When customers go to the store, they need to know how many gallons of paint to buy to cover the area they wish to paint. They also want to know how many coats it takes to completely hide what they are painting over. The spreading rate of a paint is how to determine how “far” a paint will go by quantifying how much area is covered for a given quantity of paint. Sometimes to compare paints, a researcher will use the same spreading rate for two different paints and then compare the hiding power visually using the background of the drawdown chart as a guide or instrumentally using a spectrophotometer.
Paint produced by the architectural paint industry must perform on a wide range of substrates. Some examples are previously coated wallboard, from glossy to flat, wood trim, plaster, uncoated wallboard, stucco, etc. The porosity of these substrates varies greatly, yet the paint must maintain the same color and gloss appearance no matter the substrate.
When we evaluate paint, we ask, “how much paint must be applied to hide the substrate below it?” or “does this paint hide better than that paint?” Opacity is a paint’s ability to prevent the transmission of light in order to hide the substrate below it. Throughout the paint industry, the terms hiding, opacity and contrast ratio have frequently been used interchangeably. Hiding is a general term used to describe all of these concepts, including hiding power. However, hiding power also takes into account the spreading rate of paint and will not be discussed here. (More information on hiding power can be found in ASTM D 2805.) More…
“This is bad news, Hal.” The contractor looked up from his plans and walked over. Luke was crouching, inspecting the rivets and bolts at the base of the complex valve system that delivered chemicals from transport trains into the factory. Luke continued, “There’s corrosion all over this system. Normally, that might not be a big deal, but it looks like someone else kept painting over the damage instead of fixing it. Look at this!” Luke ran a magnet over the painted surface. At some points, the magnet held tight to the coating, but at other points, the magnet fell to the floor. Even through the top level looked well-painted and clean, the substrate underneath was telling a different story.
Hal protested, “Come on, Luke. It looks fine from here.” Luke continued his objection: “The metal under the paint is in bad shape and it’s likely getting worse. Maybe it holds up ten more years…or maybe it starts falling apart next week. If you insist on doing the work without addressing the underlying problem, then I suggest you find another painter. I’m not doing it.”
Paint sprayers have revolutionized how professional painters work. Sprayers are considered as much as ten times faster than using a brush. Think about that: a traditional paint job can be accomplished in a fraction of the time needed to use a brush on the same job. The downside, however, is that to achieve these results the painter must be using the right paint sprayer. Considering the number of parts and pieces working together in a paint sprayer setup, it can be very difficult for even the most seasoned and experienced paint professional to know what the right setup is for the work they are doing.
It should come as no surprise that paint sprayers come in a variety of different sizes and styles. It should also come as no surprise that different sprayers carry different costs, not just for upfront purchase, but also ongoing maintenance and use. The correct sprayer can pay for itself quickly, but have you ever stopped to research the sprayer you are using as a professional painter to confirm that it is indeed the best option for you? It is possible – even likely – that the paint sprayer you are using is not optimized for the work you do.
Clyde and his younger sister Ellie grew up in Taylor, Texas. The town had changed a lot in the last fifty years, but one constant was the ante-bellum mansion just off the main street in town. The lady that lived in the house since the early sixties had passed away and the house was put up for sale. The city discussed purchasing the house and making it a museum celebrating the county’s history but ultimately couldn’t find the money in their budget. The home sat vacant for months with a for sale sign in the yard.
One evening while Ellie was over for dinner, Clyde had a wild idea. “Let’s do it. Let’s buy the place and fix it up. Why not? It’s part of our history and the price is right. I’m sure it will be a lot of work, but can you imagine the pride we would feel, the pride the whole town would feel for the house to be restored?” Ellie didn’t take much convincing: “That’s a great idea.”
The next morning Clyde made a call to the bank, the county courthouse, and the realtor on the sign. Three weeks later, he and Ellie owned the place and they were ready to start the work of restoring the home to its previous condition. But restoring a historic home is far from an easy task…
The job should have been simple: four bedrooms in a one story suburban house. The client was preparing to put the house on the market and wanted all of the bedroom walls to be a calm, natural color. Jesse and Sal scheduled the job for a Tuesday morning and figured that by working together they would be done in a day, no problem.
But Jesse failed to take into account that three of the bedrooms belonged to young children. As such, the walls were painted bright colors like purple and orange, and they were full of pin holes from Mickey Mouse posters and other keepsakes tacked to the sheetrock. As they prepared the drop clothes, taped off the doorjambs, and got to work priming the walls Sal turned to Jesse and commented, “With the time it takes to prime the walls, let them dry, and then paint….we may not get this done in one day.”
When you’re a professional painter, choosing the right tools for the job is every bit as important as your paint skill. From knowing which type of bristle material is best to which type of clear coat gives the most protection and shine, the tools of your chosen craft are integral to your success.
So it’s no wonder that the people making the very paint you use – the chemists, mixers, and manufacturers – rely on a tool set that is every bit as varied and versatile as the tools you use when painting. From glossometers to spectrophotometers, from haze meters to grind gages, the tools and test measurement equipment used in paint factories around the world are how you know that the paint you’re using is as close to perfect as possible.
The development and creation of paint most often happens in a laboratory far away from paint stores and job sites. Chemists and scientists spend hours upon hours formulating the exact right combination of materials to make a paint that performs exactly as they intend. From holding color, to protecting the substrate, to adhering to the surface and not cracking for years on end, formulating a paint that can be utilized in a production environment is a rigorous and detail-oriented process.
In the laboratory, these scientists and engineers count on a number of tools to help them make sure that what they are making can be repeated on a large scale and utilized by professional painters on paint jobs all over the world. And while tools like spectrophotometers, adhesion testers, and gloss meters provide a wealth of information about a paint’s true chemical characteristics, this represents only half of the test equation.
Professor Magnuson stood in front of the class with a bucket of soapy water and a sponge. While his “Introduction to Painting” class watched on in silence, he dipped the sponge in the water bucket and began cleaning the oil-painting in front of him. Some of the students were dumbfounded and wondered why their instructor would do something that most certainly would damage the painting.