Across many industries and applications, there is a common need for finishing processes that can offer effective and efficient protection for metal surfaces. Whether it’s pipeline for the oil and gas industry or traffic signs in urban development, metals are ever-present in our daily lives, and they need to be protected from damage from a variety of sources. Traditional wet paint can be used to coat metal surfaces and afford some protection, but there are more effective coating technologies—powder coating being first and foremost amongst them.

Powder coating in Houston offers several advantages over wet paint application. One of the clearest advantages with powder coating is the thick, hard finish that is produced by a process of electrostatic binding and high-heat curing. The thickness of the coat, and its durability and resistance to factors such as abrasion and rust, is unattainable with traditional wet paint coatings. Plus, wet paint coatings will require maintenance down the road, with further coats necessary to preserve the coat’s protective qualities; powder coating is a more permanent solution, offering a denser and harder finish with fewer coats overall.

Powder coating doesn’t just offer protective benefits, but in several ways it can also offer a more attractive finish. Powder coat colors and textures are offered in a wide variety of choices to the consumer, with the RAL system providing standardized colors throughout the industry. Powder coating in Houston also offers a more even coating since the powder is applied uniformly without the drips or application traces that might be seen with wet paint. Plus, the application and curing process in powder coating is significantly faster than allowing a coating of wet paint to dry, and powder coating is environmentally friendly—the powder contains no solvents and produces a low amount of volatile organic compounds (VOCs).

Maybe your outdoor furniture has been sitting exposed to the elements for too long. Maybe you just found a great deal on furniture that needs refinishing at a garage sale. Either way, it’s usually fairly obvious when furniture is in need of refinishing, especially outdoor metal furniture. However, before you make the decision on whether or not to refinish, and the method of refinishing, there are some important things to consider.

First: do you actually want to go through with the outdoor furniture refinishing? This question might be especially relevant if the furniture was purchased in its current state, such as from a garage sale or an antique store. Vintage styles are currently popular, so if the piece isn’t too damaged, it might be worth keeping it in its current state for the “charm” factor. However, rust and sharp edges can quickly make a piece of metal furniture unusable, so don’t be shy about getting it refinished.

Once the decision is made to go through with the outdoor furniture refinishing job, additional factors crop up. Is it worth doing the job on your own? DIY refinishing jobs can be rewarding, but also costly in materials, labor, and most importantly, time. If the furniture piece isn’t a labor of love, then getting it professionally refinished is likely the best option.

A new oilfield assembly or refinished piece of furniture might look great as a final product, but there’s a lot of work that goes into making sure its surface is prepared before the coating is even applied. If a substrate’s surface is dirty, the coating will not adhere properly and will ultimately fail. To prevent this from occurring, multiple industry-wide surface preparation standards have been developed to clean and properly prepare different types of metal. Given that there are so many different potential cleaning methods and surface materials, these guidelines benefit the industry by standardizing processes and ensuring the highest possible quality for the client.

The most commonly used and accepted standards were put forward by the Society for Protective Coatings (SSPC) and the National Association of Corrosion Engineers (NACE), both professional organizations operating in the corrosion and coatings industry. These organizations came together to bring the Joint Surface Preparation Standards to the industry. These standards cover a multitude of techniques for preparing surfaces, from simple solvent cleaning (SSPC-SP1) to abrasive blasting using a high-pressure gun that leaves a metal surface “uniformly free of all foreign matter” (SSPC-SP5 / NACE 1).

Note that these surface preparations also create anchor profiles from which the powder adheres to the metal. The more aggressive surface preps will produce a deeper anchor pattern. Typical steel grit blast media will produce anchor profiles between 2-4 mils. Mild solvents and hand-etching will produce less. Recognize that the classification numbers of the surface preparation standards do not necessarily increase with intensity (so read them carefully).

Polyester powder coating technology has been around since the 1970s and accounts for 30-45 percent of powder coating product sales globally. There are two main categories of polyester powder coatings used in the industry today: TGIC (an acronym for the chemical compound curing agent it uses, triglycidyl isocyanurate), and HAA. HAA polyester powder coating uses β-hydroxyalkyl amides as its curing agent and is often called TGIC-free or Primid polyester powder coating after the brand of curative used in most HAA powder coatings. While both categories of polyester powder coatings perform relatively similarly, there are some pros and cons that can tilt a company toward one or the other. 

TGIC coatings typically offer better chemical resistance and corrosion resistance than their TGIC-free counterpart. The HAA curing mechanism can release water, which makes the coating slightly more water soluble than TGIC-polyester. Because of its slight water-solubility, HAA coatings are more susceptible to acidic and alkaline chemicals. All of this makes HAA-polyester less corrosion resistant than TGIC-polyester.  However, with different formulations, a Primid polyester coating can perform on par with TGIC. When it comes to impact and abrasion resistance, flexibility, and hardness, TGIC and TGIC-free polyester powder coatings are the same. 

For application and curing, TGIC-polyester cures at a lower temperature than HAA-polyester (roughly 290 degrees Fahrenheit and 330 degrees Fahrenheit respectively). Many companies find HAA-polyester applies more easily and sticks to nooks and crannies better than TGIC-polyester. Thickness of application varies greatly between the two, with TGIC-polyester coating able to reach about 10 mils (250 microns) thickness and HAA-polyester coating reaching 3.5 – 4.0 mils (90-100 microns) thickness. When it comes to color stability, TGIC-polyester comes out ahead. HAA-polyester can yellow in color in overbake conditions, while TGIC-polyester has very little color drift over a wide range of cure times and temperatures.