Choose the right time and place
Some experts recommend laying the door flat on a pair of trestles for decorating. This has some advantages: it’s easier to avoid drips when working on a horizontal surface; with no frame, you can reach every part of the top and bottom edges; and painting the hardware cut-outs is simpler because you won’t have to fit the hinges and handles until afterwards.
On the other hand, doors are heavy, difficult to manoeuvre and take up a lot of space. The trestles might leave contact marks behind; and you will have to wait several hours for the first side to dry before you can paint the second one.
In practice, most home owners prefer to decorate the door in the frame. Wait for a warm day (at least 10°C) with no wind, to avoid dust being blown on to the wet paint. Don’t work in strong sunlight as the paint may blister. Wedge the door open before you start, and place some cardboard underneath to catch drips.
If your door is supplied unfinished, begin by lightly sanding it all over with a fine grit sandpaper, before wiping down with a damp cloth to remove dust. Stick masking tape around the edges of any glass panels to stop them getting splashed. Some doors come with a protective plastic film over the glass which can be peeled away after installation, but you may want to use masking tape as an extra precaution.
Buy good brushes
Use good quality brushes with natural bristles. A cheap brush is a waste of time – the paint won’t flow from it properly and it is likely to keep shedding hairs while you work. A 100mm (4″) brush is a good size for large surfaces, as it offers good coverage but won’t get too heavy when filled with paint. You will find a 25mm (1″) brush handy for cutting in (painting into the corners) and tackling intricate areas such as beading and cut-outs.
Before you start, gently flick and pull the bristles to dislodge any loose ones, then rinse the brush in clean water. This will not only get rid of dust, but also help prevent paint from drying on the bristles. Avoid using a new brush for the first time on the top coat – always ‘break it in’ on an undercoat.
If you would rather not have brush marks on your door, try a high density foam mini roller. This lets you cover panels quite quickly, and will produce a smoother finish than a brush. You can turn the roller on its end to get into corners and tight spaces.
Unless you have ordered a pre-primed door, you will have to apply a stain-blocking primer – ideally two coats – to provide a base for the rest of your paint work. Pay special attention to the top and bottom of the door, which are particularly vulnerable to water penetration.
Apply primer equally all over on both sides, not forgetting the cut-out holes for hardware. This will seal the timber and keep incoming moisture to a minimum, preventing swelling (which can make the door stick on the frame). Conversely, it will also help stop the door from drying out and shrinking in hot weather.
Take care with top coats
Once the base coat has dried you can get to work on the first top coat. Start with the edges of the door, so you can get rid of any paint ridges when you tackle the main face. If the two sides of the door are going to be decorated in different colours, paint the outer edge (by the handle) to match the inside of the door, and the hinged edge to match the outside.
Unless it’s a flush door, you will now need to paint the edges of each panel, followed by the face. On large flat expanses, brush or roll up and down, then from side to side, and finally up and down again to spread the paint out evenly and prevent runs. Smooth out drips straight away before they set hard.
Use at least two coats of good quality exterior grade paint. If your door is engineered and veneered, check first that the paint is suitable for this type of construction. Acrylic latex paint is highly recommended, as it will flex with the timber and help prevent cracking. Choose from matt, satin, semi-gloss or gloss finishes. Allow to dry according to the manufacturer’s instructions – normally between four and six hours.
After each coat has dried, lightly sand the entire door with fine grit sandpaper and wipe with a damp cloth to remove dust. This will provide the smoothest possible base for the next coat, and help you achieve a professional-looking finish.
Leave ample time for the door to dry before use. It would be a great shame, after all your hard work, if paint stuck to the frame because it hadn’t fully dried.