Wine barrels are constructed from some of the finest woods available, so it is a logical, not to mention eco-friendly, step to find alternative uses for them after their life in the winery is finished. For years, people have been using wine barrels in their homes to create a cosmopolitan feel to a kitchen or foyer, or to add a conversation piece to a wine cellar or home bar. Outdoors, wine barrels can be used to collect rainwater, or can be cut in half vertically or horizontally to make clever containers for your patio plants. Whatever purpose you find for your barrel, it will look much better with a coat of varnish.
Wash away any debris, using a scrub brush and detergent. If the barrel has any signs of mold or mildew, use bleach, water and a scrub brush to remove. Finish by using plain water to completely remove any detergent or bleach and let dry completely, preferably in the sun.
Check the barrel on the inside and outside for any minor imperfections, such as nail holes or scratches. Fill in any gaps with a wood filler that will accept a stain, if you will be staining your barrel. Check the label to make certain that it will work with a stain. Don't allow the wood filler to run over the top of the hole you are filling. Let the filler dry completely, then sand it down with 120-grit sandpaper to the level of the rest of the wood.
Score some grain marks into the wood filler with a razor blade. Place these marks in the filler in the same direction as the wood, and try to mimic the grain marks that surround the wood filler.
Sand the entire barrel down, inside and out, using 120 grit paper. This will open the pores of the wood up to accept the stain or varnish. Finish with a final sanding of 220-grit paper. Rub the surfaces down with a rag to remove any dust.
Stain or varnish the barrel, using a rag to apply the stain. If you are not using a stain, apply varnish only with a paintbrush.