Timber Door Stripping and Repainting in London

When Stripping Is the Right Choice

Over decades of repainting, London's period doors accumulate layer upon layer of paint. In properties across Belgravia, Chelsea and Pimlico, it is not uncommon to find ten or more coats of paint on a single front door. Eventually, the build-up obscures moulding profiles, prevents doors from closing properly and creates a surface that no amount of sanding can salvage.

At this point, stripping back to bare timber and starting fresh is the only way to restore the door to its original crispness. The question is which stripping method to choose — each has distinct advantages and drawbacks.

Method 1: Caustic Dip Stripping

Caustic dipping involves submerging the entire door in a tank of sodium hydroxide solution. The chemical dissolves paint layers rapidly, usually within 24 to 48 hours.

Advantages:

• Removes all paint in one operation, including from deep mouldings and panel recesses
• Cost-effective for batch stripping (multiple doors at once)
• No risk of heat damage or scorching

Drawbacks:

• The door must be removed from its frame and transported to a stripping tank
• Caustic solution raises the grain of the timber significantly
• Can loosen traditional mortise and tenon joints if the door is left submerged too long
• Requires thorough neutralisation and extended drying time — timber can take two to four weeks to dry fully

For Victorian panelled doors in Kensington and Fulham, caustic dipping is often the most efficient option when dealing with heavy paint build-up. However, we would not recommend it for doors with delicate veneers or inlaid panels.

Method 2: Heat Gun Stripping

A professional heat gun softens paint to the point where it can be scraped away with a broad blade or shavehook. This method keeps the door in situ — a significant advantage when the door frame and hinges are in good order.

Advantages:

• No chemicals involved
• Door stays hung in its frame throughout
• Immediate — no waiting for dipping or chemical reaction
• Does not affect the timber's moisture content

Drawbacks:

• Labour-intensive, particularly on complex moulded panels
• Risk of scorching the timber if the gun is held too close or for too long
• Generates fumes from melting paint — adequate ventilation and respiratory protection are essential
• Lead paint risk: pre-1960s doors may contain lead paint, which releases toxic fumes when heated

We use infrared paint strippers as an alternative to conventional heat guns on many projects. These operate at a lower temperature, reducing scorch risk and minimising fume generation. For homes in Westminster and Mayfair where lead paint is likely, infrared stripping combined with a HEPA vacuum extraction system is our preferred approach.

Method 3: Chemical Paint Stripper

Paste-based chemical strippers are applied to the painted surface, covered with a protective sheet, and left to work for several hours or overnight. The softened paint is then scraped away.

Advantages:

• Gentle on timber — no heat, no water immersion
• Can be applied in situ without removing the door
• Effective on detailed mouldings when allowed sufficient dwell time
• Lower risk with lead paint than heat methods

Drawbacks:

• Multiple applications may be needed for heavy paint build-up
• Chemical strippers can be expensive for large areas
• Some products contain methylene chloride or NMP — always check the safety data sheet
• Slower than heat or caustic methods

For high-value doors — original Georgian six-panel doors in Belgravia, for instance — chemical stripping offers the safest, most controlled approach, preserving fine timber detail without the risks associated with heat or immersion.

Choosing the Right Method

The best stripping method depends on several factors:

| Factor | Caustic Dip | Heat Gun | Chemical Strip | |--------|------------|----------|---------------| | Heavy build-up (10+ coats) | Excellent | Slow | Moderate | | Door stays hung | No | Yes | Yes | | Lead paint safety | Good | Poor | Good | | Timber preservation | Moderate | Good | Excellent | | Cost | Low | Moderate | Higher | | Speed | Fast | Moderate | Slow |

Repainting After Stripping

Once stripped, the bare timber requires careful preparation before repainting:

1. Sanding: Start with 80-grit to remove any residual paint and smooth raised grain, progressing through 120-grit and finishing with 180-grit.
2. Knotting: Apply knotting solution to any resinous knots to prevent bleed-through.
3. Priming: An oil-based wood primer provides the best foundation, particularly on softwood doors common in Victorian properties.
4. Undercoat: One or two coats of undercoat build opacity and a smooth surface for the topcoat.
5. Topcoat: Two coats of exterior gloss or eggshell for front doors; interior doors can receive satinwood or eggshell for a more contemporary look.

Between each coat, we lightly sand with 240-grit paper to ensure inter-coat adhesion and remove any nibs or dust particles.

Front Doors: Special Considerations

London front doors face the full force of weather, pollution and UV exposure. For properties in Chelsea and Knightsbridge, a front door is also a statement of quality. We apply a minimum three-coat system (primer, undercoat, topcoat) to exterior faces, with additional coats on the bottom rail where water exposure is greatest.

Contact us for a survey of your doors and a tailored recommendation on the best stripping and repainting approach.