The most commonly used system for exterior dressed timber is 1 coat of Cetol HLSe followed by 2 coats of Cetol Filter 7 plus.
There are a number of factors which determine the durability of any coating.
- The species of timber. Some species are more stable than others.
- The cut of the timber. Quarter sawn timber is much more stable than crown cut timber and should be used in sunny exposed situations wherever possible.
- The aspect. A north facing structure will suffer much more UV damage than a south facing structure.
- The situation. An exposed building site close to the sea will be subjected to the abrasive effects of salt laden winds more so than a sheltered inland site.
In the worst case the coating will require a maintenance coat after 1 year.
In the best case a maintenance coat may not be required for 8 years.
Any previous coating must be completely removed prior to coating with Sikkens. It may be possible to remove the oil residue with Jac Jay Timber Revitaliser.
Sanding should be carried out with great care as any variation in coating thickness will present itself as a colour variation and may look patchy. Use only fine sandpaper such as 320 grit or finer.
Cetol Filter 7 plus is a flexible coating designed to expand and contract with changes in temperature. To achieve a similar appearance indoors with better wear resistance we recommend coating with Cetol HLSe followed by Cetol TS Interior.
Teak and some other hardwoods are naturally oily. These oils retard the drying of all surface coatings and will also impair the adhesion of the coating. Oily timber should be thoroughly degreased with white or methylated spirits prior to coating. Wet, cold and humid conditions also slow down drying time.
The HLSe/Filter 7 plus system has a higher gloss and film build and is the preferred system on front doors, garage doors and other joinery. We recommend the HLSe only system on weatherboards as it is easier to maintain.