DO-IT-YOURSELF : Restore Hardwood Floor, Start to Finish

If you decide to tackle restoring a worn hardwood floor that has a clear finish, plan on a week’s worth of work.

You will need a day to prepare the space and gather materials and tools, another to sand and several more to apply the finish and allow drying time between coats. You can save time by asking someone to help you.

Preparation and Tools

If a finish is severely damaged and the flooring is at least one-fourth inch thick, it should be stripped with a sander before refinishing. You can rent equipment. A drum-type floor sander handles most of the floor refinishing. Use a hand-held disc sander, or edger, to sand stair treads and along baseboards, in corners, inside closets and in other places that are inaccessible to the large drum sander. Hand-sand spots that neither sander reaches.

Have a salesperson show you how to operate the machines and how to change the sandpaper. Stock up on sandpaper and be sure that you have the right tools for attaching the sandpaper to the sanders.

Prepare for sanding by removing all rugs, furniture and other furnishings in the room. Carefully take off the quarter-round shoe moldings along the baseboards. (Number the moldings and their places on the wall so that you can put them back.) Cover all vents. Seal doorways and windows from the rest of the house with plastic sheeting.

Inspect the floor carefully. Pull out any staples left from carpeting. Drive any visible nailheads one-eighth inch below the surface using a nail set and fill the holes with wood putty. Repair cracks and secure loose floorboards. Vacuum and thoroughly inspect the floor once more.

Sanding

For sanding, wear goggles, a dust mask and ear protection. To avoid marring the floor, don heavy socks or clean, white-soled sneakers. Remember that sanding dust, finishes and finish fumes are flammable. Don’t smoke. Extinguish pilot lights on nearby appliances.

Sand the floor first with the drum sander and 36-grit paper. Raise the sander off the floor, turn on the power, then lower the drum carefully, keeping a firm grip on the handles. Work across the floor--always with the grain--then return to the beginning and strip the next section parallel to and slightly overlapping the first.

Using an industrial drum floor sander is like walking a headstrong dog. Your job is to let it pull you, but not as fast as it can. Always keep the machines moving or the sander will “eat down” into the floor and leave an uneven surface. Wearing work gloves will ease the pressure on your hands. Repeat the sanding process twice, using 80-grit sandpaper, then 100-grit paper.

Next, sand along the walls with the edger. Hold both handles firmly and keep the disc flat on the floor to avoid gouging. Sand with the same succession of paper grades as you used on the main floor.

Use a block of wood wrapped with sandpaper or a paint scraper to clean even the tightest areas--in corners and under radiators--where neither power sander can reach. Finally, hand-sand, working with the grain, to remove swirls caused by the edger. Vacuum thoroughly between sanding stages.

Apply Finish

After sanding, vacuum the floor and walls using the brush attachment. Wipe down moldings, windowsills and door frames so that dust won’t fall off later and mar the finish. Let dust settle overnight, then vacuum again. Wipe the floor thoroughly with a tack cloth, available in hardware stores.

If you want floors to be only slightly darker than the bare wood, apply sealant of any kind. If you want the finish to have a darker tone, apply wood stain before the sealant.

Oil-base polyurethane is a popular floor finish because of its durability and ease of application. You need three coats when you use polyurethane as the final finish. Thin the first coat with one part mineral spirits to four parts polyurethane; this acts as a sealer.

Brush polyurethane across the grain and then along it. Use a long-handled roller to apply the finish on the main surface of the floor; use a small brush for the edges and corners.

Work in small sections, overlapping the strokes before the previous section is dry. Inexpensive foam rollers are best; just throw them away instead of cleaning them between coats.

Let each coat dry as directed before re-coating; observe ventilation precautions on the container. In between coats, buff with a rented floor-polishing machine equipped with superfine steel wool. After each buffing, vacuum well and clean with a tack cloth.

Allow the finish to dry at least two days, then buff with superfine steel wool again and vacuum.