DIY Advice – Varnishing Wood
HOW TO VARNISH WOOD:
1.Choose a well-lit, well-ventilated area.
2.Choose an area that is free of dust and dirt.
3.Pay attention to the temperature and humidity. The temperature in the area you will be varnishing should be between about 21°C to 26°C. If it is too hot, the varnish will dry too quickly, resulting in tiny air bubbles forming.
4.Wear proper protection.
Varnishing the wood
- Prepare the varnish for the initial coat, if necessary.Some varnishes, such as those that come in a spray can, do not need any preparation; other types of varnishes should be thinned for the first coat. This helps seal the wood and prepare it for the proceeding coats. The rest of the coats do not need to be thinned.
- If you are using an oil-based varnish, thin it with a paint thinner, such as turpentine. Use one part varnish to one part thinner.
- If you are using a water-based or acrylic-based varnish, thin it with water instead. Use one part varnish to one part water.
2 Apply the first coat of thinned varnish and let it dry. Use a flat paintbrush or foam applicator to apply the varnish to the wood. Use long, even strokes, and work along the wood grain. Let this first coat dry for 24 hours.
3 Sand the first coat and wipe it with a damp cloth. After you have applied the initial coat of thinned varnish, you will need to smooth it out. You can do this by buffing the surface of the varnished wood with 280-grit sandpaper, and then using a dry cloth to wipe away any dust or debris.
- Make sure that you wipe down your work space with a damp cloth to get rid of any dust caused by the sanding.
- Make sure that you clean your brush with paint thinner (if you are using an oil-based varnish) or water (if you are using a water-based varnish).
4 Apply the next coat of varnish and allow it to dry. Using a clean brush or a new foam applicator, apply the varnish to the wooden piece. Once again, make sure that you are brushing along the wood grain. You do not have to thin this layer. Wait 24 hours for this layer to dry.
- If you are using a spray on varnish, you can spray on another coat. Make sure to keep the can 6 to 8 inches away from the surface, and spray on a single, light coat. If you spray the varnish on too thickly, you may end up with puddles, drips, and runs.
5 Sand the second coat and wipe it clean with damp cloth. Once the second coat of varnish has dried, sand it gently with a fine-grit sandpaper, such as 320-grit. Let the varnish dry 24 hours before applying the next coat, and remember to clean your work space of any dust or dirt caused by the sanding.
6 Continue applying more varnish and sanding between coats. Apply 2 to 3 more coats of varnish. Remember to let the varnish dry between coats, and to sand and wipe the varnish clean before applying more varnish. Always work along the grain when applying and sanding the varnish. When you get to the last coat, do not sand it. You can continue working with 320-grit sandpaper, or move up to 400-grit.
- For optimal results, consider waiting 48 hours before applying the final coat.
7 Wait for the varnish to finish curing. Varnish will typically need some time to finish curing. To prevent ruining the varnish, leave your wooden piece some place where it will not be disturbed.