Using timber brightener to return timber to its original colour
Over time, the colour of timber exposed to UVs and humidity without protection will change. It will naturally turn a grey-silver colour, which will be its final colour. The application of a brightener to the wood will remove the grey surface and return the timber to its original colour.
Why does timber grey?
UVs, water, temperature and oxygen are all contributors to the change in the colour of timber. Subjected to these external elements, the unprotected surface of the timber will first become lighter and then take on a more or less consistent grey colour. This colour change is caused by the deterioration of the lignin.[1] In contact with UVs, the lignin deteriorates into 2 molecules by photo-oxidation. These molecules are subject to leaching. The consequence of this chemical change to the surface of the timber is also its change in colour, which will become more and more grey.
Brightening the timber
Timber is only brightened on the surface. The application of a wood brightener will act on the surface layer that has been altered by UVs. This product, which is usually based on oxalic acid, acts like a wood bleaching agent.
Combined with a rubbing action after its application using a soft brush, the wood brightener revives the greyed or tarnished aspect of the timber.
Once the timber has been brightened
There are two solutions:
– let the surface of the timber age naturally and go back to grey
– or, to prevent the change in colour and protect the surface of the timber, surface coating, lacquer, saturator, oil and water repellent UV products can be applied.
[1] Lignin represents 20 to,30% of the timber. It is the binder that assembles the cellulose molecules. Its chemical structure varies widely from species to species, depending on location, age, etc. It is naturally hydrophobe and vulnerable to UVs.