Powder coating is a dry finishing process that has become extremely popular since its introduction to North America over 40 years ago. More and more companies specify powder coatings for a high-quality, durable finish, allowing for maximized production, improved efficiencies, and simplified environmental compliance.
Powder coatings are based on polymer resin systems, combined with curatives, pigments, leveling agents, flow modifiers, and other additives. These ingredients are melted, mixed, cooled, and ground into a uniform powder. A process called electrostatic spray deposition (ESD) is used at AP Coating to achieve the application of the powder coating to a metal substrate. This application method uses a spray gun, which applies an electrostatic charge to the powder particles, which are then attracted to the grounded part. After application of the powder coating, the parts enter a curing oven where, with the addition of heat, the coating chemically reacts to produce long molecular chains, resulting in high cross-link density. These molecular chains are very resistant to breakdown.
In addition to finishes, the powders are available in a variety of chemistries to maximize flexibility, improve edge coverage, affect material thickness or reduce the Faraday cage effect of using a static charge in the application. We work with our customers to identify the best powder for their product.
In order to guarantee the quality of our finishes, there are certain Quality Control methods we use to check the deliverable.
The thickness for the coating maintained is approximately from 50 to 100 microns or as per product requirement. (Digital Coating thickness measurement instrument used)
By adding weight to the coated object, it should withstand 3000 to 4000 grams. (1 to 5 kg. Pin type testing.) Adhesion test
Cross Cut hatch & Tape used.
Is powder coating durable?
Yes. Powder coating is generally more durable than any other paint application. It provides better protection against rust, corrosion and resistance against the toughest conditions, keeping its original polished look. This is why powder coating is the main choice in the aerospace and marine industry.
There are many types of powder, each with its own strengths and weaknesses. Outdoor powders are meant to withstand rain, snow, heat, cold and ultraviolet rays. They can also provide enduring rust inhibiting qualities, thus protecting the parts intended look and feel. Indoor powders cater more to the conditions relating to indoor use. Chipping, scratching and every day wear and tear are no threat to indoor powders. They come in a variety of special mixtures, providing a custom balance between maximum durability and many unique textures looks. When deciding which powder is right for you, we take into account what we are powder coating and how it will be used.
What is your turnaround time?
This depends mostly on the size of the job but two weeks is our average turn around time. We generally don't do rush jobs since our emphasis is long-lasting quality, not speed. All orders are completed in the order they are received.
Does new steel need to be sandblasted?
We highly recommend sandblasting for any parts that will be exposed to the elements; that is any project that will have outdoor use. Otherwise, it will go through a thorough preparation process before it is coated.
Can you powder coat parts that have been previously treated? What about galvanized parts?
Yes. We can remove any old finish, dirt, rust and anything else that might be on the surface of the part until it is ready to re-coat. Once we sandblast the previous coating to bare metal, it becomes an excellent candidate for powder coating. Galvanized steel parts can be powder coated as well, at AP Coating we have completed a couple architectural projects with this process several years back, which remain in excellent conditions today.
Should I have my parts sandblasted before bringing them to you?
Although you can have your part sandblasted before you bring it to us, we do not recommend it. After a part is sandblasted it is bare and exposed to the elements. Any moisture in the air will cause your part to begin surface rusting. This may not be very noticeable to the naked eye, but the presence of this microscopic surface rust will compromise the adhesion of the powder. As a complimentary part of our service, we provide pick up and drop off service from our associated sandblasting vendors. This usually minimizes the time your bare part is exposed to the elements, and guarantees the best possible adhesion of the powder.
What about holes with threads and other areas that need to stay coating free?
We can mask/plug off areas that do not need to be powdered. We can also apply high temperature masking to special surfaces such as threads or high tolerance areas to keep them from being coated.
Can you implement textures?
Yes. A constantly increasing variety of textured surfaces and wrinkles are available. Not only can we give parts texture, but we also have the ability to create veins and hammer tones. Veins and hammer-tones are streaks of alternate colors that appear throughout the part, which adds a professional look and added dimension to the piece. With powder coating, the finishes are almost limitless.