Finishing

There are many options and factors to consider when finishing bowls, and a lot depends on personal preferences. One of the main determinants of what finish you use depends on whether you plan for the piece you are turning to be utilitarian or decorative. Decorative pieces may have a finish that is more surface-based and maybe glossier, whereas, on the other hand, utilitarian pieces do not want a thick finish on the outside of the piece because it can be scratched, chipped, and nicked easily; instead, you want a finish that penetrates deeply into the pores of the wood fibers to protect and seal the wood. Generally, oils make a great option for utilitarian pieces, because they penetrate and dry, while not layering up on just the surface as shellac and other lacquers might do. However, it is important to note that only certain oils are good to use for finishing. Good oils must be oils that harden and do not come from food products. An example of a bad oil would be olive oil or canola oil because they will go rancid after some time and do not cure or harden. Alternatively, oils such as linseed oil or tung oil are great options for finishing wood, as they are food-safe, hardening, and do not go rancid.

Shellac is not necessarily a bad product to use if making a utilitarian bowl, however. Shellac is a resin secreted by insects in Asia, and when mixed with alcohol, it dissolves and becomes a wood finish. The main criticism is that it does not penetrate deep enough, but this problem can be averted by diluting the shellac with denatured alcohol. This lowers the viscosity of the shellac allowing it to permeate deeper into the wood, creating a seal that can withstand water and other substances. 

Some woodturners like to apply a wax to their turnings as the last coat of finish, whether it be beeswax or carnauba wax. Both of these waxes are natural and are applied by turning the speed on your lathe very high, and then rubbing the solid wax on the spinning piece. This melts the wax on the surface of the wood, and you can then use a paper towel to rub the wax in and develop a sheen. Carnauba wax is often used as a wood polish as well if you use a three-step buffing system. A buffing system is a very easy way to achieve a high gloss on a project.