Preparing Interior Wood For Painting

Looking for a room refresh? Getting a lasting, professional paint finish all comes down to the preparation. We know that sanding and filling might not be the most exciting part of your project. But putting the effort into your painting wood preparation is the secret to a result you can be proud of.

Whether you're touching up chipped skirting boards or transforming an entire room, doing the prep work properly makes sure your fresh paint binds to the surface and lasts for years. And we're here to guide you through every step.

To get you started, try watching our short how-to video at the top of this page. It's full of advice to show you exactly how to prepare wood for painting.

Or if you prefer to read, we've broken down everything you need to know below - from how to prepare old wood for painting to how to prepare bare wood for painting, we'll help you get the job done right.

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Preparation

Preparing previously painted woodwork

Preparing new woodwork

Staying safe

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Clean your woodwork thoroughly with sugar soap and warm water to remove all dirt, grease, and grime before you start painting.
Fill any cracks with wood filler, then sand the surface lightly to create a key so your fresh paint binds properly.
Treat knots in bare wood with a knotting solution, then apply a water-based primer and undercoat to ensure a lasting finish.

Preparing for the job

When preparing wood for painting, you’ll need to do a few things first.

Before you pick up a scraper or a paintbrush, you need to protect your room. Lay down heavy-duty protective dust sheets over your floor and cover any furniture you can't move out of the way.

Your main goal is to make sure the woodwork is completely free from dirt, dust and grime. It's also vital to sort out any surface imperfections like bubbles, cracks and flakes before you begin.

How to prepare previously painted woodwork

If your woodwork has been painted before, follow these steps.

Start by checking for holes and cracks. Place some wood filler onto a filling knife and work it into these imperfections. Leave it to dry, following the manufacturer's instructions.

Then, use a firm scraper to remove any excess filler until you have a smooth surface. Add more filler if you need to and leave it to dry again.

Once the filler is dry, open your windows to ventilate the room and put on a dust mask.

Wrap sandpaper around a block of wood or use a sanding block. Always sand the filled areas in the direction of the grain until the surface is level.

To prepare painted wood for painting, use fine sandpaper to lightly sand down the rest of the wood. This removes minor imperfections and creates a rough 'key' that helps your new paint bind to the surface. The steps are exactly the same if you’re looking at how to prepare stained wood for painting or how to prepare varnished wood for painting.

Next, brush down and vacuum the whole area thoroughly. This stops stray dust from getting caught in your damp paint.

Finally, use a sponge to liberally apply sugar soap across the surfaces. Always wear protective gloves for this job. Wipe the surfaces down, rinse the sugar soap off with warm water, and let the wood dry completely.

How to prepare new woodwork

If your woodwork is brand new and unprimed, you’ll need to follow these steps.

If you're working with bare, unpainted wood, make sure it's clean first. Use sugar soap and a damp cloth to clean it.

Then, look closely at the grain for any knots. You'll need to treat these with two coats of knotting solution. This stops the natural wood resin from leaking into your fresh paintwork later on. Be sure to follow manufacturer’s instructions on application and drying times.

Once the knotting solution is dry, you can prepare bare wood for painting by applying a primer. This ensures a durable finish.

Let the primer dry thoroughly, then apply an undercoat. We suggest trying a low-odour, water-based primer undercoat. Because it's quick drying, you can usually apply two coats in just one day.

Staying safe

Always wear protective gloves when you handle filler or sugar soap.

When you're sanding, make sure you ventilate the space well. And remember to wear your dust mask and safety goggles.

Keep the room well-ventilated while painting and take regular breaks - especially if you're using solvent-based paints.

Once your paint is completely dry, interior woodwork needs very little maintenance.

But excessive moisture can make wood swell. Dry off any condensation quickly, particularly around window frames.

Avoid using chemical-based cleaners, as these might damage your new finish.

And that's the hard part done. Putting the effort into your preparation now rewards you with a paint finish that looks professional and lasts for many years.

Now your interior woodwork is completely prepped, you're ready for the fun part. Check out our guides on how to transform your interior woodwork for some top painting tips, and on how to paint interior woodwork for the steps to complete the project.

FAQs

You need to completely remove the wax before painting, or the paint won't stick. Use a wax and polish remover with wire wool to lift the old wax. Wipe it clean, let it dry, and then sand the surface lightly to create a key.

Remove the cabinet doors and hardware first. Clean them thoroughly with sugar soap to remove grease and grime. Lightly sand the surfaces, wipe away the dust, and apply a good quality wood primer before you start painting.

Treat panelling just like any other interior wood. Fill any cracks or nail holes with wood filler. Sand the surface lightly, vacuum the dust, and clean with sugar soap. Apply a primer if it's bare wood, or an undercoat if it's already painted.