Your oak stair banisters are probably one of the most highly trafficked areas in your house. Whether you want to change their look or simply restore them to their original lustre, re-staining the banisters is one of the best ways to preserve and maintain them. Oak is a variety of wood that accepts stains predictably and evenly. There's more to the job than applying a coat of stain, however. Preparing the wood to properly accept the stain and applying polyurethane to protect the stained wood are equally important.
Tape off the spindles, newel posts and any other area you don't want to stain. Depending on how experienced you are, you'll want to tape just the areas closest to the banister or lager areas. Also, cover the treads, risers and surrounding flooring with dust sheets.
Remove all existing stain, polyurethane and other coatings from the banister. A variety of chemical and nontoxic strippers are available for this. Apply liberal amounts and allow the stripper to cure according to the instructions for the product you choose. Once the stripper has cured, scrape it off with a paint scraper taking care not to scratch the banister.
Sand the banister thoroughly. Use 120- or 150-grit sandpaper on all surfaces of the banister. This will remove any scratches and remnants of previous coatings. Sanding also opens up the pores of the wood to accept the new coat of stain. After sanding, wipe the banister with a dampened tack cloth to remove dust and debris.
Brush on wood conditioner. This product, available at many home improvement stores, ensures that the wood absorbs the stain evenly and thoroughly. Allow the conditioner to cure for 15 minutes before applying the stain.
Select a stain. Options include water-based and oil-based stains in a variety of colours. Oil-based stains are generally considered more durable and better able to enhance the natural beauty of wood. But, they produce a strong odour and fumes that can be dangerous if inhaled during the curing process. They also require white spirit or paint thinner for cleanup. Water-based stains are less toxic and require only soap and water for cleanup. When selecting a colour, consider that light to medium tones tend to bring out the natural beauty of oak better than darker tones.
Apply the stain. Start by stirring the stain, being careful to evenly combine the particles that settle at the bottom of the can. Refer to your stain's instructions to determine if it should be applied with a brush, rag or pad applicator. Apply a thin coat using even strokes. Allow it to dry and wipe off any excess with a dust-free rag. To create a lighter colour, wipe the banister immediately after applying the stain or allow the stain to set longer to create darker tones.
Refer to the stain's instructions for recommended cure times. Once it is completely dry, apply polyurethane. Check the literature on both products to make sure they are compatible. If applying water-based polyurethane over oil-based stain, special precautions apply. After the first coat of polyurethane has dried, sand it lightly with 150-grit sandpaper, wipe it with a tack cloth and apply another coat. Apply additional coats, sanding between each coat.
The more coats of polyurethane you apply, the better-protected the banister will be.
Wear a mask and ventilate the area as much as possible to avoid inhaling fine dust particles and chemical fumes from the stripper, stain and polyurethane. Read all warnings and instructions carefully. When applying water-based polyurethane over oil-based stain, the stain needs to cure for up to 72 hours before the polyurethane can be applied. Otherwise, the fumes from the curing stain will bubble and crack the polyurethane. Check the instructions on both products for exact cure times.