I recently completed a project where the requirements were to apply colour to the exterior timber windows using Intergrain ‘Natural Stain’ in charcoal, without the need of an exterior oil or water-based acrylic top coat.
This particular project was a new construction with new exterior timber windows having been installed over two months ago. The timber windows have had sufficient time to weather and thus allow the leaching of the tannins and oils to stop. It is important to remove leaching tannins and oils because it will prevent issues like discolouration and poor adhesion once the top coats are applied. As I was using an Intergarin product, it is recommended to use an Intergrain timber cleaner called ‘Reviva‘ to help restore grey, tannin stained or mould and rust affected timber to its original appearance ready for coating.
By mixing a ratio of 1 part Reviva and 4 parts water, I applied the mixture to the windows using a medium-stiff brush. Allowing to stand for 10-15 minutes, I then removed the the mixture with fresh water and allowed the windows to dry ready for the ‘Natural Stain‘ coatings. Depending on the condition of the timber, you may require another application of the Reviva mixture to further clean the timber surface. On completion of drying the windows were checked for any knots and nail holes and they were filled with a timber filler, lightly sanded and ready for the top coats as shown below.
After giving the ‘Natural Stain‘ a good stir, I began to apply the stain directly to the window, making sure that I complete each section first before starting the next. It is important to keep and maintain a wet edge when applying a stain, with the first coat, because it absorbs into the timber a lot quicker then the second and third coats and you don’t want to have overlapping brush marks. The picture below shows the first coat being applied.
Allowing 2-3 hrs drying time depending on the weather, if necessary you can sand lightly between coats to remove any raised timber grain. Applying the second coat of ‘Natural Stain’ will naturally darken the timber as shown below.
It is recommended to use two to three coats of ‘Natural Stain‘ and is dependent on how dark you want the timber to look. In this particular case I used three coats more so for better protection of the elements as it was not required to apply an exterior coating of top coat varnish. The end result is shown below.
Here are some more pictures of the Intergrain ‘Natural Stain’ applied to other timber windows on this project.