How to remove old varnish from a door

To remove old varnish from a door, you can use varnish stripper and a scraper, or sand it. Stripper is faster on thick layers, but requires gloves, a mask and plenty of ventilation. Sanding creates more dust and takes longer. In older houses, first check whether there is lead in the layers of paint.

Safety first

Varnish strippers are strong products. The fumes irritate and the skin can be burned with prolonged contact. Always read the label and follow the manufacturer's instructions.

In older houses, very old layers of paint or varnish may contain lead. Do not dry sand without assessing the risk. Lead dust is dangerous, especially for children and pregnant women. If you have any suspicion, seek advice before starting.

Removing with varnish stripper

If the door is hung, protect the wall and the frame with tape and plastic. If you can take it off, work horizontally, on trestles, because then the stripper does not run.

  1. Apply the stripper with an old brush, in a generous coat, in one direction.
  2. Leave it to work for the time stated on the label. The varnish will lift and blister.
  3. Remove it with a plastic or metal scraper, always in the direction of the wood grain.
  4. In recesses and mouldings, use a wooden stick, a soft-bristled brush or fine wire wool.
  5. Repeat if varnish remains in the harder areas.

Do not press hard with the scraper. If the wood gets scratched, you will see the scratches after painting or revarnishing.

Cleaning off the stripper residue

After scraping, clean the door as the product label directs. Some call for a thinner, others for water. If residue remains, the new varnish or paint will not adhere well.

Leave the wood to dry completely. Depending on the product and the weather, it may need a full day or more. If the wood is still damp, the paint or varnish may blister.

Tip: Cloths and wire wool with stripper on them should be left to dry in the open air, well spread out, before being thrown away. Do not pile them up.

Removing by sanding

If the varnish is thin, you can sand it. Start with a medium grit sandpaper and then move to a finer one. Always sand in the direction of the grain, so as not to leave visible scratches.

For flat areas, use a sanding block. For mouldings, use an abrasive sponge or folded sandpaper. Avoid aggressive sanders on thin wooden doors, because they can remove too much material.

If you sand, wear a dust mask and vacuum thoroughly at the end. Wipe with a well-wrung damp cloth and leave to dry.

What to do next

With the wood clean and dry, choose the finish. To keep the wood visible, apply a varnish or oil made for interiors. To paint, use a suitable primer and enamel, as on any door.

Do a test in a hidden corner before treating the whole door. That way you can see the colour of the wood and how it reacts to the new finish. Woods that darken with age can surprise you once cleaned.

See also