Selecting Good Wood

Any tree will burn, but in general the more dense and heavy it is once air-dried, the more sun energy the wood contains. A chunk of hickory that tops 60 pounds per cubic foot will more than outlast two armloads of elm or pine, which weigh less than half as much.

An then there is "gopher wood" such as alder, aspen or cottonwood; fill the firebox and you have to turn around and "go for" another load, it burns up so quickly. Deciduous hardwoods are generally superior to evergreens as fuel and the latter also contain more volatile oils and resins. This makes them catch quickly, so pine and such make good kindling.

Except in roaring and fuel-wasting blaze, the oils burn incompletely, vaporize and then condense as pyroligneous acid on relatively cool stovepipe or flue. The black, sticky acid into creosote which must be removed frequently or it can kindle, causing a flue fire.

You should keep in mind the fact that live or green wood can contain up to 50 percent water. Fire wood should be well seasoned as explained later. If you can get green wood to burn at all you lose heat, as much energy goes into boiling off the excess water.

The steam combines with the volatiles-that's why a green wood fire smokes a lot-which only adds to the creosote problem. So don't plan to get next winter's supply of uncured wood this October.

If you want an immediate fuel supply, go looking for one or two year old downed wood that has been held up off the ground by its own limbs, other windfalls, or small standing deadwood. Swan or split ends should be gray or brown, dry unless there's been a recent rain, and will show small cracks usually radiating out from the center of the stick.

With experience you'll be able to tell good wood by its weights, hardness, speed of cutting and examination of the chips removed from the cut. A good rule of thumb is if you can get a thumbnail well into a piece of wood, it is too lightweight or too old to make a good fire. And finally, where possible, look for good wood on the high ground, away from water. Around swamps or streams you'll find willows, sycamores, cottonwoods-all light, wet wood that takes a long time to dry, then doesn't make much of a fire.