Pine panels are easy to install, and may be painted or finished in a wide range of colors or shades. If you want to lighten the varnish of your pine panels, you have to remove the old finish and prepare the wood to varnish it again with a lighter shade of varnish. This may be a time consuming process, but you won’t need to remove the panels from the wall.
Step 1 – Prepare the Space
You don’t have to remove the pine panels from the wall, which saves you a lot of time. However, you have to protect the floors using dropcloths or old newspapers. Remove any items that are close to the pine panels or cover them with a plastic tarp.
Step 2 – Clean the Panels
Remove all dust and debris from the panels. Clean them with a moist cloth and diluted vinegar or detergent, and wipe them dry.
Step 3 -- Sand the Panels
Wear a protective mask when you use sandpaper or a sander, to prevent the inhalation of small wooden particles. Use a rough grit sandpaper (e.g. 80 grit) to remove the old finish of the pine panels. Remove all the dust that is formed after sanding the entire surface. Sand the surface again with a medium or fine grit sandpaper this time (e.g. 120 grit or 220 grit). Wipe the surface with a piece of moist cloth, and allow the surface to dry before you proceed.
Step 4 – Even the Surface
If you find any holes, use wood putty and a putty knife to fill them. You may use epoxy mixed with sawdust instead of putty. Allow the putty to dry completely. If necessary, wait until the second day before you start applying the varnish.
Step 5 -- Apply Build-Up Coats
Apply several build-up coats of varnish. You may use the same varnish you'll use for the final coat for the buildup coats, but you can also opt for less expensive varnishes for this step. The build-up coats are necessary to prepare the wood and make the finish more durable. These coats have the same role for the varnish as primer for paint. Allow each build-up coat to dry before you move on to the next step.
Step 6 – Sand the Surface
Even the surface by sanding it with a fine grit sandpaper. Wipe away the dust.
Step 7 – Apply Finish Coats
Use a paintbrush or a paint roller to apply the varnish to the pine panels. Apply a thin coat of varnish and allow to dry. Apply 1 or 2 more coats of varnish until you obtain the desired shade of varnish. Sand between each coat of varnish with a fine grit sandpaper.
Check if the surfaces are completely dry before you start removing the protective newspapers and tarps from around the pine panels.