Wood Finishes

     Varnishes are a combination of a vegetable oil and a resin. Soy, linseed, tung, safflower, oiticica, and perilla oil are examples of these oils, although tung and linseed are the most comonly used varieties. The three most commonly used resins are phenolic, alkyd and the popular urethane. The oil used affects the color of the varnish, while the resin used primarily affects the durability of the varnish. Varnish works as a result of polymerization (making longer chains of the same short molecule) these varnishes change from a liquid to a solid, a process which strengthens the finish. However the resins in varnish allow for a more durable finish compared with oil alone. The phenolic types are incredibly water resistant, and have good UV and grease resistance. They are useful for exterior furniture to prevent damage from the elements. The alkyd ones are less expensive have good abrasion resistance and moderate moisture resistance. These are useful for interior finishing. The polyurethane varieties dry and cure faster and are more scratch, heat and moisture resistant, but aren't very affective against UV damage. 
     Linseed oil and tung oil are called "true oils." These pure oils cure similarly to varnish, by the process of polymerization. Tung oil is more moisture resistant and is aler in color than linseed oil. To apply these true oils, simply wipe them on the wooden surface and let the oils seep in and polymerize to a hardened surface. Make sure to wipe off the excess oil with a clean dry rag.  A combination of varnish and oil (mostly oil with a touch of varnish: each manufacturer uses varying ratios) are known as teak oil, danish oil, and other varieties. These offer the benefits of both the true oil and varnish, thus they are recomended for wooden furniture care and maintenance. Click here to purchase our teak oil
     Shellac comes from secretions from a tropical bug in Asia.  It dries faster than varnish, but isnt as durable and not as useful in large projects.  Most shellac in a can contains wax, which lowers water resistance and prevents some other finishes from bonding to it. You can varnish on top of shellacs that contain NO wax for added protection. For ones that do contain wax, the polyurethane varnish won't stick well. If the shellac is sticky after it has dried (15 minutes) then that batch of shellac has gone bad. 
     Waxes are generally not recomended if used alone. They can be used on top of other finishes like varnish for polishing but are not sufficient alone. Furthremore, if applied to liberally to the wooden surface, they can attract dust and over time leave a grimy feel and look.