Wood Hardeners

Wood hardener is a thin, solvent-based liquid resin designed to be absorbed deep into the fibres of soft, porous, or decaying wood. It is not a filler or a glue, but a consolidant, a product that strengthens and reinforces weakened wood from the inside out.

Once applied, the thin liquid soaks into the punky wood fibres. The solvent carrier then evaporates, leaving behind the powerful binding resins. These resins cure and harden, effectively binding the previously soft wood fibres together into a solid, stable mass.

This process provides a solid foundation in the wood, making it ready for the next stage of a repair, which is typically filling the area with a durable Wood Filler. It essentially saves wood that might otherwise need to be completely replaced.

Using wood hardener correctly is the essential first step in a permanent wood repair. The process is straightforward, but the preparation and application are key.

1. Prepare the Wood: The wood must be completely dry before you begin. Use a scraper or wire brush to remove any loose, crumbling, or very soft rotted wood. You want to get back to a base of wood that is still intact, even if it feels soft or punky.
2. Apply Liberally: Using a disposable brush, apply the wood hardener generously to the affected area. The liquid is very thin, so it will soak in quickly.
3. Saturate the Fibres: Continue to apply coats of the hardener every few minutes until the wood stops absorbing it. This is how you know the fibres are fully saturated with the resin.
4. Allow to Cure: Let the wood hardener cure completely. This can take several hours, depending on the temperature and how much was absorbed. The surface should be hard and no longer tacky to the touch.
5. Fill the Repair: Once fully cured, the hardened wood now provides a solid anchor for the next step. You can now apply a durable wood filler (like an epoxy or polyester filler) to rebuild the damaged area before sanding and painting.

You should use wood hardener specifically on areas of wood that have become soft, porous, or "punky" due to the early stages of rot or decay. It is the perfect solution for wood that has lost its structural integrity but has not yet completely crumbled away.

Think of it as the first step in a two-part repair system for rotted wood.

Use wood hardener on:

• Rotted wooden window sills and frames.
• Soft spots on exterior door frames.
• Decaying sections of fence posts or garden furniture.
• Any wood that feels soft and spongy but is still physically present.

When NOT to use it:

• It is not a wood filler. It cannot rebuild missing sections or fill holes on its own.
• It is not a wood glue. It is not designed for joining two separate pieces of wood.
• It cannot fix wood that is structurally failed or has completely disintegrated.

In short, if you can press into the wood and it feels soft, use wood hardener first to solidify that area. Then, use a wood filler to complete the repair.