All wood is usable as firewood. Driftwood contains too much salt, as a result of which stoves rust and when chlorine gas is released, dioxin is formed. In the past, it was often soaked in rainwater for 2 to 3 years to wash out the salt as much as possible. In North America there are species that produce toxic gases, such as the rare Poison Sumac and the Manchineel.

You don’t just split wood to get it in to the stove, but especially to dry it faster, so it will less be moldy and rot. A round full trunk dries too slowly. Trees have their outer bark mainly developed to prevent drying out. Cleaving increases the evaporation surface area substantially.
Resinous wood dries more slowly and may need five years to dry before you use it.

Wood heats. Dragging wood from the forest uses approx. 1,168 kcal / h (running 1,213), cleaving with an ax uses 444 (cross-country skiing 405). A day work with the chainsaw will cost you approx. 6,000 kcal.

Harvesting and processing wood is winter work. The ground is firmly frozen, the wood contains as little as possible wet, and there are (almost) no mosquitoes.

If you are felling out trees that already carry leaves, you use leaf drying. Leave the tree as a whole. The leaves continue to function as long as possible and use juice from the wood. As a result, the moisture content quickly decreases from 50 to 35%. Don’t process further until the leaves are dry.

You can also speed up the drying process by removing the protective bark (or some strips).

Bark retains evaporation and moisture, that's why we split it. When stacking, lay the bottom layers with the bark down, the top (rain protection) with the bark upwards.

Fresh wood has a moisture content of about 35%. The ideal humidity level is around 15%. Firewood should be as dry as possible, which gives the highest yield. You rarely get drier than 12%. (The wooden door style in the house still contains (at least) 8% moisture.) In trade, 'dry' for firewood means that it contains up to 20% moisture. So a 1 kilo wood block contains another 200 grams of water that has to be evaporated as smoke. Such a block weighs half of a block with 60% moisture! Dry wood is therefore also considerably lighter. Half of the weight of fresh wood is water. A wood pile must therefore evaporate hundreds of liters, so that the blocks also shrink and get cracks. In good conditions, your wood can get dry in a few months.

A kilo of 'fully' dry wood would deliver 5.32kWh of energy, regardless of the type of wood. With 20% moisture, 4.2 kWh remains. Because not all energy can be used in a combustion-related manner, in practice it is 3.2 kWh.

The wood type is less important. The least energy-rich type of wood (hornbeam) contains only 10% less energy per kilogram than the most energy-rich (larch). Yet there is a difference between so-called hardwood and resinous (soft) wood. The latter category (pine, fir, birch, pallet timber, ...) is less suitable for most stoves. During the combustion, resins are released that evaporate. An average stove cannot completely burn these gases. You get more tar deposits in your chimney and a big risk of chimney fire. Warm-accumulating stoves or mass stoves such as soapstone or tile stoves burn more efficiently.

Fresh splits better. Let it not dry first. Saw from the lower (widest) part of the trunk a straigt block of about 50 cm high (knee-high), then you have a good chopping block to set up the other stem parts. The wider your splitting block, the much stronger and more stable it is. An additional advantage is that you can put a tire, to place in there the block you want to cleave Then it is not falling apart, and keep all the pieces neatly upright. Even if they were not cut straigt. Smaller pieces you keep upright too to stab multiple in the tire. The tire is a solid, third hand so it made two free hands to cleave with full power. You can also use an elastic luggage strap (like the luggage rack on the car or bicycle) that may be extended, and adaptable with a piece of chain).
klievenAs kindling you use prunings and deadwood (and pine cones, , at least the one from here…. In Australia there are melon-sized specimens that can weigh up to 11 kilos!).

Pruned twigs that you want to use as kindling can best be mixed. Some species easily ignite, others much more difficult. Bark often ignites less quickly than wood: think of the protective effect against fire and drying out of cork oak. Also cleave splinters you can keep. Would you still chop kindle, use a piece of wood to hold the block. Your fingers are too valuable to take risks.

Consider the knots in the wood, which are not to split. Work in between. Wood without knots you can often split in one stroke with an ax or maul.

Hold the ax high, right above your head. Further back, or askew makes no sense and wasts your energy. Set high you use the full weight of the falling ax. Provide a rapid blow, preferably in a pre-existing crack. If you double the speed of the ax, the strength is quadrupled. The hitting ax remains perfectly vertical. The more inclined he comes down on the block, the more energy you lose. Ideally, the shaft at the touch is horizontal. Otherwise, your block stands too high or too low to use the advantage of all the power.
If you don’t blow at once through it, then lift ax with block together, turn it in the air and let the back of the ax come down on the chopping block. To lift a heavier block keep it closer to your body.

Why lift a heavy log to split? You can also hit the ax again in the wood?
Right. Except as the ax is stuck, and you have to pry it loose first. But also if you want to be sure that your ax strikes exactly the same spot each time.

You can also blow the ax with a hammer through the woods. A real maul is heavy, and made ​​to beech behind with a hammer.
Move a stuck ax from the top down until it comes loose. Not wring sideways from left to right, because the handle may break.

You can wet and freeze a stubborn log. The next day in the morning it will be easy to cleave.

A leather, rubber or rope occupancy around the shaft just near the blade protects the shaft.
Respect the existing sharpening angle and grind both sides equaly to maintain the shape. Axes (and cutting tools) can be grinded better by hand than electric, because the temperature of the cut becomes too high and the original curing (already from 200C) is lost.

Carry the ax with the handle, the ax-head with the cut down.
Regularly check that the blade is firmly seated on the handle.

For heavy or gnarled pieces you use more loose wedges and a hammer. They stay in the same place, while it is very difficult with an ax just to chop each time exact the same place. Blow the chisel in a radius from bark to center, possibly in an existing crack, in the cross-cut (sawn, flat) side. Try to focus between the knots of branches. And just keep ramming. Make sure you have 2 or 3 bits, in case one gets stuck. A hatchet is sometimes useful to bite the last persistent fibers.

Experience is like a toothpick, no one wants to use yours.