When strolling down the wood finishes aisle in your local hardware store, you may be overwhelmed by all the choices you have: Interior or exterior? Oil-based or water-based? Polyurethane or tung oil? The options seem endless. While it would be great if there was just one finish suitable for every situation, unfortunately, it's not quite that easy. The good news, though, is that there are a number of great finishing products available -- and they're pretty simple to apply.
1. Polyurethane Varnish
The most popular finish for do-it-yourselfers today, most polyurethane varnish is oil-based, which simply means the product contains mineral spirits. When using oil-based products, whether it be a stain or a finish like polyurethane, make sure to have ample ventilation: strong fumes will be emitted from both the can and the wood itself as the mineral spirits evaporate.
Tips for Polyurethane:
- Always stir well -- the ingredients tend to settle.
- Apply with a natural-bristle brush, foam brush, or lambswool applicator.
- Use only on interior surfaces: tables, cabinets, bookcases, floors, furniture, etc. Polyurethane won't withstand exposure to the elements.
2. Water-Based Protective Finishes
If you're sensitive to the fumes from mineral spirits, consider a water-based protective finish. This product is a good choice for time-sensitive projects, since it dries considerably quicker than polyurethane. Though it appears milky-white in the can, the finish will be perfectly clear when applied.
Tips for Water-Based Finishes:
- Apply with a synthetic-bristle brush for best results.
- Best used for interior furniture: cabinets, tables, etc. Unless the can specifically recommends it, it's not well-suited for use on floors (unlike polyurethane).
- Clean up with soap and water.
3. Oil-Based Spar Urethane
If your project will be used outdoors -- or will be exposed to excessive moisture or sunlight, such as a windowsill or bathroom vanity -- an oil-based spar urethane is the right finish choice. The can should identify it as being designed for outdoor projects; exterior urethanes have special additives that reflect the sun's ultraviolet rays before they start to break down the finish.
Tips for Oil-Based Spar Urethane:
- Apply with a natural-bristle brush.
- Ideal for windowsills, vanities and outdoor furniture.
4. Lacquer
When a short drying time is a priority, lacquer finishes are often the best bet. Like oil-based and water-based finishes, lacquer also dries on top of the wood -- generally, in just a matter of minutes, making it ideal for furniture and craft projects.
Tips for Lacquer Finishes:
- Apply with a brush or spray can.
- Avoid using on surfaces that will be subjected to lots of wear and tear, like floors -- lacquer doesn't have the strength of polyurethane.
- Ideal for small furnishings and craft projects.
5. Tung and Danish Oil, Wipe-On Polyurethane
Finishes 1 through 4 are known as "surface finishes": they build layer upon layer of finish on top of the wood. While surface finishes provide great protection, they don't appear completely natural. For projects that call for a subtle, almost-not-there finish, select a penetrating oil: tung oil, Danish oil -- or a wipe-on polyurethane. These oils are thinner than surface finishes, allowing them to sink into the wood rather than drying on top of it.
Tips for Wipe-On Polyurethane Finishes:
- Apply with a clean, soft cloth -- no brushes required. Simply work the finish into the wood until it's all been absorbed. The finish will dry inside the pores of the wood, protecting it against spills, but leaving a natural appearance.
- Ideal for intricate spindles, craft projects and furniture touch ups.
