How do I strip old paint or varnish?

Stripping is slow and messy whichever method you choose, so the decision is which trade-off suits the surface. Detail favours chemicals, flat areas favour heat, and thin coatings favour sanding.

Safety

What you'll need

• Scraper
• Dust sheets
• Gloves and eye protection
• Heat gun (optional)
• Chemical stripper (optional)
• Respirator (optional)

Step by step

1. Check for lead paint first.In buildings from before the late 1970s, assume it is present until tested. Test kits are inexpensive. Never dry sand or heat suspected lead paint.
2. Decide whether stripping is necessary at all.Sound paint can often be sanded lightly, filled and repainted. Stripping is for paint that is thick, flaking, or hiding detail you want back.
3. Protect the area thoroughly.Dust sheets, masking, and ventilation. Stripping generates a great deal of debris, and chemical stripper damages floors and surfaces.
4. Use a heat gun for thick paint on flat solid timber.Keep it moving, never hold it in one place, and scrape as the paint softens. Watch for smoke and never use it near glass or on suspected lead paint.
5. Use chemical stripper for mouldings and detail.It reaches into profiles a scraper cannot. Apply thickly, leave for the stated time, and remove with a shaped scraper or a stiff brush.
6. Neutralise and clean after chemical stripping.Follow the product instructions — usually washing down with water or white spirit. Residue prevents the new finish adhering.
7. Sand only as a finishing step.Sanding a thick paint layer is slow and generates a great deal of dust. Use it to smooth after stripping rather than as the primary method.
8. Fill, prime and finish promptly.Bare stripped timber absorbs moisture and dirt. Prime it within a day or two rather than leaving it exposed.

Tips

• Test the method on a small hidden area first. Some old paints react unexpectedly and some timber scorches easily under a heat gun.
• For intricate items like doors and spindles, professional dip-stripping is often cheaper than the hours it would take by hand.
• Collect debris as you go rather than at the end. Paint fragments get trodden through the house otherwise.

Common mistakes

• Sanding old paint without testing for lead — Lead dust is a serious health hazard, particularly for children. Testing costs very little and takes minutes.
• Holding a heat gun still — It scorches the timber and can ignite dust or material behind the trim. Keep it moving constantly.
• Not neutralising after chemical stripping — Residue prevents the new paint adhering, so the finish fails within months.

Questions people ask