Sweep or vacuum the stairs, removing as much dust and dirt as possible. Remove any metal corner pieces, so you are left with only the wood.
Check the stairs for nails or screws sticking out of the wood. If there are any, pound or screw them back into place. Fill any holes with wood filler.
Begin with 50 or 60 grit sandpaper on your sander. A palm, random orbital or belt sander will help you to remove the finish. Sand in the direction of the wood grain or you may scratch the surface. The sander should constantly be on the move so you do not gouge the wood.
Using a paint scraper, scrape the corners to remove the varnish. A file will sharpen the scraper when it begins to dull. You can also use a special triangle shaped sander called a mouse.
Vacuum the dust from the stairs and then wipe them with a cloth to remove all sanding particles.
Switch to number 100-grit sandpaper. This time do the sanding by hand. This step is important to do well if you plan on staining the oak stairs.
Clean the dust made by the hand sanding. Now you are ready to stain the wood, if desired. After staining, apply two to three coats of polyurethane and sand with #120 sandpaper between coats of polyurethane, vacuuming and wiping away dust particles after each sanding.
Things You Will Need
- Vacuum cleaner
- #50, 60, 100 grit sandpaper
- Palm, random orbital or belt sander
- Paint scraper
- Sanding mouse
- Do not apply the polyurethane on a humid or rainy day. Not only will it not dry, it could blush, or cloud, the finish.
- If the stairs are used on a daily basis, work on every other step.
- Sanding between each polyurethane coat will allow the coats to adhere better.
- You can also remove sanding residue with baby wipes.