Spray paint is easy to apply, dries in time, and offers a good finish quality. But, how many coats of spray paint do you need?
For proper coverage and protection, you need 2-4 coats of spray paint. However, the number of coats depends on the paint type, surface type, and thickness of the coats.
Also, you must only apply thin coats and wait 1 hour for each coat to dry before applying a new one.
Why Does The Number of Coats Matter?
The number of coats determines the finish’s quality and the spray paint drying time. So, you must apply thin coats so the finish can dry evenly and faster.
If you apply multiple thick coats, the finish will take longer to dry. For each extra coat you apply after the third one, the paint will take 2 more hours to dry.
Besides affecting the dry time, the number of coats also determines the color shade. The more coats of you apply, the darker the color finish will get. That’s because more coats mean more paint pigments (or color) on the surface. The increased levels of pigments will deepen its color.
It also determines the level of protection. For example, rust-oleum spray paint is designed to protect the metal from rust, but you need the right number of coats to get rust protection.
If you apply less than the required number of it, the finish won’t protect the metal. On the other hand, if you use more than the needed coats, the finish turns sticky.
When To Apply an Extra Coat Of Spray Paint?
Inspect the color of the previous coating after it dries. If the previous coating looks lighter than you wanted, apply another coat.
For instance, if you want a green finish, but you get a light-green finish, you must apply another coat to archive a deeper finish. For every coat you apply, the color shade of the finish gets deeper.
You must also apply another coat if you want bleed-through from the existing finish. In this case, an extra coat is needed to seal and cover the existing color.
You can also check the manufacturer’s instructions on the spray paint bottle to know if you need another coat. Manufacturers often include the number of coats needed for different surfaces.
Don’t Apply Too Many Coats
More than 5 coats of spray paint are too much because the finish will get ruined. You only need 3-4 thin coats to get a good finish. If you apply too many coats on a vertical surface (such as walls or fences), the paint will drip and run off the surface.
Since there is too much spray paint on the vertical surface and nothing for it to stick to, the paint will drip off the surface and create a long sticky finish. Also, when the sticky finish dries, it will be riddled with lines, bumps, and blemishes, and the finish might crack.
Too many coats on a horizontal surface (such as a tabletop), also means the finish will take longer to dry and might turn sticky. When spray paint turns sticky, the finish will attract filth and start smelling.
The worst thing about having a bad finish is that you must fix it afterward. So, instead of enjoying it, you must spend extra hours whipping off the excess spray and sanding the finish. Sometimes, you must remove the entire finish and re-apply it. So, whatever you do, don’t overapply it.
Don’t Apply Less Than 2 Coats
If you don’t apply enough coats of spray paint, the finish will be weak and won’t protect the surface underneath. You will also get a light color shade finish because there will be fewer pigments on the surface.
The minimum amount for spray paint is 2 coats. That’s because spray paint coating is thin, and you need at least 2 coats for proper coverage and durability. Most of the time, 4 coats are enough.
The finish will be thin and can be dented and damaged easily if you don’t apply enough coats. In addition, a thin coat won’t protect the surface underneath from damage or water. With fewer coats, the color shade will be lighter, and the paint underneath will bleed through.
Spray Paint Dry Time Between Coats
It takes spray paint 1-4 hours to dry enough for a re-coat. This gives each coat enough time to harden so it can support the next one. Oil-based spray paint takes longer to dry since it uses oil as its solvent, and oil takes longer to evaporate.
You must wait 2 hours after the third coat of spray paint. That’s because the more coats of apply, the longer it takes it to dry.
To know if the spray paint is dry enough for a re-coat, use the sandpaper method. Wipe ultra-fine sandpaper across the finish; if the sandpaper gets clogged, the finish isn’t dry enough. If the paint doesn’t get into the sandpaper and the finish looks textured, the finish is dry enough.
Number of Coats For Different Surfaces
You need at least 2 coats of spray paint on the metal. That’s because metal surfaces need protection from air and moisture to prevent rust. If the metal surface isn’t coated with enough spray paint, it will be exposed to air and moisture, which causes rust.
However, if you use Rust-Oleum spray paint, you need only 1 coat of it. This spray paint is thick and formulated with chemicals and additives that protect the metal.
The number of coats for metal also depends on the condition of the metal surface. For instance, if the metal surface is defective and you want to cover the damaged spots, you need more coats to fully cover those spots. You can also check the manufacturer’s instructions to know for sure.
For plastic, you need 1 coat of spray paint. However, if you want a deep-colored finish, you can apply 2 coats.
You shouldn’t apply more than 2 coats because plastic isn’t porous, so the coating won’t stick properly. If you apply too many coats, the paint won’t stick and will drip off the surface. To help it stick to plastic, you must sand and prime the surface first.
For a normal finish, you must apply 2 coats of spray paint to the wood. For a deeper finish, you can apply 3 coats. However, if the wood has an existing color that you want to cover, you must apply 3 coats to prevent bleed-through.
If the wood is primed or sanded, you don’t need too much of it because the finish can become too thick.
On furniture surfaces, you need 2-3 coats of spray paint. You must apply more for high-traffic furniture to protect them from damage and scratches. However, for decorative furniture, you don’t need too many, 1 is enough.
You need 3-4 coats of spray paint on a car. You need more coats on cars because they see a lot of friction.
Frequent washing, stains, dust, UV rays, heat, rain, and dents can remove the spray paint from the car. So, you need enough of it to handle all of these without chipping prematurely.
However, you must only use automotive spray paint on cars, and you must apply primer first.
The minimum number of spray paint coats is 2, while the maximum is 4. If you apply less than 2 the finish will be weak and won’t protect (or cover) the surface underneath. If you apply more than 4 coats, the finish will take longer to dry and turn sticky.