Timber iQ April - May 2018 // Issue: 37 | Page 40

FEATURES Coating and / or painting a timber surface does require some knowledge, therefore research is mandatory to reach the desired effect. Paint it well, coat it well Wood is a building material that is versatile and flexible, so clients may choose to paint or coat it; we look at how this can be done while ensuring longevity of the wood. By Ntsako Khosa | Photos by Pixabay I t is not often that clients request timber to be used on a job, so it is important to do some research first and ask questions such as what type of timber will be used, where will the material be placed (indoor or outdoor), which product works best for the material, will it require maintenance after painting or coating? “The basic rules hold true for all types of timber types: preparation, application and using the right products are all essential, irrespective of the timber type you are treating,” says Frikkie Greeff, Woodoc MD. PREPARING TIMBER Once all of this has been determined, preparation is the next step. Stefan le Hanie from Howard Products says that when it comes to preparation, it depends on the finish of the timber. “An antique for example would be treated by one of our products. Restor-A-Finish preserves the original wood finish. It also helps preserve its authenticity.” “There are different types of wood and each has a different characteristic that needs consideration prior to 38 APRIL / MAY 2018 // application of a coating,” says Guy Lawson, director at My Law Chemicals and Excelsior Paints. The procedure may vary from wood types, but the same basic principles apply and include: • Checking the moisture content in the wood first (the wood must have a moisture content below 20% before coating or the coating can fail); • The wood must be abraded with sand paper to open the wood grain and allow the coating to penetrate (different woods have different porosities); and • Any residue like resin from the wood knots and dust and contaminants must be treated or removed before coating. Carel Steenkamp, senior product specialist at Rubio Monocoat, says that this step is key. “Ensure that any filling is done and the fillers drying times are respected before moving on to sanding,” he advises. See more on page 40