Roe Paint Blog | Roe Paint

What Primer Do I Use?

Written by Jud Masters | Jul 3, 2025 3:15:00 PM

All that work prepping your surface, picking the perfect color, and you’re finally ready to paint–but there’s that nagging question, “Do I need primer?” quickly followed by “Is it necessary?” “What does it really matter in the end?” 

With so many primers out there (and paints with primer included), it’s easy to get overwhelmed and choose to skip priming altogether. 

But using the right primer in the right situation can be the difference between a paint job that lasts and one that starts peeling or bleeding through in months. 

At Roe Painting, we’ve been painting and priming walls for over 25 years. Whether it’s stained ceilings, glossy trim, or brand-new drywall, we know how and when to use primers to make sure your topcoat performs exactly the way it should. 

In this article, we’ll break down what the primer actually does and how to choose the right one for your surface. By the end, you’ll know exactly when primer is worth it (and when you can skip it).  

What Primer Actually Does and Why It Matters

Primer isn’t just an extra coat. It’s a purpose-built layer that helps paint do its job better. While different products have different features, almost all primers fall into one (or more) of these three roles:

  1. Blocking: Stops stains, odors, and discoloration from bleeding through your paint.
  2. Bonding: Helps paint stick to slick or previously finished surfaces. 
  3. Sealing: Creates an even surface so paint absorbs uniformly and finishes smoothly. 

Using the right primer can prevent peeling, patchiness, and uneven color, especially on surfaces like: 

  • Water-stained ceilings
  • Glossy trim or cabinets
  • New drywall
  • Raw wood or porous masonry

If your surface falls into any of these categories, skipping primer could mean redoing the entire job much sooner than you’d like. 

Blocking Primers 


Blocking primers are your first line of defense when something underneath the surface could show through your paint. That includes: 

  • Water stains
  • Smoke or nicotine damage
  • Pet odors or cooking smells
  • Rust marks of tannin bleed (from wood)

These primers seal in problem areas so they don’t bleed through, even if you’re using light-colored paint. 

When to Use

  • Covering over ceiling stains or damaged drywall
  • Painting over smoke-damaged walls or musty odors
  • Priming wood with heavy tannins (like redwood or cedar)

Product Tip:

  • Stronger smell=stronger block. Solvent-based products like Zinsser Cover Stain or BIN Shellac are powerful but intense.
  • For lighter-duty or low-odor projects, Kilz 2 Latex can work, but expect to add an extra coat or two as needed. 

Pro Tip: If you’re not sure how strong your primer needs to be, ask a pro or test a small area before painting the entire wall. 

 

Bonding Primers: For Slick or Hard-to-Paint Surfaces


If you’re painting over a surface that’s shiny, smooth, or previously finished, a bonding primer (also called a tie coat) helps your topcoat stick and stay stuck. 

Without one, paint might look fine at first, but may start peeling off in sheets. 

When to Use: 

  • Glossy or oil-based trim and doors
  • Prefinished metal (garage doors, gutters, flashing)
  • Tile, plastic, fiberglass, or other slick surfaces
  • Cabinets and laminate furniture

Bonding primers are designed to adhere to both the old surface and the new paint, which is why they’re critical when switching from oil-based to modern water-based paints. 

Product Tip: 

  • For light-duty jobs: Zinsser Bulls Eye 1-2-3 (good for most trim and indoor use)
  • For high-adhesion situations: XIM UMA (ideal for metal, plastic, or anything tough to grip) 


Pro Tip: If you can scratch your paint off with a fingernail, it wasn’t properly bonded.

Sealers: For New or Porous Surfaces? 


Sealers (sometimes called undercoaters) are used to create a uniform surface before painting. Without one, porous materials absorb paint unevenly, leaving you with a blotchy or dull finish. 

These primers soak into the surface and “seal it up,” so your paint can sit on top and dry evenly. 

When to Use: 

  • New drywall or patches (mud, texture, or joint compound) 
  • Raw wood (especially for fine finishes like trim or cabinets)
  • Masonry, stucco, concrete block, and tilt-up walls

Product Tip: 

  • Drywall: Use a PVA primer (like Glidden PVA or Valspar PVA)—affordable and made for the job
  • Wood: Go with a designated undercoated (oil-, shellac-, or lacquer-based for smoother sanding)
  • Masonry: Use a dedicated masonry or block filler primer to prevent blotching and over-absorption

Pro Tip: If your finish coat looks uneven, it’s often a sign that the surface wasn’t sealed properly.

What About Paint-and-Primer-in-One? 

You’ve probably seen paints labeled as “2-in-1” or “self-priming.” These products work well in specific situations, but they’re not a true replacement for a dedicated primer in every case. 

Good for: 

  • Repainting similar colors over clean, previously painted surfaces
  • Low-traffic walls in good condition
  • Quick refreshes where no stains, repairs, or bonding issues exist

Not enough for: 

  • Stain blocking (water, smoke, grease, etc.)
  • Raw or repaired drywall
  • Glossy surfaces or hard-to-paint materials
  • Drastic color changes (especially light over dark)

Bottom line: Paint-and-primer-in-one can save time, but only if the surface is already in great shape. When in doubt, a dedicated primer will always give you better long-term results.

When in Doubt, Prime it Out

Primer isn’t just an optional add-on in most cases. It’s a strategic first step that helps your paint perform better, look smoother, and last longer. 

When you skip it, you risk stains bleeding through, peeling paint, or a finish that looks uneven and unprofessional, often leading to a do-over that costs more time and money. 

Instead of thinking of primer as extra work, think of it as your paint’s insurance policy. Whether you need to block, bond, or seal, choosing the right primer up front protects the quality of everything that comes after. 

Not sure where to start? Let Roe Painting help. We’ll match the right products to your project and make sure your finish doesn’t just look great, it lasts. 

Wondering if the quality of your paint matters just as much as the primer? 

Check out our guide: Are Premium Paints Worth the Extra Cost? To see how choosing the right finish coat can save you time, money, and frustration in the long run.