Refinishing a wooden school desk will take sanding, varnish and multiple days.
Several options are available for refinishing a wooden school desk. They include: straight polyurethane; tung oil or Danish oil with an overcoat of polyurethane; varnishes; commercially-blended table top finishes sold at many home improvement centers; and special bar epoxies. Factors to consider when choosing the finish for a wooden school desk are durability, longevity, overall appearance and ease of application. According to the publishers of Fine Woodworking's "Traditional Finishing Techniques," a high-gloss spar varnish--which can be found in most home improvement centers--provides a durable, clear, easy to apply finish that works well for desks. Does this Spark an idea?
Instructions
1. Strip existing paint or varnish from the desk. Use a standard chemical paint or varnish remover to soften the existing finish so that it can be scraped away. Follow the directions and safety precautions that come with the product.
2. Sand the desk to prepare it to accept new varnish. On most hardwoods, such as maple, start sanding with a 100-grit course sandpaper, Fine Woodworking's "Traditional Finishing Techniques" suggests. Continue sanding with finer grades of sandpaper. A standard routine would include sanding with 120 grit, then 150 grit and ending with 220-grit sandpaper.
3. Mix three parts of high-gloss spar varnish with one part of turpentine. Combine the two products in a container that allows for easy pouring, such as in a plastic cup. Mix only enough to provide one coat of coverage to the desk. Be sure to follow any safety directions included with the varnish, particularly any related to working in a well-ventilated area.
4. Pour the varnish onto the top of the desk and quickly rub it in with your hands. Wear latex gloves during this part of the process, and be sure to have a plastic drop cloth underneath the desk. According to Fine Woodworking's "Traditional Finishing Techniques," you should work large areas at a time. Working small areas may leave a line where different areas of finish overlap.
5. Sand the still wet varnish into the wood with 220 grit wet-or-dry sandpaper. Wet-or-dry sandpaper is a specialty sandpaper that can withstand exposure to liquids. It is available in most home improvement stores. Sand with the direction of the grain of the wood -- or in other words, parallel to the grain. Sand until the varnish thickens and becomes slurry-like.
6. Wipe the still wet varnish to remove any excess that has not soaked into the wood. Use a cotton rag free of lint to wipe the excess varnish. Wipe across the grain of the wood -- or in other words, perpendicular to the grain. Work quickly. The longer the excess varnish remains on the wood, the stickier and more difficult it becomes to remove.
7. Buff the desk with a clean cloth during the first several hours of drying time. Check the piece about every 30 minutes for any spots where excess varnish has started to seep up from the surface of the wood. Immediately wipe the excess varnish away. Keep checking the piece until at least an hour has passed without any excess finish emerging. Allow the desk to dry overnight at room temperature.
8. Sand the desk with 320-grit sandpaper once the varnish has dried overnight. Clean any sanding dust from the piece with a vacuum or with compressed air. Then pour undiluted, high gloss spar varnish onto the finished surface. For this coat and subsequent coats, do not mix the spar varnish with turpentine. Sand the varnish into the wood as before, but this time use 320 grit wet-or-dry sandpaper. Wipe off excess varnish, check regularly, and allow to dry overnight.
9. Repeat the sanding and varnishing process with finer grits of sandpaper. After allowing to dry overnight, sand with a 400 grit paper. Clean the piece of dust and apply the varnish with 400 grit wet-or-dry sandpaper. Wipe off excess varnish, check regularly, and allow to dry overnight. At this point, you've provided a reasonable finish for the desk, but you can continue with additional finishes. Work your way up to 600-grit sandpaper for a finish that provides longer wear and greater sheen.
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