Cedar posts are very popular because of their natural oils that make them less susceptible to water, rot and insect damage. However, finishing your cedar posts can make them last longer than unfinished cedar. You have many options for a cedar post finish, including simple sealing, painting, staining or a combination of staining and sealing.
Leaving your cedar unfinished is an option. Cedar contains oils that repel water, prevent rot and discourage insect infestation. However, unfinished cedar is still fairly porous. Water or other liquids can seep into the wood and stain the surface and upper layers of your posts. Although leaving your cedar unfinished is an option, selecting a good finish will help keep your posts looking good for many years.
You have many options available for staining your cedar posts. Any oil-based stain will penetrate and protect your cedar posts. However, a more eco-friendly option is newer silicone stains. Silicone stains are water-based and have good penetration to help protect your posts. Silicone stains also deposit silicone on the surface, making it shiny. Opaque stains are stains that look more like paint when applied to your posts. Although opaque stains look like paint, the surface isn't as hard as paint. However, the pigment is usually contained in an oil that penetrates the wood deeper than paints.
For best results, use an outdoor alkyd oil-based primer before painting. The primer will help create good adhesion between the post and the paint. Once primed, paint the posts with a 100 percent acrylic latex paint. Latex paint will flex with temperature changes and have a lower incidence of cracking over time. Although priming and painting your posts will make them more impervious to water, the paint is not a preservative like a stain.
If you like the natural look of your cedar posts but would like to preserve the surface, a deck sealant may work. Sealants are also good for stained cedar posts and can help create a more water-resistant surface. Because it is naturally impervious to water, staining and then sealing your posts will create the longest-lasting finish.