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How to prepare and paint interior woodwork

We asked London-based painting and decorating team English Barrett & Gray for their advice on preparing and painting interior woodwork.

Refresh your interior woodwork

Skirting boards, window and door frames can all benefit from being refreshed with new paint. The way that you approach preparation and painting of interior wood work depends on whether you’re working with bare wood or wood that has already been painted.

Before you start

Remove or protect furniture and cover the floor with a dustsheet. If you’re working on a skirting board, tuck masking tape around the edge of the carpet or flooring.

Always follow the manufacturer’s instructions on products or tools and wear suitable clothing, a mask and goggles, where appropriate. 

Preparing and painting bare wood

1. Knotting solution

Wood today is often very young, which means it’s full of sap. Over time, this sap leaks out and ruins paintwork if not properly treated first.

Paint on two or three light coats of knotting solution, allowing 30 minutes between each coat.

2. Fill and caulk

Fill any holes, cracks or imperfections in the wood with a specialist wood filler. Apply sparingly, as using too much will leave you sanding away the excess.

If a crack has formed between the join of the woodwork and the wall, fill and seal this with caulk – a waterproof substance which is sold in a cartridge and applied with a gun. This can be fiddly, so follow manufacturer’s instructions carefully.

Masking tape on windows can be more trouble than it’s worth. But, if you’re not confident of achieving straight lines without it, spend a little extra on a high quality tape. Cheap masking tape leaves a residue behind.

Masking tape also deteriorates with exposure to air, so store yours in an airtight bag or container.

3. Primer and undercoat

One coat of wood primer creates an adhesive surface for the paint to cling to. Allow to dry.

Next, apply undercoat thinly to avoid drips, working with the grain of the wood for a smooth finish. On bare wood, two coats are usually enough.

The topcoat—whether gloss, satin or eggshell finish–adds texture rather than colour, so add a third layer of undercoat for full coverage if needed.

Alternatively, combined primer undercoat paints are available – you’ll need three or four coats.

4. Topcoat

Once the undercoat is dry, you can add the topcoat. Resist the temptation to slap this on thickly and continue to work with the grain, which could be different for each section of a panelled door.

Start at the top and work downward to avoid drips. You should only apply one coat.

Preparing and painting painted wood

1. Strip or sand

If the existing paintwork is in extremely poor order, you could use a heat gun, which costs about £15, to strip the surface back to bare wood. Be careful not to burn the wood.

Don't attempt to strip lead paint (sometimes found in old houses) with a heat gun – seek advice from a reputable painter and decorator.

Paintwork with only a few light blemishes can be prepared by sanding. Don’t completely remove the paint. Simply remove imperfections and give the woodwork a 'key' – an adhesive surface for the new paint to cling to.

A sanding machine can be used cautiously for a large surface if preferred. Be very careful not to strip away too much paint.

2. Clean

Use a damp cloth or an industrial wipe to remove grease, grime and the sanding dust. Sugar soap can also be used but don’t soak the woodwork.

Don’t buy cheap paints – the colours look fine initially but a white paint, for example, will often yellow prematurely.'

3. Undercoat

Once completely dry, paint one coat of undercoat. Work with the grain and apply thinly. Allow to dry.

4. Topcoat

Finish with one coat of gloss, satin or eggshell finish paint, as per the instructions for bare wood.

The key to a good finish is patience and attention to detail. Don’t cut corners and spend time on completing each step thoroughly.

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