Once we understand the reality that wood moves, we can appreciate the significance of proper drying. After that, we can see the need for slow and steady air drying that flies in the face of our have-it-now culture. When quality is desired above speed, however, there is no replacement for time. Even the final step, kiln drying, takes time.
J. Gibson McIlvain is committed to taking the time to dry wood properly, offering lumber of the highest quality possible.
Step 2: Kiln Drying
After the wood acclimates to the local climate, it can be safely moved to any of our 10 kilns. Our kilns are powered in an efficient and environmentally friendly way, using a boiler heated by the offcuts and dust which we generate in our own mill.
The goal of a 6-8% moisture level for interior applications is achieved by various combinations of time and temperature, based on the species at hand. Denser woods need more time, sometimes more than a month in the kiln, while less dense woods can achieve the moisture level goal in only a couple weeks.
Special Cases
Some species require special care when it comes to kiln drying. One such species is Spanish Cedar. Growing naturally in South America and on plantations in Africa, this species is highly resinous and prone to weeping when cut. As a result, Spanish Cedar requires extremely high temperatures to set the sap and resin, preventing sticky resin stains that make finishing almost impossible.
Of course, higher temperatures create greater chances of case hardening, so it’s important to make sure the heat-up and cool-down processes are slow. The result is that Spanish Cedar needs to spend extended time in the kiln. J. Gibson McIlvain has one of the few North American kilns that can heat Spanish Cedar to its ideal drying temperature.
Sometimes, exterior species are also kiln dried, due to supply-and-demand issues. Ipe decking is one such species. Basically, the reason for its being kiln dried is not the unique benefits of kiln drying, but simply the time factor. Because kiln drying adds to the overhead expenses and price passed to the customer, ideally, exterior species are dried only to 10-18% moisture content.
The significance of the lumber-drying process cannot be overestimated. If it’s rushed, the lumber can be completely destroyed. Often, the damage done is not apparent until your project is nearly completed; the resulting frustrations and delays far outweigh the cost of waiting for proper drying to be completed.
When you take the time to understand lumber and take the right measures to ensure that movement won’t result in problems down the road, you can use lumber in almost any wet or dry state. If you’re looking for a supplier that offers a range of wet and dry lumber and takes the time to dry lumber properly, J. Gibson McIlvain can meet your lumber needs.
