Why does water-based paint not last on wood work?

One common question we hear from DIY enthusiasts and homeowners alike is: Why doesn’t water-based paint last on woodwork? Whether you're painting a balustrade, doors, or skirting boards, water-based paints often seem to peel or chip sooner than traditional oil-based paints.

In this post, we’ll explain why water-based paints sometimes fail on wood, how to identify the type of paint you're working with, and most importantly, how to achieve a durable, professional finish that lasts for years.

The Main Issue with Water-Based Paint on Woodwork

The primary problem lies in adhesion. Water-based paints don't always stick well to previously painted surfaces, especially if those surfaces are coated with oil-based paint. If you simply apply water-based paint over old oil-based paint, you'll likely notice issues such as:

• Poor adhesion: The new paint may flake or peel over time.

• Runs and drips: Water-based paints can be more prone to runs if not applied correctly.

• Quick marking: Light contact can leave visible marks, and the paint may seem less durable.

  
  

  

  Oil based paint on right starting to yellow Vs water based paint on left.

  
  

How to Tell if Your Woodwork Has Oil or Water-Based Paint

Identifying the type of old paint is crucial before you start painting. Here are some simple methods:

• Perform a White Spirit Test: Dab white spirit onto a cloth and rub it on the painted surface. If the paint softens or comes away, it’s likely water-based paint. (Note: Not all DIYers have white spirit or want to do this test.)

• Look at the Finish: Shiny, yellowish paint—especially gloss—is often oil-based. If the surface is more matte or has a whiter appearance, it’s probably water-based.

• Check the Surface: Fresh or new skirting boards typically use water-based satin finishes, whereas older, shiny finishes are often oil-based.

  
  

  

  
  

How to Paint Over Oil-Based Paint on Woodwork (Step-by-Step Guide)

If you're planning to paint over existing oil-based paint with a water-based finish, proper preparation is key for longevity and a smooth finish. Here's what you need to do:

1. Use a Suitable Primer

Applying a primer creates a firm attachment between the old oil-based paint and your new water-based finish. Recommended primers include:

• Zinsser Bin Aqua: Widely available and effective.

• Johnstone’s Trade Joncryl Primer: Known for excellent adhesion over oil paints.

• Dulux Trade Uniprimer: A newly released primer which is good and reliable choice for bridging different paint finishes.

2. Prepare the Surface

• Lightly sand any imperfections and glossy areas to improve adhesion.

• Clean the surface to remove dust, grease, or any contaminants.

3. Apply the Primer

• Use a quality primer, following the manufacturer’s instructions.

• Let it dry completely before applying your topcoat.

4. Paint with Quality Water-Based Paint

Once primed, choose a durable, high-quality water-based finish:

• Johnstone’s Trade Aqua Guard Satinwood: Highly durable, ideal for woodwork.

• Dulux Trade Satinwood: A popular, reliable option.

• Alternative: Johnstone’s Satin (less durable but budget-friendly).

Using a good-quality topcoat enhances durability and gives your woodwork a professional appearance that lasts.

Painting Tips for a Perfect Finish

• Use a Medium Pile Roller: A 4-inch roller helps apply a smooth, even coat without streaks or runs.

• Apply Thin Layers: Multiple thin coats are better than one thick coat—they dry faster and look better.

• Sand Between Coats: Lightly sand imperfections before applying the next layer.

  
  

  

  
  

Final Thoughts

Achieving long-lasting, flawless woodwork paint requires the right preparation, suitable primer, and quality paints. By following these tips, you'll extend the lifespan of your paint job and enjoy beautifully finished wood surfaces for years to come.

If you’re unsure about your current paint situation or need professional assistance, don’t hesitate to contact us — we’re here to help!