The Resination of Logs

 Are your logs bleeding? Many plants secrete an oozing pitch, also known as resin. This hydrocarbon component is not necessarily the same compound as 'sap,' which refers to the lifeblood fluid of a plant that transports water and nutrients. Resins do not carry nutrients like sap does, but they can provide other benefits to the plant to aid in its defense. Log home owners, especially of homes built from coniferous trees, may experience the frustration of pitch oozing from their logs creating some unsightly gobs on the wood.

Dripping resins often occur on warm days when the heat of the sun warms the pitch in the wood and they flow out of the wood in an increasingly liquid state. Pitch drippings are no destructive to log homes; in contrast, the presence of resins in the wood are actually beneficial to their preservation. Homeowners may find the dripping pitch to be an eyesore, however, and seek ways to remove it.

Clean-up of pitch drips is fairly simple: large, congealed gobs can be scraped off with a putty knife or similar tool. Residual traces of the pitch can be cleaned off with denatured alcohol, also known as methylated spirits. What isn't simple is the fact that some logs, especially if cut in the summer, may seem to have an unending amount of resin contained in them. Many people have sought a product that can be applied over knots and cracks to lock the bleeding in, but periodic cleaning is the only effective treatment.

Other than the recurring drips of fluid pitch coming from logs, there are also great benefits of beauty in tree resins. Resins have historically been an important ingredient in creating varnishes and many log home finishes, and resins like frankincense and myrrh have historic, therapeutic value as essential oils. Petrified, hardened pieces of resin are known as amber and used in jewelry. The ancient insects found captured in amber is a good reminder that resin is valuable in defending wood against its predators. So while scraping off those gobs of coniferous pitch, remember that it does have a purpose; even if it gives a few side-effect headaches along the way.

by John E. Schroeder

More information on plant resins:
 "Plant Resins: Chemistry, evolution, ecology, and ethnobotany", by Jean Langenheim, Timber Press, Portland, OR. 2003