How to Cull and Use Primer

Solve mutual paint coverage problems with these expert tips for choosing and using primer

Introduction

Painting pros recommend the all-time primers to solve common painting problems, including stains on walls, moisture impairment, one-time painted surfaces, odors, color changes and new exterior wood.

One of the most powerful tools in whatsoever pro painter'southward arsenal is what goes underneath the paint — primer. Primer is an excellent trouble-solver that's less like pigment and more like glue. It sticks to whatever you're preparing to paint and turns information technology into a smooth, uniform surface that'southward ready for paint.

But if you've e'er walked downward the primer aisle at a abode center, y'all know the primer choices are mind-extraordinary. To cut through the clutter, we asked iii professional painters, each with twenty-plus years of experience, to give us their recommendations for the best primers to use for common painting challenges. Their experience volition assist you choose the best primer for the task, and then your paint will look better and last longer.

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Project stride-past-stride (11)

Step 1

Trouble 1: Interior stains and odors

Some stains will bleed right through most primers and paints no matter how many coats you apply. The same goes for astringent odors like smoke from fires and cigarettes. The solution is stain-blocking primer, which is available in oil-based (alkyd) and water-based (acrylic-latex) versions.

  • Oil-based versions give off a nasty smell and require paint thinner for cleanup, but they're more reliable for blocking water-based odors and stains like rust, nicotine, smoke, forest tannins and, of form, water (see "Shellac: The Original Primer," below, for dealing with severe stains and odors).
  • Water-based stain-blocking primers offer easy cleanup and less odor and come in low- and no-VOC (volatile organic compounds) formulations. These piece of work all-time to block solvent-based stains like crayon, grease, ink and scuff marks.
  • Both versions are white, so information technology's a proficient thought to tint them gray or close to your topcoat color if they'll exist covered by dark-colored stain block paint.

Kilz and Benjamin Moore paint cans

Do I Always Need to Prime Earlier Painting?

You don't have to prime previously painted surfaces if the pigment is in skillful shape—no chipping or peeling. Interior walls usually don't demand priming except in the instance of stains, repairs or a paint colour that's drastically different. Interior painted woodwork commonly needs spot priming with wood primer at a minimum. Exterior pigment takes such a beating that it almost e'er needs priming with an exterior paint primer.

Step ii

Problem two: New Drywall

The mud used on the seams of drywall absorbs paint differently than the rest of the drywall. This difference in porosity can cause blotchy, dull areas under the paint (a problem called "flashing") and an inconsistent sheen. Prevent this trouble by using a drywall primer-sealer.

  • If yous're an ace drywall finisher and your walls are perfectly smooth, you can utilise a standard drywall primer-sealer. But if you're like most of the states, your finished drywall probably has some tiny pockmarks, fine ridges and scuffed paper from sanding. The solution to those minor imperfections is a "high-build" drywall primer-sealer. This heavier-bodied primer-sealer is a footling more expensive than standard primer-sealer, but it does a amend chore of leveling and filling in rough or uneven drywall construction. (Sorry to say that not even a high-build drywall primer can hibernate a terrible tape chore.)
  • Alternatively, if your drywall is relatively smooth and the topcoat is going to exist a flat pigment, you tin skip the primer and use two coats of high-quality self-priming water-based flat paint (see "Cocky-Priming Paints," beneath). The heavy-bodied paint resins in self-priming paints seal the surface and make full imperfections (which are less visible in apartment pigment anyway).
    • Pro tip: Paint within 48 hours of priming. Many primers are formulated to physically and chemically bail with the paint practical over them. One time you've primed, yous should paint over it within a couple of days or information technology volition lose its effectiveness and you lot'll need to prime again.

Step 3

Trouble iii: Moisture-Decumbent Areas

The loftier moisture in areas such as kitchens, closets, bathrooms and laundry rooms can cause paints to mildew, scrap or peel. Interior moisture moving outward through the wall tin can cause peeling, bubbles or baking on exterior walls as well.

  • Apply a vapor barrier primer to seal the surface and minimize the passage of moisture through the walls to the outside.
  • If mildew is a serious business, apply a stain-blocking primer to forbid mildew and peeling on interior walls and baking on outside walls.
    • Pro tip:Make certain to kill any mildew with a ane-role bleach and three-parts water mixture before priming.
  • Then use a topcoat that specifically resists mildew (bank check the characterization).

Painting wall

Step 4

Problem 4: Repaired Walls

Like new drywall mud, wall patches absorb pigment differently than the rest of the wall (see photo below).

  • A drywall primer-sealer seals the porous surface and then pigment won't sink in and look dull or blotchy.
  • To prevent flashing, cover everything, whether it's dabs of spackle or broad patches of joint compound, with a practiced-quality drywall primer-sealer.
  • If yous have plaster rather than drywall, whatsoever repairs you make will need a glaze of oil-based stain-blocking primer.
    • Note: Without it, lime stains volition form around the repairs and volition bleed through the topcoat. This applies to tiny caulking and spackling bear upon-ups equally well equally major repairs with articulation compound.

Damaged wall paint Repairing wall paint

Step v

Trouble 5: New Interior Bare Wood

  • Prime bare wood with wood primer to seal the thirsty surface, hide imperfections and bind the wood fibers to brand the surface more than compatible.
    • Pro tip: Slower-drying oil-based primers, such every bit an enamel undercoat primer, provide meliorate adhesion and are easier to sand than water-based primers. W ater-based primer is probable to raise the grain of the woods and require more sanding earlier you apply the topcoat.

Step 6

Trouble 6: MDF (Medium-Density Fiberboard)

  • Unless the MDF comes pre-primed, use an oil-based primer.
    • Pro tip: Don't apply a water-based primer, which tin soak into the surface and cause it to smashing.
  • Earlier priming, sand the surface smoothen and make sure information technology's dust-gratis.
  • Prime all surfaces, including the board edges.

mdf core plywood

Shellac: The Original Primer

Shellac has been used for centuries and is even so the best primer for a few situations. It'south an first-class choice if you need a fast-drying spot primer to foreclose wood knots, rusty nail heads and the most severe water-based stains and odors such every bit smoke, soot, urine and nicotine from-bleeding through the topcoat. Shellac (a common brand is BIN) can soften in straight sunlight and by itself isn't durable enough for exterior use. If yous use it for exterior spot priming, prime number over it with a water-based exterior primer before applying the topcoat. Shellac requires denatured alcohol for thinning and cleanup. For the best results, make sure the surface is completely clean and dust-free before applying. The photo shows spot-priming nail heads and knots with shellac to prevent rust and wood resins from bleeding through the topcoat.

Step seven

Problem seven: Previously Painted Interior Woodwork

    • Note: If the old pigment is in skilful shape, there's no need to prime.
  • If the pigment is chalking or is chipped, utilise an oil-based enamel undercoat primer after properly prepping the surface.
    • Pro tip: An enamel undercoat primer bonds well to previously painted surfaces and improves the topcoat by flowing out to a dense, smoothen uniform foundation without laps or brush marks. Fast-drying primers similar shellac and many water-based products dry likewise quickly and become breakable. This can cause lap marks and makes it harder to sand and get a smooth base for the topcoat. Oil-based primers sand well but dry more slowly (some tin can have 48 hours or longer).
  • If you want to use a water-based production, look for a high-build acrylic-latex enamel undercoat that's specifically designed to be sanded.
  • For quicker priming, employ a roller on the door and a ii-inch brush on interior trim such as casings, base of operations and doorjambs.
  • For a shine paint job, sand lightly subsequently the primer dries.

Painting a door

Step 8

Problem 8: Drastic Paint Color Change

When you alter from a light color to dark or vice versa, it can take many coats of pigment to hide the existing paint color.

  • Tint your primer gray or a color similar to your finish pigment to reduce the number of topcoats y'all need to utilise to get skilful results.
    • Pro tip: Not all primers can be tinted darker colors, and then brand sure to choose 1 that can.
    • Note: Fifty-fifty without a desperate color change, tinting your primer gray volition assistance enhance the color of most dark-colored interior paints and better a primer'southward "hibernate" (how well it covers the imperfections and colour of your wall surface).

Deep Tint can

Step 9

Problem ix: Exterior Wood

Outside paint takes a beating. And 1 of the best means to extend the life of your paint job is with a adept primer. And then unless yous enjoy scraping paint, spend about $30 per gallon on a height-quality acrylic/latex exterior primer.

  • Look for "100 percent acrylic" on the label, and make sure the forest surface is clean, dry and deadening (no sheen).
    • Note: On properly prepared walls, a loftier-quality primer tin double the life of your outside paint chore.
    • Pro tip: Use a primer and paint from the same manufacturer. Many primers are formulated to work best with sure paints.

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Stride 10

Trouble 10: Onetime Exterior Paint

If exterior paint is in great shape, there's no need to prime. But that'south inappreciably ever the case. At the very least, you'll have to spot-prime number whatever blank woods where the paint has peeled abroad.

  • Use a high-quality acrylic/latex outside paint primer.
  • If the paint is "chalking," you'll have to prime the entire surface.
    • Pro tip: To detect chalking, just wipe the paint with a rag. If the rag picks up colored dust, you've got chalking.
  • Before you prime, pressure-wash the siding to remove loose paint and congenital-up grime and amend paint adhesion.
    • Pro tip: Keep the nozzle at least 16 inches away from the woods.
  • Make clean, scrape and sand and areas that are peeling or that take clay and mildew.
    • Pro tip: Training is the primal to a long-lasting exterior paint job. If information technology's not done correctly, the surface will pare again within a year or two.

Washing house

Step eleven

Problem 11: Exterior Woods that Stain

Cedar, redwood and a few less common woods comprise lots of pigments, called tannins, that will bleed through standard primer and pigment.

  • To stop the bleeding, apply an outside oil-based primer and stain-blocking exterior paint primer for larger areas and top with an acrylic/latex finish coat.
    • Pro tip: If you're going to use an oil topcoat, use only an oil-based primer.
    • Pro tip: Thank you to new water-based primer paint formulations, you tin pigment an acrylic/latex topcoat over either an oil-based primer or water-based primer.

Wood Primer can

Originally Published: Dec 26, 2020