What are the steps for painting and finishing wooden doors?
Do it yourself · Finishing
FinishingPainting a wooden door
Nine out of ten failed paint jobs go wrong before the first brushstroke. This is the order that does work, with the mistakes everyone makes.
- Take the door off first
- Thin and often wins
- Exterior door: paint the bottom edge too
Where it usually goes wrong
A door is an awkward surface: it stands upright, it has edges, and it has to close without sticking.
Paint does not stick to dirt, grease or gloss. If you quickly paint over a door without degreasing and sanding off the sheen, you will see the new coat peel off in sheets within a year. The preparation is not the boring part of the job — it is the job.
The second problem is position. A door left hanging upright while you paint gets runs on the vertical parts. Taking it off and laying it flat on two trestles solves that in one go, and you can paint the top and bottom edges at the same time.
On an exterior door, that bottom edge is crucial. Untreated wood on the underside soaks up moisture like a sponge; the door swells, sticks and rots from below. Yet that is exactly the surface almost nobody paints.
Water-based paint does not form a closed film when it is too cold, and does not dry through when it is too damp. Below 8 °C or above 80 % humidity you are better off not starting — not even in an unheated garage.
- Take the door off
- yes — working flat prevents runs
- Sanding
- grit 120 to 180, always with the grain
- Primer
- always on bare wood; an isolating primer on knots
- Number of topcoats
- two thin coats, not one thick one
- Drying time between coats
- follow the tin; if in doubt, wait longer
- Top and bottom edges
- paint them too, especially outdoors
- Temperature
- 8 to 25 °C, not in full sun
To be fair: painting a door takes two days, not an afternoon. You have to wait between coats, and you cannot make up that waiting time. If you want to finish in one day, you get a coat that is still sticking to the frame months later.
Take the door off its hinges
A door left hanging upright while you paint gets runs on the vertical parts. Taking it off and laying it flat on two trestles solves that in one go — and you can do the top and bottom edges straight away.
Click a chapter or use the arrows · coats and runs drawn enlarged, waiting times speeded up.
From fittings off to fittings back on
Do not skip a step. Every skipped step comes back as a visible flaw.
- Fittings offRemove the handle, escutcheon, strike plate and hinge pins. Masking around fittings always looks messier than taking them off, and paint in a lock is impossible to get out.
- Take it off and lay it flatOn two trestles, with a dust sheet underneath. That way you paint without runs and can do the narrow edges as well.
- Degrease and cleanA degreaser or ammonia solution removes hand grease, nicotine and kitchen residue. Rinse and let it dry.
- Fill any damageWood filler in holes and cracks, slightly overfilled because filler shrinks. Let it harden before you sand.
- SandingGrit 120 to break the gloss and smooth out unevenness, then 180 for the final surface. With the grain, never across it. Remove the dust with a damp cloth.
- PrimerAlways on bare wood. On knots in pine or spruce use an isolating primer, otherwise the resin spots bleed through the topcoat.
- Light sanding between coatsGrit 220 over the dry primer. This is the step that makes the difference between smooth and almost smooth.
- First topcoatRoll or brush it out thinly, then immediately lay off wet-on-wet with a dry brush in the direction of the grain.
- Second topcoatOnly once the first is really dry. Thin again. Two thin coats cover better and will not crack later.
- Fittings back onAt least 24 hours after the last coat. The paint is then dry but not yet cured — rehang the door carefully.
Which finish for which wood
Not every species takes every paint equally well. Oily tropical species even repel water-based paint.
| Wood species | What works | Why |
|---|---|---|
| Oak | stain or oil, or an opaque paint | the grain is worth showing; tannic acid can bleed through water-based paint, though |
| Pine and spruce | isolating primer + opaque paint | otherwise the knots bleed brown through the topcoat |
| Meranti | primer + opaque paint | a common exterior door wood, takes opaque paint well |
| Mahogany and sapele | clear varnish or oil | the colour is the point; covering it is a shame |
| Teak | oil or nothing | too oily for paint — the oil in the wood pushes the coat off |
| Plywood and MDF | primer + latex or gloss paint | the end grain soaks it up; prime those edges separately first |
Water-based paint does not yellow, smells less and dries faster — for interior doors almost always the better choice. Solvent-based gloss flows out more smoothly and is harder, which helps on an exterior door that takes a lot of punishment. Never mix the two in one system without a suitable adhesion primer in between.
Four techniques that make the difference
Laying off wet-on-wet
Roll or brush out a strip and lay it off straight away with an almost dry brush, along the grain, from top to bottom in one stroke. That makes roller and brush marks disappear.
Panel door: from the inside out
First the panels, then the vertical stiles, then the horizontal rails. The other way round, paint runs out of the corners and dries on parts you had already finished.
Foam roller on flat areas
On a flush door, a fine foam roller gives a more even result than a brush — provided you lay off wet-on-wet.
Match the bristles to the binder
Synthetic bristles for water-based paint, natural bristles for solvent-based. The other way round, a natural-bristle brush soaks up water and splays.
Five mistakes and what caused them
| What you see | Cause | What to do about it |
|---|---|---|
| Runs and sags | coat too thick, door upright | let it cure, sand back, repaint more thinly — and work flat |
| Air bubbles | rolled too fast, or paint shaken instead of stirred | roll calmly, stir the paint, and do not use a worn roller |
| Brown spots through the coat | resinous knots without an isolating primer | sand back to bare wood, apply isolating primer, repaint |
| The door sticks to the frame | closed too early or applied too thickly | let it cure with the door open; talcum powder on the rebate helps temporarily |
| Bare patches after one winter | not degreased or not sanded to a matt surface | no quick fix: strip it right back and build the coats up again |
How to make it last
A painted interior door needs little: wipe it with a damp cloth and mild soap, no abrasive cleaner. An exterior door is another story. Check it every spring for hairline cracks, especially at the bottom rail and around the fittings, and touch them up before water can get in.
A door facing south or west gets the full sun and driving rain. Expect to touch it up every three to four years there, compared with seven to ten years for a sheltered door facing north. Waiting until the coat has really failed always means sanding it all the way back.
Frequently asked questions about painting wooden doors
Do I really have to take the door off?
You do not have to, but it makes a difference to the result. Lying flat, the paint does not run, and you can paint the top and bottom edges — exactly the surfaces where moisture otherwise gets in.
Which grit of sandpaper should I use?
Grit 120 to take off the gloss and level the surface, 180 for the final surface before the primer, and 220 lightly between coats. Always with the grain.
Why do my knots bleed through the paint?
Pine and spruce contain resin that works its way through an ordinary primer. Use an isolating primer on the knots, or on the whole door.
Can I use water-based paint over old solvent-based paint?
Only after thorough degreasing, sanding and an adhesion primer. Without that intermediate step the new coat does not stick and peels off in sheets.
How long should I wait before closing the door?
Dry is not cured. After the last coat, leave the door open for at least 24 hours; most paints take several weeks to cure fully.
At what temperature can I paint?
Between roughly 8 and 25 °C, and not in full sun. Too cold means no closed film; too warm means the paint dries before you can lay it off.
Would you rather not paint?
Outdoor furniture in pressure-treated spruce or in hardwood never needs painting — that is exactly why we supply it that way.
Have a question about your project? Just ask — we're happy to help.
Photos via Wikimedia Commons: Wooden garage door sanded back to bare wood, ready for refinishing — Dynamic Painting, CC BY 4.0 · Old wooden door with flaking green paint — Irene Grassi, CC BY-SA 2.0