You may not be able to push enough filler into hairline cracks to ensure a good bond:
• it is often better to open the crack up further with the edge of an old chisel or screwdriver so the filler can penetrate more deeply and key better to both sides of the crack
• when using a textured vinyl paint there is no need to fill hairline cracks, but cracks wider than 1mm should be filled.
DEALING WITH FITTINGS
Protect electrical fittings so paint or water can’t enter them during cleaning and decorating:
• ideally, power to these fittings should be cut off and the fittings removed
• if items cannot be removed, use masking tape to protect them.