Cedar is a type of wood that encompasses a variety of species, including Spanish Cedar, Eastern Cedar, Juniper and the aromatic Red Cedar. The advantages of cedar is that it is much more weather-resistant than other varieties of commonly-available lumber, making it ideally suited for use in outdoor woodworking projects such as benches or window boxes.
Cedar has some limitations, but those limitations could also be looked at as strengths. For instance, some finishing methods are ideally suited to cedar, but paint is not one of them. Of course, cedar is richly grained, so why would one want to paint over the grain?
Woodworking with Cedar:
Although cedar works well for projects outside, where it will be subjected to the elements, it isn't the most stable of species. Cedar will tend to have a lot of expansion and contraction depending on the season. Keep this in mind when designing or building a project.
Wood glues work well on cedar, but mechanical fasteners such as nails and screws tend to work themselves out over time due to the seasonal movement of the wood. Stainless steel bolts, with nuts and washers would be a better choice for mechanical fasteners (where appropriate).
Cedar is also naturally insect and rot resistant, and although it does move a lot seasonally, it typically doesn't splinter much over time. Since it is naturally water-resistant, it doesn't require any treatment before being used outside, and when allowed to weather naturally, cedar will develop a unique grayish-color. These properties make it a perfect choice for garden projects such as raised planter beds or window boxes.
A number of aromatic cedar varieties are available, particularly Spanish Cedar (typically from South America). This type of cedar has a very distinct scent, one that is appealing to most humans, but very unappealing to insects. For many years, people have lined closets and chests with aromatic cedar to keep moths and other insects out of their clothing. This is where the old term "cedar chest" originated, as people would store their winter blankets in cedar boxes, knowing that insects would avoid the aromatic wood.
Over time, the distinct scent of aromatic cedar can fade, as the exposed faces become oxidized, reducing the amount of scent that is exposed. A good way to "rejuvenate" old aromatic cedar is to simply give it a light sanding with some fine sandpaper. Be sure to wipe down the surface completely after sanding to avoid getting fine sawdust on your clothing and blankets, but you'll be surprised at how quickly the scent returns.
Most varieties of cedar are vividly grained, with a variety of colors depending on the sub-species. If you choose to apply a finish to your cedar woodworking project to prevent the natural graying of the wood, there are a few things to keep in mind.
First of all, as mentioned above, you should probably avoid painting cedar. Other than the fact that you're covering up the grain of the wood, paint simply doesn't adhere well to cedar over the long haul. While it will look fine initially, eventually the paint will begin to flake and peel, and you'll have to scrape and re-paint every couple of years.
Stain is a much better choice for cedar, because it will allow the wood to breathe (where paint will seal the wood). A quality stain with some UV protection in the color of your choice will help keep the project looking great over time, even with repeated exposure to weather. You may need to re-stain the project every few years, but you won't need to scrape and sand as you would with paint.