Varnish facts for kids

Varnish is a clear, hard, and protective coating. It's mostly used on wood to make it shiny and protect it from damage. Think of it like a transparent shield! Varnish is usually made from a mix of a special oil that dries, a sticky substance called a resin, and a solvent (a liquid that dissolves other things).

What is Varnish Made Of?

Varnish has three main parts:

• Drying Oil: These are oils that harden when exposed to air. They help the varnish become strong and flexible. Common drying oils include linseed oil (from flax seeds) and tung oil (from the tung tree).
• Resin: This is the part that makes the varnish hard and glossy. Resins can be natural or man-made.
• Solvent: This liquid helps dissolve the oil and resin, making the varnish thin enough to spread easily. As the varnish dries, the solvent evaporates, leaving behind the hard coating.

Types of Resins

Resins are key to how varnish works and looks. They can be natural or made in a factory.

Natural Resins

Many traditional varnishes use natural resins, which are sticky substances from plants or even insects. These resins are dissolved in a solvent to make the varnish.

• Spirit Varnish: This type uses alcohol as its solvent. It dries very quickly because alcohol evaporates fast.
• Turpentine or Petroleum-Based Varnish: These varnishes use solvents like turpentine (from pine trees) or petroleum-based liquids. They usually dry slower than spirit varnishes.

Shellac

Shellac is a very popular natural resin varnish. It's made from a sticky substance produced by tiny insects in South Asia. Shellac is dissolved in alcohol to make a varnish. It gives wood a beautiful, warm glow. However, shellac is not good for outdoor use or places where it will get wet often, like around a sink, because water can damage it.

Man-Made Resins

Today, many varnishes use man-made (synthetic) resins. These resins are designed to be very tough and durable.

• Polyurethane Varnish: This is a very common type of varnish made with synthetic resins. It's known for being extremely strong, resistant to scratches, and waterproof. You'll often find it on floors, tables, and other surfaces that get a lot of use.
• Acrylic Varnish: Made from acrylic resins, this varnish is clear, doesn't yellow over time, and is often used for art and crafts.
• Alkyd Varnish: These varnishes are durable and often used for outdoor furniture and boats because they can stand up to weather.

How Varnish is Used

Varnish is applied in thin layers, usually with a brush or spray. Each layer needs to dry before the next one is added. Once all the layers are dry, they form a hard, protective film. This film protects the material underneath from moisture, scratches, and sunlight, while also making it look better.

You can find varnish on many things around you, such as:

• Wooden furniture like tables, chairs, and cabinets
• Hardwood floors
• Musical instruments like violins and guitars
• Boats and outdoor wooden structures

Images for kids

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  Varnish on wood stairs

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  Varnished violin

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  A table green wood-stained and varnished with three layers of polyurethane varnish

See also

In Spanish: Barniz para niños