Floorboard manufacturers and installers often finish their products with varnish, a clear, thick coating that protects the wood from damage and stains. The varnish adds a polished appearance to the floor. Over time, dragging furniture, foot traffic and general wear and tear cause scratches on the floorboards. More than likely, the scratches only go as deep as the varnish itself, and repairing them returns the floorboards to their classic looks.
Scrub at the scratch with a small toothbrush or soft scrub brush to remove dirt and debris from inside the scratch. Wipe down the scratch as well as the area two to three inches to either side with a rag dampened in white spirit to remove dirt and dust.
Soak a piece of 400-grit wet/dry sandpaper in a bowl of cold water for 10 minutes until the paper is thoroughly saturated. Lightly sand the scratched area until the area feels smooth to the touch. The sandpaper lightens the edges of the scratches and brings it flush with the rest of the floor.
Wipe down the area with a tack cloth to remove sanding dust and inspect your work. If the scratch is gone, proceed to the final Step.
Colour in the scratch with a wood touch-up pen. Make sure you match the colour to the rest of the wood. This blends all but deep scratches in the varnish. When the pen dries, inspect the area. If the scratch is gone, proceed to the final Step.
Melt the tip of a wood wax repair stick with a lighter. As the wax melts, spread it into the scratched area with a putty knife or scraper. This fills in the scratch. Allow the wax to dry before continuing.
Re-varnish the area with the same varnish used on the rest of the floor, if possible. Lightly dampen a paintbrush in the varnish and brush it across the entire area you repaired and sanded, gradually lifting the brush as you move outside the area to blend the new varnish with the old. Allow the varnish to dry; apply a second coat only if needed for a darker colour to match the rest of the floor.
If the scratches penetrate the wood of the floorboards, you need to use wood filler and a putty knife to fill in the areas. Proceed to sand the area and varnish after you fill the scratch and the filler has time to dry fully. If you fill in the scratch with wood wax, shellac or wood filler, you may need to paint the grain of the wood over the repair work to blend it with the rest of the floor. Use a dark brown or black paint and a fine-tip paintbrush to trace the grain through the repair area from one side to the other.