Wood Finishes and Coatings

Finishing wood is the process of protecting it from damage and enhancing its natural beauty. A proper finish not only looks great but also provides a durable barrier against moisture, scratches, and everyday wear.

The process involves several key stages:

1. Sanding: This is the most critical preparation step. Start with a medium-grit sandpaper to level the surface and remove any machine marks. Progress to a finer grit to create a perfectly smooth surface. Always sand in the direction of the wood grain.
2. Cleaning: After sanding, remove every trace of dust. Use a vacuum followed by a wipe with a tack cloth for the best results.
3. Staining (Optional): If you want to change the colour of the wood, apply a wood stain at this stage. Allow it to penetrate and then wipe off the excess.
4. Sealing / Priming: Apply a sanding sealer or a primer. This seals the pores of the wood, prevents the final coats from soaking in unevenly, and creates a uniform base.
5. Applying the Topcoat: This is your protective layer. Whether you choose a varnish, lacquer, or paint, apply it in thin, even coats. Lightly sand with a very fine grit sandpaper between each coat (after it has dried) to remove any imperfections, ensuring a flawlessly smooth final finish.

Yes, you can absolutely paint over wood that has an existing finish, like varnish or lacquer. In fact, it's one of the most common DIY projects. However, you cannot simply paint directly onto the glossy, sealed surface.

For the new paint to adhere properly and not peel off, you must prepare the surface correctly first.

The essential steps are:

• Clean Thoroughly: First, the surface must be cleaned with a good degreaser to remove all traces of wax, furniture polish, oil, and grime that have built up over the years.
• De-gloss the Surface: The key to adhesion is removing the slick, glossy nature of the old finish. Use a medium-grit sandpaper to scuff the entire surface. Your goal is not to remove the old finish completely, but to dull it down and create a fine texture, or "key," for the new primer to grip onto.
• Prime: After sanding and cleaning away the dust, apply a high-quality adhesion primer. A good primer will bond strongly to the old finish and provide the perfect foundation for your new paint, ensuring it won't chip or peel.

The method for repairing a damaged wood finish depends entirely on the severity of the damage.

For light scratches and scuffs where the damage is only in the top clear coat, you can use touch-up markers or a matching paste wax. For more widespread light scratching, you can often lightly sand the entire surface with a fine-grit paper and apply a fresh coat of the same clear finish to restore it.

For deeper gouges and chips that go through the finish and into the wood itself, you will need to fill the area. You can use wax filler sticks for areas that won't see a lot of wear. For a permanent, hard repair, clean out the damaged area and fill it with a wood filler. Overfill the repair slightly, allow it to dry completely, and then sand it perfectly flush with the surrounding wood before applying a new topcoat.