Before you can put paint over a surface, you must have applied enough coats of primer first to allow the paint to sit nicely. So how many coats of primer do you need?
You’ll need between one and 3 coats of primer on a surface before you can paint over it. On average, most manufacturers advise applying 2 coats of primer before the top coat is applied.
However, the number of coats required depends on the type of surface, the color of the paint, and the primer brand. So why does the number of coats matter for primer? Let’s find out.
Why Does The Number Of Coats Matter For Primer?
The number of coats matters for paint primer because the primer coating is designed to seal, protect, and provide a smooth undercoat for the top coat to sit on.
If you add too many coats of primer, the primer coating will become too thick. This will affect its dry time as the primer will take longer to dry. Also, too many coats mean that the primer will not dry evenly. Some parts of the primer coating will remain sticky while other parts can have varying colors.
The primer coating will be prone to hairline cracks, bubble formation, and it will eventually fall off the surface because it was laid too thick. Regardless of the surface or type of paint, too many coats of paint primer will ruin the finish.
The number of coats also matters for primer because fewer primer coats than required means that the primer coating will not seal the surface properly. If the surface is riddled with holes and cracks, you’ll need enough primer coats to seal these holes. If you apply fewer coats of primer, the holes and cracks will suck the paint when applied.
Asides from that, fewer than required coats of primer means that the primer coating will be prone to bleed through. Primers are designed to block stains on the surface from affecting the finish. If you apply fewer coats, the primer will not block the stains properly meaning that moisture, grease, and oils on the surface can affect the color and quality of the finish.
However, you should know that in some cases, you can get away with applying less coats of primer. For instance, if you are painting over a smooth and non-porous surface, one coat of primer is enough but how do you know if you need a second coat of primer? Let’s find out.
How Do I Know if I Need a Second Coat of Primer?
The best way to know if you need a second coat of primer is to check the instructions on the primer container. The number of required coats will be indicated on the container or user’s guide.
You can also know if you need a second coat of primer by inspecting the primer coating when it has dried. After it gets dry, if the primer coating is rough, heavily colored, or porous, then you need another coat.
Here are some cases where you’ll surely need a second coat of primer:
When Painting Over A Moist, Stained, Or Filthy Surface
When you are painting over a surface that is wet, stained, or filthy, you’ll need at least two coats of primer to properly block the moisture and stains from affecting the finish.
When Painting Over A Dark or Bright Color
When you are painting over a dark color like black or brown, you’ll need a second and possibly third coat of primer to cover the dark color. This is because dark colors are usually deep and very difficult to cover with just one coat of primer.
When you are painting over a bright color like green, red, or orange, you’ll need at least two coats of primer because these colors can easily bleed through one coat of primer.
Tip: To cover dark paints, use a grey primer.
When You Are Painting Over A Porous Surface
When painting over a porous surface, you’ll need a second coat of primer. This is because porous surfaces need to be properly sealed to prevent the paint from being sucked into the surface. Materials like wood and plaster are porous so you’ll need a second coat.
When Painting Over A Repaired Surface
If you are painting over a surface that has just been repaired, you’ll need a second coat of primer to seal imperfections and holes in the surface.
Also, it’s common to use concrete paste, caulk, polish, wood filler, and the likes on surfaces while repairing them. These compounds contain chemicals that can bleed through and affect the finish. So you surely need more than one coat of primer.
When Painting Over Old or Fresh Wood
Old wood or furniture will most likely be affected by pests like termites and bugs. These pests would have damaged the wood by biting and drilling holes in the wood. So you’ll need at least two coats of primer.
If you are painting over fresh wood, you’ll surely need more than one coat of primer. This is because fresh wood is usually very porous meaning that it would suck paint.
Asides from that, fresh wood usually contains tannins and oils that can bleed through and affect the finish. So you need at least two to three coats of a stain-blocking and moisture resistant primer. I recommend a shellac-based primer.
How Many Coats Of Primer Based On The Color?
You need one to two coats of primer when painting over a light color like white or ash. This is because light colors are not heavily pigmented so it’s easier to cover the color with just one coat of primer. Also, light colors are usually neutral which means they won’t affect the color of the paint.
In most cases, you only need one coat of primer on light color before painting over it. You should know that if the surface is defective, you’ll need more than one coat of primer on it regardless of the color.
If you are painting over a dark or heavily pigmented color, you’ll two to three coats of primer. This is because dark colors are usually deep and they contain more paint pigments than light paints. As such, it’s more difficult to cover the color or prevent it from bleeding through the finish.
You should know that if the surface is defective, moist, or stained, you’ll need to repair it first before applying the primer. Without doing that, you’ll need many coats of primer to first seal the imperfections on the surface and then more coats to cover the dark paint. This will cause you to apply too many coats of paint primer and ruin the finish.
If you are painting over a bright or vibrant color like red, yellow, or orange, you’ll need at least 2 coats of primer. This is because these paints contain a high volume of paint colorants which produces the bright color. So you’ll need more coats of primer to cover and prevent the bright color from showing underneath the finish.
If you are painting over a surface with the same color and shade of paint, all you need is one coat of primer provided the surface is smooth.
Related Read: What Primer Color Should You Use?
How Many Coats Of Primer Do You Need For Different Surfaces?
Let’s check some different surfaces:
On wood, you need at least 2 coats of primer. This is because wood is usually porous meaning that paint can easily be sucked in. So you’ll need at least two coats to properly seal the wood.
On damaged wood, you’ll need up to 3 coats of primer. This is because the wood will be riddled with cracks, holes, and stains that would all need to be covered and sealed with enough primer coats.
On wood trim like baseboards, you’ll also need 2 coats of primer because wood trims are usually closer to filth and the ground which means the wood trim will need enough protection.
On fresh and bare wood, you’ll need two coats of a stain-blocking or oil-based primer.
On drywall, you’ll need at least two coats of primer.
This is because drywall is a porous surface and the first coat of primer will most likely be sucked in by the drywall. So you’ll need a second coat. For fresh drywall, you might need more than two coats especially if the drywall is wet.
On outdoor metal, you’ll need two coats of spray primer since the metal surface will be exposed to the elements.
The two coats are to prevent oxidization on the metal surface which can cause rust. If the metal is indoor and shielded from the elements, you only need one coat of primer. If the metal already contains compounds that prevent oxidization, you don’t need a primer on the metal.
You need two coats of thick primer on kitchen cabinets. This is because kitchen cabinets are usually exposed to moisture, steam, heat, and constant friction or handling.
All of this can ruin the wood so it needs enough protection. Two coats of a thick or oil-based primer and two coats of wood stain are usually enough.
On MDF and other furniture, you can apply just one coat of primer. This is because these items are usually placed indoors which means the surface is shielded from the elements.
Also, MDF is not heavily used so it doesn’t need much protection. However, if the MDF is to be placed outdoors, you should apply two coats of primer.
On concrete, you’ll need two coats of epoxy primer. This is because stone surfaces like concrete and masonry are usually rough and uneven.
So you need enough primer coats to cover the concrete and create a smooth undercoat for the paint to sit on. If you are painting over a bright or dark color on the concrete, you’ll need a stain-blocking primer or three coats of regular primer.
You’ll need a coat of primer on plastic. This is because plastic surfaces are non-porous meaning that paint can’t be sucked in. Also, plastic is a very smooth material meaning that the finish will come out smooth even without a primer.
The purpose of applying primer on plastic is to give the paint something to bite into. Since plastic is non-porous and slick, paint doesn’t stick to it very well. However, with one coat of paint primer, the paint or top coat will have something to bite into. This will strengthen paint adhesion.
Overall, the amount of primer coats required depends largely on the surface to be painted, the type of primer, and the type of finish you want. If the surface is defective, apply two to three coats of primer.
If you are painting over a light or dark paint, you should use two coats of primer. If you aren’t sure how many coats you need, check the primer container for the manufacture’s instructions or contact a professional painter.