Before painting a door
Remove all handles etc before starting and lay newspaper under the door to prevent your brush picking up dust.
Wedge the door in an open position to hold it steady while painting.
Which part of the door frame to paint
Many people are confused as to which part of the frame belongs to which room when painting. The answer is that all frame edges up to and including the ones against which the door closes belong to the room into which it opens.
It is generally better to paint the frame before the door. Painting it afterward will inevitably lead to the brush marking the part dry paint on the door.
If in doubt, let one dry before painting the other.
Painting door edges
Door edges must always be painted before the face for the same reason.
When painting the face of a door, work slightly outwards at the edges rather than inwards to avoid what the trade call ‘fat edges’
Flush doors
Flush doors can be painted using the same system as for wall areas. Note that if you decide to use a roller for speed, the finish will be less smooth than using a brush because the roller leaves a slight orange peel effect. This may be overcome by laying-off each section with a brush once it has been rollered, as you work, but will require some practice.
Panelled doors
The sequence for this is very important if a good finish is to be achieved. Lay off each piece along its longest dimension.
Start by painting the mouldings, taking care not to overload them as this will lead to runs.
Next, paint the panels themselves.
Then the edge of the door.
Follow this by the vertical pieces between the top panels.
Then paint the cross rail at the top, the top half of both stiles, the vertical section between the bottom panels, the lock rail, then the bottom rail.
Finally, paint the bottom half of the outer vertical pieces.
Take care to blend the joins between sections.
You will need to work reasonably quickly to get good results.
Experienced painters adopt different techniques but these rely on skill and speed which can only develop with practice. They often paint a panelled door in a very similar way to a flush door.