Disadvantages of air seasoning of timber? (2023)

What are the disadvantages of air drying timber?

The main disadvantage of air drying is that all pieces of a given stack of timber will not necessarily dry to the same moisture content. Boards on the inside of the stack may have completely different moisture content to those on the outside.

State two advantages and two disadvantages of Air / Natural Seasoning. Advantages: Inexpensive, Easily managed, No specialist labour required, No expensive equipment needed. Disadvantages: Slow, No control over final MC, MC of only 18% achievable, Weather dependent, Boards prone to fungus/insect attack.

Seasoning improves the strength and stiffness of timber and reduces the tendency to break, snap or warp.

Some wood suppliers prefer air drying because the process dries out the logs evenly with minimal cracking and no internal tensions baked into the wood. A major advantage of air-dried logs is that the logs retain their natural color better than kiln-dried logs.

On top of breakage, air-drying can also increase frizz, build-up, and mildew, especially for afro-textured and curly hair. "Hair that stays wet or damp for a long period can attract bacteria and fungus, especially if you have very dense hair," explains Jennie Roberts, a celebrity hairstylist, and texture hair educator.

“The longer your hair stays wet, the more the cortex of your hair will swell and break, resulting in brittle ends and lots of flyaways.” A 2011 study supports that assertion. It found that, though hair dried with increasing levels of heat showed surface damage, hair that was air-dried showed more damage to its cortex.

A defect of seasoning, where the surface of the wood dries faster than the core. This cases permanent stresses and 'set' (deformation) that are released when the wood is cut, resulting in severe distortion. A longitudinal crack that does not go through the whole log or plank; usually caused by too-rapid seasoning.

MOISTURE AND HUMIDITY

The relative humidity of the surrounding air, therefore, is a very im- portant factor in the seasoning of wood, and a general understanding of the relationship between humidity and drying is essential in any consideration of seasoning problems.

How long does it take to air seasoning wood?

Eventually, the wood will reach a moisture content that is in equilibrium with the surrounding ambient air and humidity. While a 1-inch red oak board may take two to three months to air-dry, a 2-inch board may take six to eight months, and even thicker lumber may take years.

Artificial Kiln Seasoning of Wood

Kiln drying of lumber is perhaps the most effective and economical method available. Drying rates in a kiln can be carefully controlled and defect losses reduced to a minimum.

Air-dried logs are less expensive, up to 20% less, then kiln-dried since the substantial investment and the high cost of running the kiln is eliminated. Kiln-drying is the most effective way of ridding logs and timbers of mold, mildew and insect infestation.

By drying our clothes outside we keep them fresh and well aired. This avoids moisture being trapped in the fibres encouraging musty smells that are always unpleasant. Putting clothes away clean and aired will enhance the life of any garment over time, which means your favourites remain your favourites for longer!

Drying your clothing on a tumble dry or air dry setting can help keep clothes from shrinking by minimizing wear to the fabric fibers. Your clothing's care tag will provide the optimal temperature and dryer settings to help avoid shrinkage.

It's environmentally friendly.

For many households, the clothes dryer is the second-most energy-consuming appliance, right after the refrigerator. However, by simply switching from using a clothes dryer to air-drying your clothes after washing them, you could reduce your home's carbon footprint 2,400 pounds a year.

Air-drying is easier on fabrics

Using a machine dryer wears clothes fast, thanks to the increase in friction and heat. Washing your clothes and then drying them on a clothes drying rack or outdoor clothesline minimizes that impact.

Air Transport carries certain disadvantages too and they are: (i) Cost of operating airlines is very high and so freight cost is very high as compared to sea transport. (ii) It is difficult to carry bulky, awkwardly shaped goods. (iii) Very risky in case of accident.

What is the main disadvantage of air journey?

High cost – It is considered as one of the most important disadvantages because air transport is a very costly service because of its too high price of operational costs.

Long-term health effects from air pollution include heart disease, lung cancer, and respiratory diseases such as emphysema. Air pollution can also cause long-term damage to people's nerves, brain, kidneys, liver, and other organs. Some scientists suspect air pollutants cause birth defects.

Knots. As one of the most common defects in timber, knots occur when branches die off and the bases become enclosed by a second layer of wood.

In artificial seasoning, the drying is fast and uniform. Therefore, defects in timber such as shrinkage, cracks and wrapping are minimum. Moisture content in wood can be reduced to the desired level due to the artificial seasoning. So the chances of fungi and insect attacks are less.

These negative impacts include: destruction of forest cover, loss of biodiversity, ecological imbalance, soil compaction, soil erosion, flooding, desert encroachment and disruption of hydrological cycle.

Air circulation is maintained between logs because it helps to reduce moisture which is important for seasoning. The environment for this need to maintain some conditions. A clean, shady, dry, cool place is preferred. Sometimes logs are coated by an impermeable substance to reduce extreme moisture.

The drying rate is controlled by three factors: temperature, relative humidity and the rate of air circulation.

(i) Air seasoning or natural seasoning.

As soon as possible after felling, the log is converted by sawing it into battens and planks etc. These are then stacked on a well drained place in the shade. While stacking care should be taken to ensure free circulation of fresh air all around each piece (Fig. 9.22).

How can you tell if wood is seasoned enough?

To identify well-seasoned wood, check the ends of the logs. If they are dark in colour and cracked, they are dry. Dry seasoned wood is lighter in weight than wet wood and makes a hollow sound when hitting two pieces together. If there is any green colour visible or bark is hard to peel, the log is not yet dry.

As long as your wood is seasoning properly and you don't need to burn it right away, there's no harm in waiting two, three or even four years. (After four years, the wood may start to decay.) By waiting longer, the moisture level in the wood will continue dropping, making it even more efficient to burn.

If you want to build out of 2x4s, build out of 2x4s! Your best bet is to just get it as dry as you can. So the first option is to get a moisture meter. The next option is to let the lumber sit inside for four-eight weeks to air dry.

There are many ways of seasoning or drying timber, but only two methods have been found satisfactory, principally for economic reasons. They are air drying and kiln drying.

There are two main ways of seasoning timber. the first is the natural method where the timber drys naturally by air. The second is kiln drying, where the wood is circulated and the temperature of the wood is controlled by a kiln.

Seasoning Your Firewood

You should leave your wood exposed to air and sunlight while allowing it to properly season, but once it's dry, it should be covered. You should not pack unseasoned firewood into a tight space or shed to dry.

A con to building with air dry clay is how fragile it can be. Thin additions like legs, fingers, and ears will easily break off. To avoid small parts breaking off, have students create mixed media pieces.

Cracking is normal in air dry clays: it's caused by shrinkage because of the loss of the water inside the clay body. Cracking in air dry clay is typically caused by sculpting over an armature or using a lot of water, either to mix the clay or to help it adhere onto a previous layer.

If stored properly, unused air dry clay should last indefinitely. We recommend wrapping the unused clay in plastic wrap or in a Ziploc bag, and then in another airtight container.

Air dried lumber is a hand tool woodworkers best friend, it's easy to work and is more stable than kiln dried lumber because it's not forced dried through high temperatures, but rather a natural slower process.

What is the moisture content of air dried lumber?

Air-Drying Lumber

Properly stacked lumber will dry to about 15 to 20 percent moisture content. The time it takes lumber to air-dry depends upon climatic conditions (temperature, relative humidity, and air movement or wind), wood species, lumber thickness, and piling method.

Several studies have shown that appropriate use of paper towels or jet air dryers decreases the number of bacteria in washed hands (12–14).

Drying clothes on a low heat setting or air drying can prevent damage and keep clothes from fading.

Air-dried logs are less expensive, up to 20% less, then kiln-dried since the substantial investment and the high cost of running the kiln is eliminated. Kiln-drying is the most effective way of ridding logs and timbers of mold, mildew and insect infestation.

Most timbers are prone to pest, rot, mold and fungi attacks, some are far better than others but they both require a minimum of LOSP or ACQ treatments for outdoor structures. Timbers tend to silver or look old if left natural and unpainted. Timber maintenance can seem to be higher than other building materials.

Timber is hydroscopic, meaning that it absorbs water. Some preservatives can increase timber's ability to attract and absorb moisture. When timber absorbs moisture, the piece of timber will increase in dimension by up to 5% across the grain and 0.1% along the length. Drying will cause the opposite effect.

Drawbacks of hot air drying include degradation in nutrients and flavor, shrinkage, fractures and case hardening, color darkening, and decrease of antioxidant and rehydration capacity due to prolonged exposure to high air temperatures.

Drying your clothing on a tumble dry or air dry setting can help keep clothes from shrinking by minimizing wear to the fabric fibers. Your clothing's care tag will provide the optimal temperature and dryer settings to help avoid shrinkage.

If a product is made before the shrinkage takes place damage to joints can occur and the product will fail. If the shrinkage is not excessive, the wood may warp even though the joints may not break.

How long does it take to air dry timber?

Eventually, the wood will reach a moisture content that is in equilibrium with the surrounding ambient air and humidity. While a 1-inch red oak board may take two to three months to air-dry, a 2-inch board may take six to eight months, and even thicker lumber may take years.

Some timber may need to be replaced after a few months of exposure where other parts may be sufficient for use after 12 months of exposure. Where timber has 20% or more of moisture content for prolonged periods of time, fungal degradation or decay may be present, especially in untreated timber.

In order to be usable for a construction project, wood must be kiln or air-dried to a moisture level of 19%. But wood that is intended for indoor use— that is, wood intended to be used for woodworking— must have a moisture content level that is less than half that amount, at only 9%.

The acceptable moisture levels of wood and lumber are in the range of 6% to 8% for interior and 9% to 14% for exterior wood or for building envelope components within constructed assemblies.