The reasons for this are matters of science, including the fact that solar radiation (sunlight) will inevitably have an effect on trasparent coatings. However once you understand the variables involved in coating timber it is possible to preserve it's natural beauty for years to come.

Sunlight (solar radiation) is comprised of visible light (46%) infrared light (50%) and UV light (4%). It is the UV portion of the light spectrum that is most destructive to coatings of any type, clear or pigmented. In some respects, both visible and infra-red also have their effect, but more in the form of heat transfer.

All transparent coatings allow transmission of sunlight so that we can see the grain of the timber through the coating. In the absence of opaque pigments that reflect light most modern clear coatings rely on some inherent light-resistance through the choice of resins and formulation with UV-absorbers or light stabiliser additives to increase longevity. These additives are typically very small particles that are not visible to the human eye but do scatter some light.

A clear coating acts to protect the timber from deterioration and will serve to give it longevity. It also acts to prevent mould-spores from growing and helps prevent the grain and wood from splitting, an effect that may result after many years of exposure.

Although transparent coatings do not last as long as pigmented coatings there is just something about the asthetic of well preserved timber. When specifying timber and coatings it is important to be aware that ongoing maintenance will be required to counteract the natural deterioration of the timber and coatings through light exposure. It is difficult to prescribe a fit all maintenance schedule as it is dependent on many variables including the species of timber, the amount of exposure to solar radiation and weather exposure.

The Cabot's and Intergrain product lines have been developed and tested for NZ conditions and timbers.