How Do I Paint Exterior Hardwoods?Updated 2 years ago
Treating wood can be a minefield with so many products to choose from, not to mention the array of characteristics found in different types of timber.
Typically, more care is needed with softwoods due to weaknesses like knots, splits, lack of durability, blue stain, etc., but the tendency with hardwoods is to retain the natural grain appearance, often resulting in under-application of coating, and subsequent earlier breakdown.
That said, some hardwoods can be very difficult to paint because they have an oily surface (see notes below). The key before an application is to remove all surface oils using cellulose thinner and rinse with clean water.
Prone to tannin bleed
Coloured timbers such as oak, Western red cedar and idigbo are prone to tannin bleed. Degrease with cellulose thinner and ensure the timber is thoroughly coated all around (with particular attention to the end grains).
Contains acidic tannins which discolour with metal fixings
Hardwoods including Oak, Western Red Cedar and Idigbo. Degrease with cellulose thinners and avoid the use of steel (ferrous) fixings.
Contain oils/gums/extractives (slow drying and poor adhesion)
Hardwoods including Teak, Iroko and Keruing. Degrease with cellulose thinners and allow extra drying time.
Priming Options
Intermediate
Pinja Flex Isolator (exterior blocking primer)
Topcoat Options
If you require more advice on painting over hardwoods, give our technical team a call on 0131 334 4999 or send a message to our technical team.