Primer is a vital part of any painting project, and it can be confusing to know how long it will last. Primer is used to prepare the surface to be painted, and it acts as a base layer that helps the paint adhere properly and last longer. Primer can come in oil-based, latex, shellac, epoxy, urethane, and water-based forms.
Depending on the type of primer you use, the shelf life and how long it can sit before painting can vary, so it is essential to know the specifics of the primer you are using. When applying primer, it is vital to ensure the surface is clean and dry. Primer coats should be thin and multiple coats can be necessary for a good paint job.
The primer should dry completely before painting, as too many coats can cause a tacky primer. Shellac primers dry quickly and can last for a long time. Oil-based primers have a longer shelf life than latex primers but can take longer to dry. Urethane primers are suitable for uneven surfaces and can leave a high gloss sheen appearance.
Water-based primers are fast drying and good for previously painted and unpainted surfaces. In our guide, you can learn more about how long is primer good for before your paint job. By the end, you’ll also learn, does paint primer expires, and does primer go bad? (Read Drywall Vs Plaster)
What Is Primer?
Before painting, a thin layer of primer paint is applied to any surface. Filling in the cracks and gaps between the coats of paint protects the surface by making them less noticeable and providing a smooth surface for applying the subsequent layer of paint.
Primers are typically transparent, but they can be colored if preferred. They might also include dyes or pigments to help them stand out more against a gray wall or ceiling than a plain white primer would.
Different Primers and Drying Times
There are many types of primers for painting projects, such as water-based primers, urethane primers, shellac primers, oil-based primers, latex primers, epoxy primers, and acrylic lacquer primers.
The drying time for primers varies depending on the type of primer and how thick the coats are applied.
- Generally, water-based primers dry the quickest, typically within an hour or two.
- Oil-based primers may take up to 24 hours to completely dry.
- Urethane and epoxy primers may take even longer, up to several days.
- Shellac primers usually dry within 30 minutes.
- Acrylic lacquer and latex primers dry in 1-2 hours to dry before applying acrylic paint.
Oil-Based Primer
Oil-based primers are thicker than water-based primers because they contain more color (like white paint) and metal fillings. Oil-based primers typically cure in 24 hours. The paint will be dry to the touch in a few hours, but the priming will take longer to harden (cure). This primer takes longer to dry. Therefore few people use it.
To apply an oil-based primer, use a rolling brush or roller with a fine enough nap to avoid brush marks. You can also use a sponge roller. After rolling or brushing the primer once, wait 30 minutes before repeating. This gives the primer time to dry and prevents sags or runs in your paint finish. Once the first primer coat is dry, paint your wall. (Learn How Long Does Spray Paint Take To Dry On Plastic)
Latex Primer
Latex primer seals surfaces. It’s a water-based primer for dry walls, wood, masonry, and metal surfaces. It helps the paint cling to the surface and provides a smooth, even finish.
The best time to apply latex primer depends on the condition of your walls or woodwork before painting. If your walls and woodwork are in decent condition, apply latex primer after washing them with soap and water.
Urethane Primer
Urethane primers can be used in various locations, including metal and wood. Drying time varies by application method and temperature. Urethane primers dry in 24 hours at 70°F and can be utilized after 30 minutes.
Urethane primers will stick to most surfaces, including metal, plastic, and wood. They are perfect for furniture restoration, auto body repair, and staining cabinets and floors.
Shellac Primer
How long can primer sit on the shellac primer variety? It is an organic solvent that dries quickly, and you can paint after an hour, but we recommend waiting at least 2–3 hours or overnight to be sure it’s totally dry.
It’s best to sand between applications of shellac primer to remove imperfections and prepare the surface for paint. Shellac Primer dries quickly on walls, plaster, concrete block, metal, and wood. It is a primer for previously painted surfaces like latex or oil-based paints.
Does makeup primer go off?
Primers can last anywhere from six months to twenty-four months. Eyeshadow primer typically lasts between six and twelve months.
Can You Paint Without Primer?
No, you cannot paint without primer because a primer surface is essential for adhering the paint properly to the surface and ensuring that the paint job lasts. Primer also helps create a smooth surface for the paint and increases the longevity of the paint color.
Yet, you can skip the primer coat in a couple of scenarios.
1. Using the Same Color to Cover Over Old Paint
If you are retouching previously painted surfaces with the same color in the same shade, you can omit to prime.
2. Use a darker color or shade of oil paint to cover up old paint
If you are retouching a painted surface with a significantly darker color than the previous one, you can omit the priming.
3. When Using Self-Priming Paint
Regarding DIY painting, new paint types using paint and primer are all the rage to cover old paint in a single coat.
To allow painters to avoid the priming phase, manufacturers combined the advantages of paint and primer in a single product you can use on an uneven surface.
Factors That Affect the Primer’s Sit Time
Type of Primer:
The type of primer used will affect the time it needs to sit before painting.
Oil-based primers take longer to dry than water-based primers, while shellac primers have the fastest drying time.
Surface:
The type of primed surface can also affect the time the primer needs to sit.
Porous surfaces will absorb the primer more quickly, requiring less sit time. Smooth surfaces take longer to dry, so they need more time to sit before painting.
Coats:
The number of coats of primer used will also affect the sit time. Thin coats will dry more quickly than thick layers, so the primer will need less sitting time.
Applying too many coats can result in a tacky primer needing more dry time before painting. (Learn How Much Does A 5 Gallon Bucket Of Paint Weigh)
Temperature and Humidity:
The temperature and humidity of the environment can also affect the primer’s sit time.
Warmer, humid conditions will cause the primer to dry more quickly, while cooler temperatures and lower humidity will slow the drying process.
How Long Does Primer Take to Dry?
The drying time for primer can vary depending on the primer used.
Generally, oil-based primers take up to 24 hours to dry, while latex primers usually take 1 to 4 hours to dry. Shellac primers can be dry to the touch in as little as 20 minutes.
Do you always need to let a primer sit before painting?
You always need to let a primer sit before painting. The primer should be allowed to dry completely before any painting is done.
Depending on the primer type, it may take several hours to dry.
Latex primer dries quickly, while oil-based primers and shellac primers take longer to dry.
Remember, it’s vital to let primer sit before painting to ensure the paint adheres properly and makes up for any uneven surfaces.
How Many Coats of Primer Should You Use?
The number of coats of primer you should use depends on several factors, including the type of primer, the surface you are priming, and the final look you want to achieve.
For example, if you use an oil-based primer on a porous surface, you may need to apply a thicker coat to ensure proper adhesion.
If you use a latex primer on a previously painted surface, you may only need a thin coat before applying your latex paint.
Additionally, if you seek a high-gloss sheen appearance, you may need to apply two or more coats of primer. Ensure you read the instructions on the primer can determine the exact number of coats you should use.
Factors Influencing the Drying Time Of Primer?
The drying time of primer is influenced by various factors, such as the type of primer used, the surface being primed, the number of coats applied, temperature and humidity levels, and the primer’s shelf life.
Most primers have different drying times. For example, oil-based primers generally take longer to dry than latex or water-based primers, or you use one to prime unpainted surfaces rather than on old paint.
The surface being primed can also affect the drying time of the primer. Porous surfaces, such as wood, will absorb more primer and take longer to dry than a non-porous surface, such as metal.
The number of coats of primer applied can also affect the drying time. Multiple thin coats of primer will take longer to dry than a single thick coat.
Temperature and humidity levels can also affect how long you leave primers unpainted. Warmer temperatures make primer dry faster, and higher humidity levels will cause the primer to take longer to dry.
Finally, the shelf life of the primer can make primer dry faster or slower, especially if you have already opened the can. An older primer that has exceeded its shelf life may take longer to dry than a fresh primer.
Note: Using primer with a spray gun offers fast drying primer out of all application methods.
What Happens If You Paint Over Scratched or Ruined Primer?
If you paint over a scratched glossy surface or ruined primer, the paint will not adhere correctly or provide the desired high gloss sheen appearance. The primer should be sanded down, and a new layer should be applied. The primer should then be given time to dry completely before applying any coats of paint.
Applying an oil-based primer, such as an oil-based primer, urethane primer, or epoxy primer, can help the paint adhere better and provide a smoother surface for the paint to adhere to.
If a filler primer is needed before the new primer, it should be applied and allowed to dry before the primer and your oil-based paints are used. How long can primer sit? Before painting, it needs the recommended time and should be applied to the primed surface in thin coats. Once the primer is dry, the paint can be applied in two coats, with thinner coats providing better coverage. (Read Painting Satin Over Semi-Gloss)
Does unopened paint primer expire?
No, unopened paint primer does not expire. Primer has a shelf life when a product can be stored before it degrades.
The shelf life of primer can vary depending on the type of primer, but typically primer can last for several years if stored correctly.
The primer adheres properly to surfaces and provides a smooth surface for painting projects.
It also helps to create a high gloss sheen appearance and has a longer lifespan than other types of paint.
The primer should be stored in a cool, dry place, away from direct sunlight and extreme temperatures.
It should also be kept away from moisture and humidity. If the primer is stored correctly, it should have a long shelf life and will not expire.
Can Latex Paint Go Bad?
Yes, latex paint can go bad. Latex paints are water-based and have a shelf life of up to 10 years if stored properly.
If the paint has been exposed to extreme temperatures, has had its lid removed, or has been left open, it can become dry and unusable. The paint should be inspected for any signs of drying, cracking, or separation before use.
If the paint is bad, it should be appropriately disposed of and replaced with a new container of latex paint.
Can Oil-Based Paint Go Bad?
Yes, oil-based paint can go bad. If the paint has been sitting around for an extended period, it can start to break down and separate.
Oil-based paints start deteriorating if the paint is left in a warm environment or exposed to extreme temperatures.
If the oil-based paint sits around too long, it will become thick and difficult to apply. This could cause the paint to not adhere properly to the surface, potentially leaving a bad paint job.
