Painting wood is one of the most popular ways to protect it and give it a fresh new look. Whether you’re painting a garden swing, coating window frames, or giving furniture a different colour — the core approach is always the same: clean, sand, prime, paint. The difference lies in the products you use and the conditions you’re working in. In this article you’ll learn exactly what you need for each situation and how to apply paint coats perfectly without streaks, runs or peeling.
Outdoor vs. indoor: which paint do you use?
| Exterior paint | Interior paint | |
|---|---|---|
| **Water resistance** | High | Low |
| **UV resistance** | Yes | No |
| **Flexibility** | High (resistant to shrinkage/expansion) | Low |
| **Drying** | Slower | Faster |
| **Use indoors?** | Yes (but more odour) | Not outside |
| **Examples** | Flexa Exterior Gloss, Sikkens Alpha Plus | Flexa Perfect Finish, Sigma Superlatex |
Always use exterior paint for outdoor projects. Interior paint will peel after 1–2 seasons outside.
Water-based vs. solvent-based paint
| Water-based (acrylic) | Solvent-based (alkyd) | |
|---|---|---|
| **Odour** | Low | High |
| **Drying** | Fast (2–4 hours) | Slow (8–24 hours) |
| **Quality** | Good (modern formulas better than before) | Slightly harder finish |
| **Application** | Brush, roller, spray | Brush, roller, spray |
| **Clean up** | Water | White spirit |
| **Environment** | More eco-friendly | More polluting |
Modern water-based exterior paints (acrylic) are comparable in quality to solvent-based paints. For most applications, water-based is fine and more pleasant to work with.
Required products and tools
| Product/tool | Purpose | Price |
|---|---|---|
| Sandpaper 80–120–180 grit | Preparation | €5 – €15 |
| Primer/undercoat | Adhesion layer for new paint | €15 – €30 |
| Brush (bristle/nylon) | Applying paint | €5 – €25 |
| 10 cm paint roller (mini roller) | Large flat surfaces | €3 – €10 |
| Masking tape | Masking edges | €3 – €8 |
| Filler | Filling small holes | €5 – €10 |
| Covering exterior paint | Final result | €20 – €50 per litre |
Step-by-step guide: painting wood in 7 steps
Step 1: Clean
Remove dirt, grease, algae growth and loose paint. Use water with washing-up liquid and a stiff brush. For window frames or garden furniture: use a specialist algae/moss remover.
Allow the wood to dry completely (at least 24–48 hours in dry weather) before continuing. Damp wood does not accept paint well.
Step 2: Sand
Sand the surface with 80–120 grit paper. This removes loose paint, levels out imperfections, and gives the new paint a keyed surface to adhere to.
Old paint in good condition? You don’t need to sand back to bare wood — a light key (grit 120–150) is sufficient.
Loose, peeling paint? Sand everything off, using a scraper or hot air gun if needed. Never paint over peeling paint — it will continue to peel.
After sanding, remove all dust with a dry cloth or compressed air.
Step 3: Fill holes
Fill small cracks, holes and gaps with interior filler (indoors) or exterior filler (outdoors). Leave to dry and sand smooth.
Tip: for wooden window frames, don’t fill the gap between wood and masonry with filler — use a flexible sealant (silicone or acrylic mastic). Filler will crack when the joint moves.
Step 4: Prime
A primer (undercoat) is almost always needed when:
- Painting new, bare wood
- Changing the colour of wood (light to dark or vice versa)
- Dealing with wood that has resin knots
- Painting metal or cast iron
Tip: use a primer that is compatible with the top coat (water-based on water-based, or solvent-based on solvent-based).
Apply the primer thinly and leave to dry fully (2–4 hours for water-based). Lightly sand after drying (grit 180) for better adhesion of the top coat.
Step 5: First coat
Apply the first coat of top coat paint. Always work with the grain on wood. Start from one end and work across.
Brush technique:
- Load: dip the brush to one third into the paint, wipe off the excess on the rim
- Apply: apply paint in long, even strokes
- Lay off: finish in the direction of the grain for a clean result
Roller technique (large flat surfaces):
Apply paint in a W or M pattern, then lay off in one direction.
Leave the first coat to dry completely (follow the drying times on the tin — typically 2–4 hours for water-based paint).
Step 6: Sand between coats
After the first coat, lightly sand with grit 180–220. This removes dust particles and imperfections in the paint film, and gives the second coat better adhesion.
Remove dust with a dry cloth.
Step 7: Second (and possibly third) coat
Apply the second coat in the same way as the first. Most paints are fully opaque after 2 coats. For strong colour changes (e.g. dark to light): 3 coats are recommended.
Final check: inspect the dried paint under daylight. Can you see streaks, runs or thin patches? Lightly sand (grit 180) and apply an additional coat.
Special situations
Painting window frames
Window frames are exposed to rain, sun and temperature changes. Always use exterior gloss or purpose-made window paint. Repaint every 3–5 years before peeling begins — this prevents deep damage.
Tip: never paint window frames in direct sunlight (paint dries too fast and bubbles form). Work in the shade or on an overcast day.
Painting furniture (indoors)
For indoor furniture: use furniture paint or chalk paint. Chalk paint adheres to almost any surface without primer — perfect for quickly refreshing IKEA furniture or vintage finds.
After chalk paint, always apply a protective coat of wax or varnish — chalk paint itself is not wear-resistant.
Covering resin knots
In spruce or pine, resin bleeds through paint (yellow stains). Apply shellac primer or knotting solution to the knots before priming.
Common mistakes
- Painting damp wood. Paint doesn’t adhere to damp wood and peels quickly. Always wait 24–48 hours after rain.
- Skipping the primer. On bare or colour-changed wood, primer is essential — otherwise the top coat will peel.
- Applying too-thick coats. Thin coats give a better result than one thick coat (runs, uneven drying).
- Paint streaks. Caused by overloading the brush or not laying off. Always work with the grain.
- Skipping the inter-coat sanding. Without sanding between coats, the second coat adheres less well.
Frequently asked questions
How much paint do I need?
As a rule of thumb: 1 litre of covering paint covers 10–15 m². Don’t forget: you’re applying at least 2 coats. Calculate the area (include the sides for window frames) and add 10% extra.
Do I need to prime previously painted wood?
On previously painted wood in good condition (not peeling), priming is not necessary — sanding and applying the top coat directly is sufficient. Strong colour change? Then a primer is still recommended.
Can I paint indoors in winter?
Minimum temperature for painting: 10°C (for water-based paint). Below this temperature, paint doesn’t cure properly and gives poor coverage. Heat the room or wait for warmer weather.
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