Depending on exposure to sunlight, the linseed oil paint will eventually fade, something that will be visible on the south sides first. This is due to the linseed oil naturally degrading and does not need any immediate action. When the paint is completely matt, it gets ”chalky” ie it will smear when touched. Linseed oil paint does not flake off from the substrate.
The chalking can be a positive thing as the paint ”washes itself” as dirt and mould/algae erodes from the surface. However, this could entail negative practical consequenses with smearing outdoor furniture. We would like to point out that the degradation is only superficial and that linseed oil paint has close to eternal life span internally.
Maintenance with linseed oil and turpentine on coarse sawn surface
Clean the surface if needed. Mix equal amounts of raw linseed oil and turpentine and apply one thin layer. Check that the linseed oil has penetrated the surface and wipe off excess oil with a dry brush.
Linseed oil maintenance on smooth planed surfaces
Clean the surface and apply raw or boiled linseed oil in thin layers. Wipe off excess oil after half an hour and the paint has regained its original color and shine.
Repainting
When a surface painted with linseed oil is matt, you might think it is time to repaint. For sustainability reason, there is no need to repaint. Linseed oil paint outdoors have long durability with a matt appearence. There is no need to repaint for 8 to 15 years. Repainting is a matter of aesthetics rather than sustainability.