electrostatically. It’s then cured under heat. This curing process
allows the powder to “flow” and form a skin-like layer over the surface of the substrate. While we’ll dig deeper into
the curing process later, there is a lot of information about the coating stage.
Powder coatings come in countless types. Achieving the most amazing coating ever means finding the correct powder
for the substrate. For example, powders of an epoxy type are very well known. Epoxies provide a smooth and
consistent finish. Epoxies also have a strong resistance to corrosion and chemicals. But, epoxies are unable to
withstand lots of UV exposure. This limits their use on exterior-based products.
Polyester powders show significant resistance to UV exposure. They offer strong adhesion properties and excellent
gloss retention, even when exposed to the elements. Polyesters are often found on outside fencing, outdoor
decorative items and lawn and garden furniture.
Although there are many other powder types to consider, it’s important to know how each interact with its
environment once applied. Knowing where your coated item will be and what functions it will serve will go a long
way in ensuring you achieve an amazing coating.
This final step is what, to us, makes powder coating so interesting. Only after the curing process is complete can
someone believe that powder was first sprayed onto the metal surface to achieve this result. Without baking the
powder at extreme temperatures for an extended period of time, most would picture spraying water from a hose to
wash a car and all the water dripping off. But this is the last step.
Unlike painting, powder coating requires a curing process to finish the coating. While painting works well in
particular applications, the curing of a powder coating is what makes it a favorite in lots of various situations.
Curing takes place when a sprayed-on powder is exposed to elevated temperature. At these temperatures, the powder
begins to melt, flow out, and then chemically reacts to bond into a network-like structure. This curing process, also
called crosslinking, requires a certain temperature for a certain length of time. This establishes the full film
properties for which the powder was designed.
Powders normally cure at 200 °C (390 °F) for 10 minutes. The curing schedule could vary according to the powder
manufacturer’s specifications. Energy applied to the product for curing can occur using convection cure ovens,
infrared cure ovens, or by laser curing process.
And there you have it. The 4 steps to achieving the most amazing coating…ever. Identifying the material helps
determine the best way to prepare it. After removing any imperfections in the preparation stage, you’ll be ready to
apply the proper coating. Be sure to decide on the proper powder for the application to extend the life of the item
being coated. Lastly, curing the coating finalizes the chemical process that establishes the proper barrier that will
protect your property for years to come.