A wood hardener is for repairing timber decayed by wet rot, particularly in window and door joinery, which binds and strengthens loose wood fibres prior to filling. Ideal for joinery and doors.

Key information

Pack sizes

Application information

As required (normally 2-3 coats)
Touch dry
6 hours dependent upon temperature / humidity
Recoat before previous coat is dry
This product should not be thinned.

Key benefits

  • Strengthens, hardens and binds loose wood fibres in decayed wood.
  • Solvent-based colourless treatment
  • Ideal for use with Ultra Tough Wood Filler
  • Can be used outdoors and indoors

System information

Identify the full extent of any decay, by probing the wood with a sharp instrument. Cut out all badly decayed and very soft wood. Remove paint, varnish, dirt or loose material from the area for repair and immediately around it for about 25-50mm (1- 2 inches). If wood is wet, allow it to dry thoroughly before applying the wood hardener.

Apply liberally by brush to the repair area and immediately around it. Apply 2-3 coats, allowing each to soak in before the next coat is applied. Do not allow previous coat to dry fully before the next is applied.


Brand: Cuprinol Trade

Size: 500ML

Type: Problem Solving Primer

Cuprinol Trade Ultra Tough Wood Hardener 500ML header image

£13.30Ex. VAT: £11.08

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