What is a Paint Primer?
Primer or undercoating is a paint product that allows finishing paint to adhere to the surfaces properly. It contains a high concentration of solids and adhesive binder which act as a sealant and provides a smooth and clean area for the paint to adhere.
The application of primer in the material being painted increases paint durability and provides additional protection. Primers are usually white in color however they can also be some other neutral colors to provide a neutral surface and to show the true colors of paints. A primer consists of 20-30% synthetic resin, 60-80% solvent, and 2-5% additive agent. For better durability, some primers contain polyethylene (plastic). Compared to paint a primer is not intended to be used as the outermost finish and can instead be engineered to have improved filling and binding properties with the material underneath.
What Is the Difference Between Primer and Paint?
Primers and paints are different products with different purposes though they look the same in appearance. Primer is the initial base coat applied to the surface before painting. Paint and primer are both applied using a brush however primer act as the bonding agent between the paint and the surface. Paint is a pigmented liquid, liquefiable, or solid mastic composition that after application to a substrate in a thin layer, converts into a solid film. It is most commonly used to protect, color, or provide texture to objects.
When Does a Primer is Needed?
1. Painting porous materials including concrete and wood. Using a primer is mandatory if the material is not water-resistant and will be exposed to elements.
2. Gypsum board (drywall), it's standard practice to prime new construction drywall because it seals the wall from moisture to prevent mold growth.
3. Primers are used for dirty surfaces that cannot be cleaned or paint a light color over the dark finish.
4. Walls with stained surface needs to be primed. Stains such as old water damage or smoke stains from cooking. Primer acts as a blocker and seals the stains.
Surface with odor. Odors from smoking, strong-smelling food, fire, or smell from pets can be retained in the walls. These odors can be eliminated by applying high-quality primer.
5. Extreme change of color. Priming is necessary if you are switching color from a very dark to a very light color.
6. Untreated aluminum requires a primer. A primer designed for metal is highly recommended if a part is to be exposed to moisture. Once water seeps through the bare metal, oxidation will begin. Metal primers contain additional materials such as sacrificial zink which protects against corrosion. Metal hydroxides/oxides do not provide a solid surface for the paint to adhere to and paint will come off in large flakes.
7. Painting latex-based paint over oil-based paint. To gain better adhesion between switching with these two different paint-based chemicals.
Applying over new surfaces seals the original material so that the paint doesn't sink to it requiring extra coats. Primer with stain-blocking characteristics seals over mold stains and blemishes to stop from appearing from the finish coats of paint. For proper bonding of paint jobs, priming is necessary for masonry and many wood surfaces. Primers lay the foundation of your paint job, whether you are painting exterior or interior surfaces, primers ensure that the surface has a uniform texture so the paint adheres effectively.
Types of Primer
The best primer to use depends on what type of paint you are using and the surface you are painting. The key to a professional-looking job is using the appropriate type of primer. Get to know more about the different types of primers and where to use them.
Oil-based primer is primarily for metal, windows, cabinets, and doors. It is also known as alkyd primer and suitable for both latex and oil paints. Painters generally choose oil-based primer due to its versatility and it works well with almost all kinds of surfaces whether exterior or interior walls. It conceals the cracks and porous surfaces to have an ideal surface for the application of paint.
This is a water-based primer that is perfect for prepping unfinished drywall for painting. It is effective as an oil-based primer to cover stains from the wall and it makes the wall an even surface. It dries quickly, less susceptible to cracking and peeling, and can be cleaned easily. Latex-based primers are inexpensive and easy to apply.
Shellac primers work well to seal surfaces and offer great stain protection. They are perfect for covering smoke or water-damaged walls because of their excellent stain-blocking qualities. They are also ideal in preventing normal water, rust, smoke stains, and wood tannin bleeding. Shellac primer can be used with both latex and oil-based paints.
The application of primer solves a lot of paint problems and saves your time and money. Though applying primer may seem unnecessary due to its invisible purpose, the benefits of this essential step cannot be underestimated.