Powder coating is a type of coating that is applied as a free-flowing, dry powder. The coating is typically applied electro statically and is then cured under heat to allow it to flow and form a “skin”. The powder may be a thermoplastic or a thermoset polymer.
It is usually used to create a hard finish that is tougher than conventional paint. Powder coating is mainly used for coating of metals, such as household appliances, aluminum extrusions, drum hardware, and automobile and bicycle parts.
Powder Coating: The Ultimate FAQ Guide
Powder coating refers to a decorative coating applied to metallic products as free-flowing dry powder.
Essentially, this resilient coating is somewhat similar to paint, but it offers a more consistent appearance with reduced processing time.
This guide answers some of the common frequently asked questions about powder coating to enable you to understand and subsequently make an informed decision.
- Why Should You Consider Powder Coating Technology?
- What Are The Major Steps Involved In Powder Coating Process?
- What Are The Ideal Types Of Powder Coating Processes Available?
- What Are The Suitable Product Size For Powder Coating?
- Is Powder Coating Better Than Liquid Paint?
- What Is The Overall Longevity Of Powder Coating?
- What Are The Suitable Colors Available For Powder Coating?
- What Is Powder Coating Pretreatment?
- Can You Apply Powder Coating On-Site?
- What Are The Available Powder Coating Surface Finishes?
- How Long Does Powder Coating Take To Cure?
- Is Powder Coating Environmentally Friendly?
- Does Priming Come Before Powder Coating?
- Can You Recoat Over Existing Powder Coat?
- What Are Vital Processes For Attaining Efficient Powder Coating?
- What Material Can You Powder Coat?
- Can You Powder Coat Water-Damaged Aluminum?
- What Is The Maximum Temperature Powder Coating Can Withstand?
- Can You Powder Coat Over Painted Surface?
- Is It Possible To Make Custom Color With Powder Coating?
- How Does Powder Coat Stick On Product?
- Why Is Oven Necessary In Powder Coating?
- What Is The Average Turnaround For Powder Coating?
- How Much Does Powder Coating Cost?
- What Are The Disadvantages Of Powder Coating?
Why Should You Consider Powder Coating Technology?
Powder coated aluminum
This coating technology offers a broad range of advantages, making it an ideal choice to consider for your respective application.
Some notable benefits of powder coating include the following;
- It is a technology that barely contains solvents, and if any, it releases little or no volatile Organic Compounds into the atmosphere.
- Powder coated products, in general, have fewer appearance inconsistencies between vertically and horizontally coated surfaces.
- You attain faster curing time with powder coating, which is quite significant, especially in applications where time is a concern.
- Powder coating allows you to attain relatively thick coatings than traditional liquid coatings without sagging or running.
- It is easy to accomplish a broad range of specialty effects using powder coatings, which can be difficult to attain with other coating processes.
- Powder coating process is quite straightforward hence does not necessarily require thorough training or skills to achieve.
- Heavier coating weights as a result of powder coating process enhance corrosion and wear protection of the product’s surface.
- Powder coatings are compliant with relevant environmental legislation thus safe to use in various applications.
What Are The Major Steps Involved In Powder Coating Process?
Technically, powder coating entails three primary steps as follows;
Part And Equipment Preparation
This phase involves removing different impurities and unwanted compounds from the surface material of the product.
Such substances include oil, dirt, metal oxides, greases, and welding scale among others.
You can do part preparation using different chemical and mechanical means depending on size and material of the product.
However, in relatively high-end applications, the part is electrocoated following pretreatment process and consequent to powder coating application.
Alternatively, sandblasting or abrasive blasting can be used to prepare the part’s surface.
In a nutshell, various powder coating applications may demand different part preparation.
Powder Application Process
Once the part’s surface is ready, the next process is applying the powder compound.
Powder coating processes are quite several; hence the ideal approach will depend on the specific product you are powder-coating.
Immediately the powder application process is over; the product goes through a curing process.
This stage requires a specific temperature for a particular period to attain a full cure and establish complete film properties.
However, curing schedule could vary depending on the manufacturer’s specifications.
What Are The Ideal Types Of Powder Coating Processes Available?
Metal powder coating process
It varies based on the specific application, type, and condition of the product you are powder coating.
However, the main type of applying powder coating on surfaces is spraying using spray guns.
Majorly, electrostatic guns and tribo guns are the common types used in spraying method.
Another ideal type of powder coating involves using specific dedicated electrostatic discs.
Ordinarily, these discs are attached to devices producing static electricity at high voltage and low current.
Such discs powder-coat metal surfaces using the specific coating compound depending on type of material.
The third common technique of applying powder coating is known as electrostatic fluidized bed coating.
It involves heating the substrate and dipping it in an aerated, powder-filled bed.
In this process, the powder sips and melts into the surface of hot product but requires further heating to attain curing and coating.
Another powder coating method is known as electrostatic, magnetic brush coating.
It is primarily a coating method designed for flat materials and applies powder using a roller.
As such, it enables comparatively high speeds and precise layer thickness, often between 5-100 microns.
What Are The Suitable Product Size For Powder Coating?
Generally, it depends on the specific manufacturer you seek the services from.
Most companies powder coat products with a maximum dimension of 84 by 84 by 204 inches.
However, this may vary based on the capacity the specific facility can handle.
Importantly, you need to inquire from the specific company to establish the exact dimensions of product size they can powder coat.
Is Powder Coating Better Than Liquid Paint?
Essentially, powder coat hardly requires a solvent to keep the binder and filler parts in a somewhat semi-liquid suspension form.
Besides, powder coating is applied electrostatically and cured under controlled heat to flow and create a hard film layer.
Hence, powder coating forms a durable, thicker, and more resistant layer, reducing peeling, scratching, and fading.
What Is The Overall Longevity Of Powder Coating?
Typically, powder coated finishes are often baked on plastic finish, which is somehow thicker and stronger than liquid paint options.
Moreover, this finish tends to be more resistant to scratches, chips, and wear than liquid paint alternatives.
Thus, it is regarded as more durable in a wide range of product applications.
Generally, this finish can last for at least 10 years and up to many decades, a clear indication that it is indeed durable.
Even so, since coating process often involves different variables, the actual durability depends on application conditions.
Additionally, you need to take care of the product to protect the coating during handling.
You also need to avoid exposing it to harsh chemicals or conditions likely to damage it to attain better longevity.
What Are The Suitable Colors Available For Powder Coating?
Powder coating provides a wide range of standard color and texture options.
You can also find specialty colors upon request.
Besides, you can get custom color for your application at an additional fee.
Of course, this is fundamental because it makes it possible for you to go for the right color that suits your demands.
In a nutshell, you can never run short of a specific color that meets your requirements because they are available in plenty.
What Is Powder Coating Pretreatment?
Powder coated metal
It is the process of through cleaning part surfaces to eliminate dust or particles likely to interfere with final finish.
Different manufacturers use various powder coating treatments in their processes.
For instance, a common method known as an 8-stage system cleans the parts and enhances the bond with the specific powder coating finish.
Furthermore, rapid drying techniques are also integrated to inhibit part corrosion.
During part pretreatment, a chrome-free zirconium seal improved with saline technology is applied to create a firmer grip with powder or primer.
Can You Apply Powder Coating On-Site?
This coating process is applied at the factory since it requires specialized equipment.
Some notable equipment used in factory powder coating process includes a spray booth, electrostatic spray gun, and oven for curing the coating.
Hence, on site application is not necessarily possible since the hot curing cycle is needed to fuse the coating.
It implies that onsite powder coating is likely to lack excellent quality control, which is critical in this process.
What Are The Available Powder Coating Surface Finishes?
Powder coating surface finishes are available in different categories, which include the following;
This type of powder coating surface finish becomes liquid and relatively soft when heated.
In essence, this eliminates chemical bonding making the process reusable and reversible.
Moreover, thermoplastic powder coating surface finish are thicker thus, more durable.
As such, you can consider it in a host of applications, including consumer electronics and auto-parts among others.
It is a relatively different type of powder coating surface finish in the sense that it creates chemical bonds immediately it cures.
Hence, this makes it difficult to recycle it.
However, it is an ideal option to consider in high heat applications since the bonds prevent it from melting away.
Also, it is more affordable than a thermoplastic powder coating surface finish.
Zinc-based Powder Finish
This type of powder coating finish is made from zinc-rich epoxy thermosetting powder.
It is designed to prevent rust and any moisture-related damage on iron-based parts and components.
You can also use this finish as an undercoat for other finishes for added effect.
It is a powder coating finished designed for applications where retaining same color and gloss of the application is a concern.
Once applied, this finish becomes completely resistant, and it is immensely difficult to remove with abrasive motion.
Hence, it is suitable for a wide range of industrial applications since it eliminates or minimizes maintenance needs.
How Long Does Powder Coating Take To Cure?
It depends on a lot of factors, but generally, it takes about 15-30 minutes.
Ideally, once the product is prepped appropriately, it is placed in the oven.
Hence, when the product reaches the target temperature, powder flows out and cures in about 15-50 minutes.
Immediately you remove the product out of the oven, and it cools down; you can put it back into service immediately.
Is Powder Coating Environmentally Friendly?
Powder coating process is relatively safer for the environment than paint.
Ordinarily, powder is non-toxic and, in many instances, emits little or no amount of VOC.
Besides, reputable manufacturers often tailor this process with the environment in mind.
Hence, during the process, most of the wastewater is often evaporated.
Also, drying and curing process of powder coated parts in most efficient ovens and burners.
Moreover, excess powder in the process is usually reclaimed and utilized, making powder coating eco-friendly.
Powder coated aluminum profile
Does Priming Come Before Powder Coating?
Ideally, priming part surface is essential since it extends the product’s longevity and coating.
Material such as aluminum provides natural resistance to rust and corrosion.
However, it can still suffer rapid deterioration due to corrosion if it comes in contact with another metal product due to conflicting properties.
Moreover, most metals tend to be cost-effective and easy to work with but often rust rapidly when exposed to various elements.
Therefore, priming such materials becomes fundamental in preventing corrosion and rust.
Nonetheless, it is important to use recommended priming substances for specific materials to attain desired results.
Can You Recoat Over Existing Powder Coat?
However, several factors determine the ultimate results since the recoating products are less certain than finishing new or sandblasted materials.
Generally, clean powder coated products that are free from rust, contaminants, and corrosion exhibit a significant chance of successful recoating.
Re-coat tasks require implementation of several product specific measures to increase chances of successful coating results.
Even so, potential for defects and contamination of the surface or underlying coating, there is no guarantee of longevity of the recoated material in different applications.
Moreover, this approach is not advisable, especially if the customer demands “As new” surface finish.
However, it can be ideal for clients aiming to bring fresh life to an old coating at cost-friendly rates.
What Are Vital Processes For Attaining Efficient Powder Coating?
To attain an effective powder coating process, it is imperative to consider a few basic practices.
Of course, some of these practices may depend on a specific process to complete your item.
Some of these processes include the following;
- Pressure and heat of a heat gun can deform a thin sheet metal; hence not recommended.
- Severe corrosion and fillers within the product and an existing coating may cause depressions or holes in product finish.
- You must degrease products thoroughly to remove oil, grease, and other lubricants for further processing.
- Seal welded compartments in products require some holes to enable free entry and drainage of chemicals for pretreatment.
- Products must be free of stickers and permanent markings or adhesives since such compounds are not easily removed by pretreatment chemicals.
- Oven temperatures are often elevated, thus ensuring products are free from low melting point metals. It prevents the product from losing strength.
What Material Can You Powder Coat?
You can powder coat a wide range of conductive metal surfaces such as those made from aluminum, steel, zinc, magnesium, etc.
Technically, you can easily powder coat any metal item, which can endure baking temperatures of up to 200° C.
Most powder coated items are used in our day-to-day lives without noticing.
Some of these items include bicycle frames, washing machines, roof racks, bulbar, fencing, awnings, security screens, metal furniture.
Can You Powder Coat Water-Damaged Aluminum?
Water-damaged aluminum material can barely be treated effectively through standard process.
Ideally, it requires prior physical removal of all parts damaged by water using mechanical or abrasive means.
Most companies often remove water-damaged areas from the material at additional cost.
Therefore, you need to inquire from the manufacturer to establish whether they offer such services for water-damaged aluminum materials for powder coating.
What Is The Maximum Temperature Powder Coating Can Withstand?
Ordinarily, powder coating is cured at immensely high temperatures.
However, the design of this coating is not essentially suitable for exposure to elevated temperatures for a more extended period.
Hence, the ideal optimum temperature recommended varying based on powder and manufacturer.
Besides, powder coating is designed for environmental conditions of relatively less than 70° C.
Exposing the material to a temperature beyond 70°C may lead to degradation of the finish over time hence discouraged.
Can You Powder Coat Over Painted Surface?
Powder coating over paint is not necessarily designed to withstand exposure to high cure temperatures within the oven.
Moreover, paint finishes designed for powder coating are limited and generally restricted to metal primer paints.
Hence, as a general rule, you cannot apply powder coating over paint.
It is the reason any reputable and professional manufacturer would generally remove any paint from metal surfaces using abrasive methods before powder coating.
Is It Possible To Make Custom Color With Powder Coating?
Notably, powder coating finishes are often sprayed on in form of a solid powder.
Hence, unlike liquid paints, it is difficult to mix and attain color by finishers.
But numerous standard colors are available from reputable powder manufacturing companies.
Besides, if colors from standard range are unavailable or do not meet your application’s demands, you can order custom colors.
How Does Powder Coat Stick On Product?
Powder coated zinc die cast part
Essentially, powder coating is often applied through electrostatic spray process.
In this process, solid powder compounds are charged up to high voltage through a dedicated spray equipment.
Therefore, the part being powder coated is connected to ground.
Consequently, the charged elements are attracted to and stick to the product using forces formed from a static charge of powder particles.
Coated area is then baked in an oven at increased temperature to melt and cure coating into a consistent product coating layer.
Why Is Oven Necessary In Powder Coating?
Ideally, powder coating entails applying a thermosetting plastic layer in powder form to metal using an electrostatic spray process.
Hence, to transform the thermosetting plastic into a strong, consistent finish, it is imperative to heat the products in dedicated ovens.
The heat inside the oven allows applied powder to melt and form a uniform layer as it undergoes a chemical reaction to yield a hard coat.
What Is The Average Turnaround For Powder Coating?
Ordinarily, it depends on specific steps needed to powder coat your product or item and service priority you need.
In general, though, a turnaround for standard service is often relatively fast but varies based on the following factors;
- Order quantity
- Part design (simplicity or complexity)
- Pending orders
However, in most instances, manufacturers often provide express priority options if you need an order urgently.
Express priority makes it possible for you to obtain the order within shortest time possible irrespective of the prevailing circumstances.
This may be between 2-7 working days.
But it is always important to inquire from the company to determine the exact turnaround period, whether standard or express priority.
How Much Does Powder Coating Cost?
It varies based on a host of factors.
But the major aspects which determine the cost of this process include the following;
- Part design
- Order quantity
- Preferred turnaround priority (standard or express priority
What Are The Disadvantages Of Powder Coating?
This process has a few shortcomings, which include the following;
- Relatively challenging to obtain thin films compared to liquid paints
- Exhibits a slower color changing, and this provides a few inefficiencies
- You can hardly mix powders to attain different colors
Contact us today for the best powder coating.