How can I get primer to stick to glossy or dirty walls before painting?

Short answer

To get primer to stick to glossy or dirty walls, clean thoroughly to remove dust/grease, dull the sheen with sanding or a liquid deglosser, then apply a quality bonding primer designed for slick surfaces. Let it cure fully before topcoating.

Why this works

Glossy paint and contamination (grease, smoke residue, soap scum) prevent primers from mechanically and chemically grabbing the surface. Cleaning removes contaminants; deglossing creates micro-scratches for grip; bonding primers use resins that adhere to slick finishes and lock down any residual staining.

What you’ll need

• Cleaning:
  • Vacuum with brush attachment, microfiber cloths
  • Degreaser (Krud Kutter Original, Dawn + warm water) or TSP substitute
  • Mildew remover (EPA-registered) or a bleach solution for small mildew spots
  • Clean water and buckets/sponges
• Surface prep:
  • Sandpaper: 120–150 grit to break gloss, 180–220 grit to smooth
  • Sanding pole or random-orbit sander with dust extraction (optional but faster)
  • Liquid deglosser (“liquid sandpaper”) as an alternative to sanding
  • Spackle, putty knife, acrylic latex caulk (paintable)
• Primers (choose based on conditions):
  • Bonding: INSL-X STIX, KILZ Adhesion, Zinsser 1-2-3 (for light-to-moderate gloss)
  • Heavy stain/odor: Zinsser BIN (shellac) for smoke/nicotine/marker, or oil-based stain-blocker
• Application:
  • 2–2.5 in angled brush, 3/8 in woven roller cover (smooth walls), tray, extension pole
  • Painter’s tape, drop cloths
• Safety:
  • N95 or P100 respirator for sanding, chemical-resistant gloves, goggles, good ventilation

Step-by-step

1. Protect the area

   • Move furniture, cover with drop cloths, tape off trim and fixtures. Turn off HVAC or cover returns to limit dust spread.

2. Identify the existing finish

   • If the wall is very glossy or likely oil-based (common in older trim/kitchens), plan for a bonding or shellac primer. A quick test: rub a hidden spot with denatured alcohol on a rag. If paint softens, it’s latex; if not, it may be oil-based.

3. Dry clean first

   • Vacuum walls with a brush head, then wipe with a dry microfiber cloth. This keeps grime from smearing during wet cleaning.

4. Wash the walls

   • Kitchens/grease: Use a degreaser or TSP substitute. Bathrooms/soap scum: Use a bathroom cleaner or TSP substitute. Nicotine/smoke: Degrease thoroughly, then plan on a shellac primer. Rinse with clean water and let dry.
   • Mildew: Treat with an EPA-registered mildew remover. For small areas, you can use a mild bleach mix (see specs below). Rinse and dry completely.

5. De-gloss the surface

   • Sand: Scuff with 120–150 grit to break the sheen, then smooth with 180–220 grit. Feather any edges around patched spots. Vacuum and wipe with a slightly damp cloth (avoid tack cloths with water-based paints; they can leave residue).
   • Or deglosser: Apply per label with a lint-free cloth, working in sections. Let it flash off as directed before priming.

6. Patch and caulk

   • Fill holes with spackle, sand flush (180–220 grit). Caulk gaps with paintable acrylic latex (avoid 100% silicone; paint won’t stick to it). Let dry.

7. Prime correctly

   • Choose the right primer:
     • Slick but clean walls: A bonding acrylic like INSL-X STIX or KILZ Adhesion.
     • Stains/odors (smoke, water marks, marker): Zinsser BIN (shellac) or an oil-based stain blocker.
   • Apply one even coat, maintaining a wet edge. On very glossy or previously oil-based finishes, a second coat may improve adhesion and hide.
   • Respect dry and cure times before topcoating.

8. Verify adhesion (optional but smart)

   • After primer cures, do a crosshatch tape test: lightly score a small # pattern with a utility knife, press on quality painter’s tape, then pull sharply. Minimal to no primer should lift if adhesion is good.

Quick specs
- Sanding: 120–150 grit (degloss), finish 180–220 grit
- Bleach mix for small mildew spots: 1 cup household bleach to 3 cups water; never mix with ammonia or acids
- Dry time (typical):
  - Bonding acrylic primer: dry to touch 1–2 hrs, recoat 3–6 hrs
  - Shellac primer: dry to touch ~15–45 min, recoat 45–60 min
- Coverage: 250–400 sq ft/gal (varies by product and surface)

Safety notes

• Ventilate well, especially with shellac primer (uses denatured alcohol). Wear gloves and eye protection during cleaning and deglossing. Use an N95/P100 when sanding. Do not mix cleaning chemicals. If the home was built before 1978, assume possible lead paint—avoid dry sanding; consider RRP-safe methods or hire a lead-safe certified pro.

Tips for best results

• Work top-down: ceilings, then walls, then trim. Grease and dust fall as you clean.
• Temperature and humidity matter. Stay within primer label ranges to avoid adhesion and cure issues.
• Use quality roller covers; cheap linting covers can contaminate the surface and reduce adhesion.
• For glossy trim or cabinets, bonding primer + light sanding between coats gives a tougher finish.
• If odor or stains persist after one coat of shellac primer, apply a second coat before painting.

Common mistakes

• Skipping the rinse after TSP/degreaser—leftover residue can repel primer.
• “Feather-touch” sanding that doesn’t actually break the sheen. You should see a uniform dullness.
• Using standard latex primer on hard, glossy oil enamel—leads to easy peel with tape or nicks.
• Priming over silicone caulk or waxy furniture polishes—paint won’t stick; remove and replace/clean thoroughly.
• Rushing cure time. Dry to touch is not fully cured; follow the label.

Cost and time

• Materials: Degreaser/TSP substitute ($8–12), deglosser ($10–15), sandpaper ($5–10), bonding primer ($30–60/gal), shellac primer ($45–70/gal).
• Time: A typical 12×12 room takes 2–4 hours to clean and degloss, plus 1–2 hours to prime (excluding dry time).

When to call a pro

• Heavy nicotine/smoke remediation throughout a home.
• Suspected lead-based paint requiring safe containment and cleanup.
• Persistent moisture or mold problems—fix the source before painting.
• High-gloss kitchen/bath enamel where a flawless finish is required and you lack sanding/finishing tools.

Follow the prep-clean-degloss-prime sequence and use a true bonding or stain-blocking primer where needed. Done right, the topcoat will lay down smoothly and stay put.