Stripping and repairing original trim
Applies to: Assumes painted softwood or hardwood interior trim of unknown age with multiple accumulated paint layers.
Last worked on 2015-01-08
The reason to strip trim is almost always detail rather than colour: enough coats and the profile that made the moulding worth having has gone.
Decide what you are stripping for
If the aim is to recover a crisp profile, stripping is the only route and the work is in the detail, not the flat. If the aim is a sound surface for repainting, you rarely need to go to bare timber: keying, filling and spot-stripping the failed areas is faster and less damaging.
If the aim is a clear finish, be certain the timber underneath is worth showing before committing. Much painted trim was painted because it was made from several species, or from short jointed lengths, or because it was never intended to be seen.
Order of operations
Remove hardware and label it. Take the trim off only if it will come off without splitting - fixings in old trim are often cut nails that will not withdraw, and forcing them destroys the piece you are trying to save.
Work the flats first and the detail last, because the flats are where you develop a feel for how the layers are releasing, and the detail is where a mistake is permanent.
Repairing before finishing
Splits and open joints should be repaired before final sanding, not after, so that the repair is levelled with everything around it. Consolidating soft areas and then filling is more durable than filling alone, because filler bonded to failing timber fails with it.
Where a section is missing entirely, a let-in patch of the same species running the same way as the surrounding grain will move with the piece. A filled void of that size will crack along its edges within a season.
The finish decides the sanding
A painted finish forgives a great deal and needs less final work than people expect. A clear finish shows every scratch and every trace of remaining stripper, and it also shows every difference in the timber that the paint had been concealing.
The last grade of abrasive used should be chosen for the finish, not by habit: too fine a surface can prevent some finishes keying properly.
Sequence
- Record the profile and take a short offcut or a template before any material is removed.
- Remove and label hardware.
- Test-strip a small concealed area to find out how many layers there are and how they release.
- Strip flats, then details, working with tools shaped to the profile rather than flat ones.
- Neutralise and let the timber dry fully before assessing what needs repair.
- Consolidate soft timber, then let in patches, then fill only the remaining small defects.
- Sand to the grade the chosen finish needs, and no finer.
Most trim that gets replaced could have been repaired. The decisive factor is nearly always whether a template was taken before the work started.