Wood Hardener Penetrating Epoxy

Penetrating Epoxy Wood Hardener is a thin epoxy that penetrates deeply into rotten timber. Designed in the 70’s for restoring rotten structural timbers in boats it is now available in the UK. Use it in conjunction with our Fill-It epoxy filler to restore profiles after hardening the rotten timber.

Penetrating Epoxy Wood Hardener – FAQ

When do I need an epoxy wood hardener?

You use our Penetrating Epoxy Wood Hardener to:

• Consolidate, harden and restore strength to timber that has rotted
• It finds rot that you cannot see, restores strength and allows permanent repairs
• Outperform all others on the market:
  • Repairs performed with one part wood hardeners typically fail after a year. They fail to find all the rot – so the wood carries on rotting under the repair!
  • We believe our unique solvent blend and quality flexible resin blend outperforms all other 2 part epoxy formulations available. The resin remains as flexible as wood once cured – which keeps it bonded to the timber fibres
• Do permanent repairs to rotten timber. Do it once – do it right – make wood good

Why is CPES the best penetrating epoxy wood hardener?

Our Penetrating Epoxy Wood Hardener (CPES) is the best penetrating epoxy for wood because it:

• Is carried in a unique solvent blend that ensures deep penetration into the wood fibres or rot.
• Stays bonded to the wood fibres as it is crafted using expensive resins that once cured flex with the wood itself. This furthermore makes it resistant to knocks as it flexes rather than cracks under impacts.

What is the difference between Cold and Warm Weather Formulas?

The two formulas are designed to work at different temperatures. as such they have:

• Different curing properties – CW formula cures faster at any given temperature. It is designed to give similar working and curing times to Warm Weather formula but achieved at lower temperatures
• Different solvent blends – Warm Weather Formula is less volatile, so evaporates slower at any given temperature
• We invariably recommend usign Warm Weather Formula for treating deep areas of rot. The more volatile solvents evaporate faster and allow the job to be completed quicker

Do I have to prime timber after treating it with Smiths Penetrating epoxy wood sealer?

No – Clear Penetrating Epoxy Wood hardener is also the worlds best wood primer because it:

• Glues your topcoat to your wood – CPES forms chemical bonds to almost every modern topcoat as it’s slow curing formulation is still curing when the initial topcoat is applied to the timber
• Penetrates deeply providing a sound and secure base for your topcoat, be it varnish or paint
• Enhances the beauty of your timber by bringing out the grain of it
• Can give you varnish finishes that last up to 20 years with proper maintenance

Treating all of your window or door after treating the rot will significantly enhance the durability of your top coat – helping to prevent future rot.

Can I use fillers on top of timber treated with CPES?

Yes, you can use fillers on top of Clear Penetrating Epoxy Wood Hardener. We recommend our own Fill-It lightweight flexible and waterproof filler, which you can buy at a discount with CPES included as a rotten wood repair kit, but any decent filler will adhere to CPES. Always ensure the solvents have evaporated fully to ensure you have a stable base before applying filler.

More penetrating epoxy wood hardener questions and answers can be found here.

Why Smiths Clear Penetrating Epoxy Sealer (CPES) is the best Epoxy Wood Hardener

There are a variety of single part wood hardeners available on the UK market. Most are made of an acrylic plastic dissolved in a solvent like styrene. Our Smiths CPES Wood hardener is a penetrating epoxy that differs from these products in the following ways:

• You can achieve permanent repairs
  • CPES penetrates deeply and finds all rot, including rot not visible to the naked eye
  • No more re-doing the job the next year
• External repairs that last
  • Because epoxies are permanently waterproof
  • As CPES flexes with the natural movement of wood
  • Since CPES bonds tightly and permanently to the wood fibres
• Highly compatible with fillers, sealers and surface finishes
  • For best results, use our Fill-It epoxy filler; it will flex with wood, is permanent and waterproof too
  • Modern caulks, hybrids and polyurethanes will bond tenaciously to it
  • It’s the perfect primer for paint and varnish too

This is why our two part epoxy wood hardener will always outperform any single part wood hardener.

Much more can be read about the restoration of rotted wood at woodrestoration.com

CPES Penetration into timber

New timber penetration

Smiths CPES Wood hardener penetrates 8cm of new beech end grain in 3 minutes.

Rotten timber penetration

It can completely consolidate a section of rotten timber into a solid block of plasticised wood.

Previously I found the piece of completely rotted wood shown below underneath a window in my house. It was so crumbly that I could turn it to dust with my fingertips alone.

Repairing rot with Smiths CPES Timber Hardener

Here are the six steps to rotten wood restoration in pictures:

1. Shows a typical section of rotten timber
2. Firstly remove crumbly rotten wood by flaking it out with your fingertips
3. Then consolidate the remaining rotten timber with Smiths CPES Penetrating Epoxy wood consolidator
4. Following that fill any missing sections of timber with Fill-It epoxy wood filler
5. Then sand to restore profiles
6. Repeat till exterior profile is perfect

Should you wish to buy Fill-It epoxy filler as well as Smiths penetrating epoxy wood hardener, they can be purchased together at a discount as a rotten wood repair kit.

Hardening Spalted Timber

We have had many customers over the years harden spalted (partially rotted) timber with CPES. The timber is strong enough when treated to be worked and finished, and durable enough to last as well.

See how Paul Fowler hardened the spalted Wood Nymph here.