How do I fill nail holes so they do not show?
Small holes show after painting for two reasons: they were filled proud and sanded into a halo, or they were not sealed. Both are easy to avoid once you know they are the causes.
- Difficulty
- beginner
- Time
- 20 min
- Read
- 2 min
Short answer
Punch the nail below the surface first, press filler in with a fingertip or a small knife, wipe the excess off the surrounding surface immediately, and seal the spot before painting. Do not build a mound and sand it — that scuffs the surrounding paint and creates a visible ring.
Filling a nail hole is the smallest job in decorating and one of the most commonly visible afterwards, especially on woodwork in gloss. The two mistakes are so easy to make that most people make both: leaving a proud lump that has to be sanded, and painting over bare filler that then dries to a different sheen.
Step by step
- Punch the pin below the surface first.A nail punch sets the head a couple of millimetres down so there is somewhere for filler to go. Filling over a proud or flush head leaves a lump and the head will show through the paint anyway.
- Choose a filler that suits the surface.Fine surface filler on painted woodwork and walls; a wood filler matched to the timber if the finish will be clear or stained rather than painted. On a stained finish, colour matters enormously and is worth testing first.
- Press it in rather than smearing it across.Push filler into the hole so it fills the whole depth, then take the excess off. A smear laid over the top bridges the hole with a void underneath and sinks later.
- Wipe the surrounding surface clean immediately.This is the step that avoids sanding. A damp cloth or fingertip takes the excess off the sound surface while it is soft, leaving filler only in the hole. Then there is almost nothing to sand.
- Sand only if you must, and only the spot.If it dried proud, use fine abrasive on a small block and confine it to the repair. Sanding wide scuffs the surrounding paint and creates a dull ring that shows through the new coat.
- Expect to fill twice on deeper holes.Filler shrinks. A hole that looked full often shows a small dimple once dry. A second, very thin application fixes it and takes seconds.
- Seal the filled spots before painting.Bare filler is absorbent. On gloss especially, unsealed spots read as dull dots through the finish. Spot-prime them.
Tips
- On a clear or stained finish, fill after staining rather than before wherever possible — filler takes stain differently and usually ends up too light or too dark.
- For a run of pin holes in new architrave, fill them all, wipe them all, then come back and do the second pass in one go.
Common mistakes
- Leaving a proud blob to sand back later. — Sanding it scuffs the paint around it, and that halo is more visible than the hole was.
- Painting straight over the filler. — The porosity difference shows as a dull spot, particularly under gloss and sheen finishes.
Questions people ask
Can I use decorator's caulk for nail holes?
It works at a pinch but it cannot be sanded and stays slightly flexible, so it tends to look soft. Filler is better anywhere the finish matters.
What about holes in a stained or waxed finish?
Use a wax filler stick or a coloured wood filler chosen against the finished colour, and test on an offcut. Ordinary white filler is very obvious under a clear coat.