Painting door trims may look like a small job, but it has a big impact on the overall finish of your home. Whether you live in a humid coastal region like Brisbane or Wollongong, or a drier inland area such as Canberra or Alice Springs, understanding the right techniques—and how weather affects the job—makes all the difference. The following guide walks you through the entire process step by step, while also addressing variations between different door and trim types, and offering weather-related considerations relevant across Australia.
1. Understanding Door Trim Types
Before starting, it helps to understand the types of door trims commonly found in Australian homes:
MDF Trims: Common in modern homes. They have a smooth surface but are sensitive to moisture and require sealing and proper priming.
Pine or Hardwood Trims: Found in many homes. They may have knots, grains, and natural imperfections needing extra prep.
Metal Door Frames: Usually steel, common in units and commercial buildings. These require a specialised etch primer for adhesion.
Exterior Door Trims: Exposed to weather, UV, and moisture. They need durable, weather-resistant paint and careful timing around humidity and rain.
2. Tools and Materials You’ll Need
Sugar soap or mild detergent
120–180 grit sandpaper for prep
220–240 grit sandpaper for smoothing
Timber filler or gap filler
Painter’s tape
Drop sheets
Primer suited to trim material
Acrylic or enamel paint
Angled sash brush (38–50 mm)
Sanding block
Putty knife
Damp lint-free cloth
3. Preparing the Trim
Preparation is the key to a clean, long-lasting finish.
Clean the Surface:
Use sugar soap to remove grease, dust, and oils. Rinse and let dry thoroughly. In humid regions such as the Top End or Far North Queensland, make sure surfaces dry completely to avoid bubbling and peeling.
Light Sanding:
Use 120–180 grit sandpaper to remove gloss and help the new paint adhere. MDF needs lighter sanding, while hardwood trims may need more pressure. Wipe away dust with a damp cloth.
Fill Gaps and Imperfections:
Use filler to repair dents, nail holes, and cracks. Apply thin layers and allow proper drying time. Humidity slows curing, so expect longer wait times in coastal areas. Sand the filled areas with 220–240 grit until smooth.
Masking:
Use painter’s tape to protect walls, hinges, and handles. Press the tape down firmly to avoid bleed-through, especially in warm weather when paint tends to thin out.
4. Priming the Trim
Primer ensures adhesion and a smooth finish.
For MDF, use a stain-blocking or shellac-based primer. MDF absorbs moisture easily, so avoid unsuitable water-based primers.
For timber, use acrylic or oil-based primer depending on your topcoat.
For metal trims, an etch primer is essential to prevent rust and to help paint grip the surface.
Apply primer with a small angled brush, following the length of the trim. Allow it to dry fully; humidity can double drying times. Lightly sand the primer coat for a smooth result before painting.
5. Painting the Trim
Choosing the right paint is crucial:
Acrylic (water-based) paints dry faster, have low odour, and resist yellowing—ideal for interiors.
Enamel (oil-based) paints create a harder, more durable finish but take longer to dry, especially in humid environments.
For exterior trims, always choose a UV- and moisture-resistant formulation.
First Coat:
Load your angled brush lightly and use long, smooth strokes. Work in sections to avoid visible overlap marks.
Drying Time:
Follow the manufacturer’s instructions. In cities like Darwin or Cairns, dry times may be significantly longer because of humidity. Avoid painting exterior trims if rain is forecast.
Sand Between Coats:
Once dry, lightly sand with 240 grit sandpaper to ensure a flawless second coat.
Second Coat:
Apply smoothly and evenly. Two coats are usually enough, though older timber or high-gloss surfaces may need a third.
Remove painter’s tape only after the paint is fully dry to avoid tearing the finish.
6. Tips Based on Australian Weather Conditions
Humidity:
High humidity affects drying times, adhesion, and the risk of mould. Avoid painting when humidity is above roughly 70%. If unavoidable, choose fast-drying acrylic paints and ensure good airflow.
Rainfall:
For exterior trims, don’t paint if rain is expected within 48 hours. Even if paint feels dry, it may not be fully cured. Dew on cool mornings—common in coastal areas—can also cause moisture issues. Paint mid-morning once surfaces are dry.
Temperature:
Most paints perform best between 10°C and 30°C. In high heat, paint may dry too fast and leave brush marks. Work in shaded areas when possible.
7. Notes for Different Door Types
Interior Doors:
Usually straightforward. Ventilation is important to avoid trapping moisture.
Exterior Doors:
These need weatherproof primer and topcoat. Timber may expand or shrink with temperature changes, so choose flexible exterior paints.
Bathroom and Laundry Doors:
Constant exposure to moisture means mould-resistant acrylic paint is best. Ensure the surfaces are fully dry before starting.
Metal-Framed Doors:
Use etch primer and avoid heavy sanding that removes protective coatings.
8. Final Touches and Maintenance
Once the paint is cured—usually 7–14 days—clean gently with a damp cloth if needed. Avoid harsh chemicals.
To keep trims looking fresh:
Repaint exterior trims every 5–7 years depending on exposure, check for early signs of cracking or moisture damage, and clean dust gently from time to time.
Conclusion
Painting door trims in Australia’s varied climate requires good preparation, the right paint choices, and awareness of humidity, temperature, and rainfall. By following proper steps—cleaning, sanding, priming, and painting carefully—you can achieve a professional, long-lasting finish whether you’re updating an interior door or protecting exterior frames from harsh weather.
