Tar

Tar is a dark, thick liquid.

It can be made from wood, coal, or oil.

To make it, people heat wood in a special oven. This heat makes the tar drip out. It leaves behind charcoal.

Long ago, people used it on wooden boats. It helps keep the wood from rotting. It also keeps water out.

Some people use it on roofs. It can even be used in food. It is used to flavor candy.

Tar has a very strong smell. It is a very useful thing.

Tar is a thick, dark liquid. It can be dark brown or black. People make it from many things. They use wood, coal, or oil. One way to make it is through destructive distillation. This is a way of heating organic matter to break it down.

To make wood tar, people use a kiln. A kiln is a special oven. They stack small pieces of wood inside. They cover the wood with earth and moss. This keeps air out so the wood does not catch fire. Then, they light a fire on top. After a few hours, the tar drips out. This leaves behind charcoal.

People have used tar for a very long time. In the past, it helped protect wooden ships from rot. It also kept water out of sails.

Today, it is still used on wooden boats and old roofs. It can even be used in food. Some candies and drinks use it for flavor. Tar can also be used in medicine. It can help with skin issues. But be careful. Some types of tar, like coal tar, can be toxic.

Tar is a thick and sticky liquid. It is usually dark brown or black in color. Scientists call it a viscous liquid of hydrocarbons and free carbon. You can make it from many different organic materials. These include things like wood, coal, and peat. It can also come from petroleum. People use a method called destructive distillation to make it. This means heating the material to break it down.

Making wood tar is a very specific way of working. People often use a special oven called a tar kiln. First, they split pine wood into small pieces. They stack the wood very tightly inside the kiln. Then, they cover the wood with moss and earth. This is important because it keeps oxygen out. If oxygen gets in, the wood might catch fire. After that, a fire is lit on top of the kiln. The tar slowly drips out of an outlet hole.

People have used tar for thousands of years. In ancient Greece, people knew how to make wood tar. In Scandinavia, it was used since the Iron Age. For a long time, it was a huge part of the economy. Sweden was a major exporter of tar for many centuries. In 1615, they sent 13,000 barrels of tar to other places. By the year 1863, they sent 227,000 barrels. The Royal Navy in the United Kingdom was a very large user.

Tar has many different jobs in our world. In the past, it helped protect wooden ships from rotting. It also kept sails waterproof. Today, we still use it on old wooden roofs and boats. Some tar is even used in food and medicine. In Finland, people use tar water to flavor candy and alcohol. It is also used in some shampoos and cosmetics. However, some types like coal tar are dangerous. Coal tar contains benzene and is listed as a dangerous good.

You might see tar in places you already know. For example, the La Brea Tar Pits in Los Angeles are famous. These pits contain naturally occurring asphalt. Some people call this mineral tar or mineral pitch. In Canada, there are places called tar sands. These are made of asphalt found in Alberta. You can even make a tar-like substance at home. If you heat corn stalks in a microwave, you get tar. This process is called pyrolysis.

Tar is a dark brown or black viscous liquid. A viscous liquid is a substance that is thick and flows slowly. Tar is made of hydrocarbons and free carbon. These are chemical building blocks found in many organic materials. People obtain tar through a process called destructive distillation. This process involves heating organic matter to break it down into different parts. Tar can come from many sources like wood, coal, peat, or petroleum.

The process of destructive distillation works by using heat to change a material. When wood is heated this way, tar and pitch drip away from the wood. This leaves behind a solid material called charcoal. If you use deciduous tree woods, the process produces methanol and charcoal instead. Methanol is also known as wood alcohol. For certain materials like corn stalks, you can use a microwave to perform a similar process. This specific method of heating is called pyrolysis.

There are different types of these thick substances. Scientists often use the terms "tar" and "pitch" to describe them. People sometimes use these words interchangeably, but they have subtle differences. Tar is generally more fluid or liquid. Its thickness depends on where it came from and the temperature. Pitch tends to be more solid or viscoelastic. A viscoelastic substance behaves like both a liquid and a solid. Natural asphalt is a type of pitch that some call mineral tar.

Making wood tar is an ancient craft with a long history. People in ancient Greece knew how to produce it. In Scandinavia, it has likely been made since the Iron Age. For many centuries, wood tar was a vital part of the economy in Northern Europe. Sweden was a major exporter of tar for hundreds of years. In 1615, Sweden exported 13,000 barrels of tar. By 1863, that number grew to 227,000 barrels. The Royal Navy of the United Kingdom was one of the largest users of this material.

To produce wood tar, people traditionally used tar kilns. These are special ovens used for dry distillation. In Scandinavia, kilns were built near forests using limestone or holes in the ground. The bottom of a kiln is sloped toward an outlet hole. This allows the liquid tar to pour out. First, workers split pine wood into small pieces. They stack the wood very densely inside the kiln. Then, they cover the wood tightly with earth and moss. This prevents oxygen from entering the kiln. If oxygen enters, the wood might catch fire and ruin the batch. A fire is then lit on top of the kiln. The tar begins to pour out after a few hours and can continue for days.

Tar has many important uses in different industries. For millennia, wood tar was used to waterproof sails and wooden ships. It helped protect the wood from rotting. Today, it is still used to seal traditional wooden boats and historic church roofs. It is also used to paint the exterior walls of log buildings. In Finland, wood tar has a place in medicine because it is microbicidal. This means it can kill microbes like bacteria. People use tar water as a scent in saunas or as a flavoring in candy and alcohol. It is also used in cosmetics and anti-dandruff shampoos.

Some forms of tar are much more dangerous than wood tar. Coal tar and petroleum tar are considered toxic and carcinogenic. A carcinogen is something that can cause cancer. This is because these tars have a high benzene content. Because of this, coal tar is listed as number 1999 on the United Nations list of dangerous goods. However, in very low concentrations, coal tar is used as a medicine for skin conditions like psoriasis. In history, tar was also used for public punishment. This was called "tarring and feathering." A person would have hot wood tar poured on their skin and then feathers were attached to it.

Finally, tar is connected to many different parts of our natural world. You can find naturally occurring pitch in places like the La Brea Tar Pits in Los Angeles. In Alberta, Canada, there are large areas called tar sands. These are made of asphalt found in the ground. Even the term "Rangoon tar" refers to a specific form of petroleum. Whether it is found in the earth or made in a kiln, tar remains a very important material in human history and science.