Few things are worse than finishing up a project just to realize that your paint isn’t sticking to the woodwork, walls, plastic, or metal as it should, or the dried project looks more like your kindergartener took a paintbrush to it. This is where primer comes in, and choosing the right primer is key to a beautifully finished project. If you’re looking for more information on the types of primers available and when and where to use each kind, you’ve come to the right place. We have also included a helpful FAQ at the end of the article to answer any further questions you may have. Happy priming!
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What is Primer
And why do I need it? Primer is essential for helping paint adhere to a surface and to prevent cracking and chipping. It also helps to give the paint a more even and finished look and can help to prevent stains and makes cleaning the paint a little easier in the future. Without primer, the paint will continue to soak into the surface of your project which will require more layers, and when it does finally dry you can expect to be peeling away layers of paint. Primer comes in three different types: oil-based, latex, or shellac, and the surface you are painting will determine the type of primer you need to use.
Oil Based Primer (Alkyd Primer)
Versatility is the name of the game for oil-based primers, as they are great for paint jobs requiring latex or oil-based paint. They can go on tons of different surfaces and are extremely stain resistant. Furthermore, if you’re painting over a surface that has heavy staining, oil-based primer helps to cover the stains up so they don’t show through the paint when you’re all finished.
Oil-based primer is excellent at withstanding temperature fluctuations, which helps if your finished product will need to be withstanding the elements. It’s also a great choice for the areas of your home that will have a lot of contact with little hands (such as walls, cabinets, or doors) because they help to prevent stains. Basically, if you have little ones at home an oil-based primer is going to be your best bet at sealing in stains that are already present and helping to keep stains off.
While oil-based primers might be great for those surfaces that you have frequent contact with, they do require a little bit of extra care and time. The dry time for this primer is a full 24 hours, and mineral spirits are required to thin it properly. Oil-based primer can also be more difficult to clean, as you can’t take water and soap to it like you can with other primer types. In addition, it is high in COV compounds, which have been under fire in recent years due to potential health impacts. There is also disposal requirements for oil-based primer and any brushes and other tools you use with it. You absolutely cannot pour it down the drain or into the ground and must dry it out before you dispose of it.
Do not use an oil-based primer on masonry. The surfaces ideal for this type of primer is raw wood, raw drywall and patched walls, and rough or stained surfaces. This primer is great with porous woods, so if you are using unfinished wood in a project this is definitely the primer you need. Keep in mind the 24-hour dry time mentioned above and make sure you allot for this during the planning of your project. To thin oil-based primer, add a small amount of mineral spirits and stir before applying. You should always use natural bristle paintbrushes when working with an oil-based primer to ensure a smooth, even coat.
Latex Primer (Acrylic)
Latex primer is water-based and a healthy alternative for those concerned with VOCs. Soft wood, bricks, and concrete are ideal for this primer type as the water base helps to give a thin and even coat before you apply paint.
The great thing about latex primer is that you can apply it to a multitude of surfaces, whereas oil-based primers have a limited amount of surfaces you can use it on. Latex primers are excellent for drywall, plaster, woodwork, metal, and masonry. It also has a very quick dry time, so you won’t have to wait long to complete your project. Allowing 3 to 4 hours to dry is all that’s needed before you can start painting away, although a test patch is often recommended depending on the type of material you are working with.
In addition, it’s more flexible and less brittle than oil-based primers so you won’t have to worry about your finished project cracking into pieces once you’re done or peeling away. It also contains almost no VOCs, and some contain no VOCs which makes it ideal for indoor work (especially unfinished drywall). While latex-based primer and latex-based paint are more susceptible to stains, the water-based component makes for easy clean up if needed.
Staining and poor coverage are the main issues with a latex primer. Unlike oil-based and shellac primer, latex primer and paints show stains much more easily. It also is not ideal for areas that are heavily stained, as it does not have the thickness and durability to cover stains quite like the other types of primers do. While it does have a quick dry time, you will still need to do a test area if you are using it on wood in order to see if it will cause the grain of the wood to raise. This does add some extra time to your project, but ensuring that the wood doesn’t get wrecked from the primer is very important to a beautiful finish.
Latex-based primer covers a variety of surfaces easily with a 3 to 4-hour dry time. It is readily disposed of and has little to no VOCs. Even though it is a healthier option, it is still important to keep the room aired out and a fan on to avoid any potentially harmful fumes. Make sure to do a test patch prior to a full application to ensure you do not ruin the wood if that is what you are working with. The best brush to use with latex primer is a synthetic brush.
This is your go-to for interior work as it helps to seal surfaces. It has tons of benefits and a limited amount of negative qualities, which is why it has been praised as an ideal primer for hundreds of years. It’s also great if you have pesky stains to cover up.
While the other primers listed have multiple hour dry times, shellac primer dries in less than an hour. This makes projects quick and easy to finish and, even if you decide you want to do a test patch, it won’t set your project back very long. Like oil-based primer, its excellent at stain blocking and assists in the cleaning process if stains or fingerprints start to show. It’s also one of the more ideal primers for covering up stains that are already present. Finally, it is adhesive enough that it sticks to a variety of surfaces, so any leftover primer can be used on other projects down the road.
There aren’t many complaints when it comes to shellac primers. While it does contain a larger amount of VOCs, most people overlook this due to the fact that it has an impeccable and almost unmatchable ability to give a smooth, even cover to surfaces prior to painting. It does require the additional step of thinning, but this is relatively simple. A small amount of denatured alcohol is required prior to application. Simply mix it in and prime away! Since shellac primer does give off a decent amount of fumes (more so than latex) it is important to keep the room ventilated by opening windows and turning a fan on. Some people also wear masks in order to have an added layer of protection against the fumes and chemicals.
Shellac primer is to be used only with oil paint or latex paint. The surfaces you can apply it to are highly versatile and include wood, metal, plaster, and plastic. Always keep the room you are working in heavily ventilated as it contains VOCs. When working with shellac primer and make sure to thin it out with alcohol. You can use both synthetic or natural bristle paint brushes with shellac primer, but most people prefer natural bristled brushes.
Q: How do I decide which primer to use?
A: This depends on the type of paint you will be using over the primer, as well as the surface you need to prime.
Q: What prep work should I do before I prime?
A: If you’re priming drywall, make sure to clean it with a wet cloth and gentle soap and let it dry. You should also repair any holes or cracks before you prime as well.
Q: What type of brush should I use?
A: This depends on the primer. If you’re using a latex primer, you can use synthetic brushes. With oil primer, the use of natural brushes is recommended.
Q: There is already paint on my walls, and I need to make sure I am using the right primer. How do I tell what kind of paint it is?
A: A simple trick to figuring out what type of paint is on your walls is to use a cotton ball saturated in alcohol. Wipe a section and look at the cotton. If paint comes off onto it, you are dealing with latex. If the cotton ball is clean, the paint is oil-based.
Q: How do I apply primer?
A: Primer is applied in the same way that paint is, but since you are painting over it it is a much quicker application process. Choose the right primer and the right brush and paint it on to whatever surface you are working with.
Q: Which primer is best for covering up stains?
A: For those priming and painting over heavily stained areas (such as walls coated with years of nicotine), oil-based and shellac primer is ideal.
Q: What will happen if I don’t use a primer?
A: Painting directly onto a surface (especially wood surfaces) cause the paint to soak into it. You’ll end up going over your surface again (and again, and again). You will also be dealing with peeling paint after your finished, which means you will need to redo your project again, with the added benefit of having to smooth out the paint left over. Always use a primer!
Q: What are VOCs?
A: VOCs are “Volatile Organic Compounds” and are found in many different paints and primers. This is one of the many reasons you cannot easily dispose of certain primers and why you should always paint in a well-ventilated room. Much attention has been drawn to VOCs in recent years, and, according to the EPA, they have the potential to cause health issues.
Q: How do I dispose of oil-based primer?
A: Let the paint dry out first (this can take a few days for a small amount or a few months for a large amount). You can place this curbside with the rest of your garbage, just make sure to keep the lid off of the can so the garbage men can see that it is dry before they take it.
Where to Buy
All of the primers listed in this article are readily available at any home improvement store (Home Depot, Lowes, etc.). There are many online purchase options available as well. If you have any confusion or need clarification, purchasing in a brick and mortar store is recommended, as associates can help to answer any further questions you may have. Each store should have all three types of primers.
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