What is Varnish? Your Complete Guide

If you’ve carried out a few DIY projects that have a wood-centric focus, it’s likely that you’ve used or heard of varnish. But, many people don’t really understand what varnish is and how it should be used. Answering the question, what is varnish?

This can be difficult because there are many different types of wood varnish on the market. In fact, it would be fair to say that varnish has become a catch-all term for a wide variety of sealant products.

What Is Varnish Used For-a picture frame

So the varnish that you choose may be described accurately or inaccurately depending on the specific product. This can make it hard to choose the correct varnish to meet the needs of your current project. There are many general varnish terms, including shellac, lacquer, polyurethane, and more, to consider.

However, varnish is a specific product term that should not be grouped with other types of sealants. In this article, we will take a closer look at varnish to help you make an informed decision.

The Definition Of Varnish 

Varnish has been around for a very long time; it’s a slow-drying sealant that adds a protective coat when applied to wood surfaces. Varnish is composed of certain oils, resins, and solvents that are translucent, and they have a harder surface when it’s dry.

What Is Varnish Made Of? 

There are different types of wood varnish that are suited to different applications, and it’s important to choose the right one for your project. The most common type is an oil-based varnish which is resin and drying oil combined together. Many varnishes also contain various concentrations of dyes or colorants for colored finishes too.

What Does Varnish Do?

As it dries, the varnish cures into a hard and transparent film with a glossy finish. The main purpose of varnish is to protect and seal wood without detracting from the natural grain and beauty of the surface. Some varnishes are also tinted to make the wood a specific color, and this can be a viable alternative to paint.

What Is Varnish Used For? 

Varnish is designed to seal and treat wood and preserve or even improve the aesthetic qualities of wood surfaces. Wood requires treatment if it’s located in an environment where it could be exposed to potentially harmful phenomena, including abrasions, impacts, moisture, heat, and many more.

Varnish creates a chemical reaction with wood fibers; this darkens the wood and seals it against these threats to its integrity. Preventing the intrusion of insects and water into the woods can improve durability and longevity. The overall degradation may be halted, and the piece becomes more resistant to mold and rot.

Varnish repels moisture well, which makes it an ideal choice for bedside tables, coffee tables, wooden coasters, and other items that can come into contact with spilled drinking water and hot beverages.

What Is Shellac Varnish? 

A shellac varnish is formed from a resin that has been secreted from a lac bug. This substance is processed, formed into dry flakes, and then sold. Shellac can be used as a wood finish or as a brush-on colorant product. This type of varnish is best used on antiques, table tops, cabinetry, and other elegant surfaces. As an added bonus, shellac is one of the easiest varnishes to apply if you don’t have a lot of experience.

What Is Water-Based Varnish?

When you encounter waster-based products, you can understand why people ask the question: what is varnish? As we mentioned earlier, most varnishes are resin or oil-based, and a water-based alternative seems out of place in this context.

But, these are viable varnishes due to technological advances that have created acrylic resins that can be dissolved in water. They have become a popular choice, and they are just as effective as a solvent-based varnish.

More Reading: Water Based Varnish vs Oil Based Varnish – Which One Should I Use?

What Is Oil Varnish?

Again, it could be argued that an oil-based varnish is not a true varnish, although it is referred to in that manner. An oil varnish is a mix of resin and drying oil, and there is no solvent. This creates a varnish that penetrates very deeply into the wood, and the hardening process takes a long time.

What Is Insulating Varnish?

What is Varnish

Insulating varnishes like alkyds and epoxies are used to protect high-voltage components, such as generators, motors, transformers, and more, from electrical failures. A layer of electrical isolation is an effective way to prevent shorting issues.

Alkyd varnish is versatile, it can be used indoors and outdoors, and it offers good UV protection too. Alkyd dries quickly; it contains polyester resins that are modified with vegetable oil fatty acids. When this varnish is used on wood, it enhances the aesthetic qualities, dries quickly, and it’s extremely durable.

What Is Plastic Varnish?

As the name suggests, a plastic varnish is more like a coating that can be used to protect interior surfaces or to improve the resilience of existing varnished surfaces. Plastic varnish is easy to apply; it’s a plastic liquid that can be painted onto an area to improve durability and prevent scratches.

The gloss finish is tough, and it’s widely used on surfaces such as doors and windows, door and window frames, paneling, skirting, wooden furniture, and many more.

Is Wood Varnish Safe?

Traditional wood varnish products contain volatile organic chemicals (VOCs) that are not a great product for a healthy environment. The finish is exceptional, but the chemicals degrade indoor air quality (IAQ), and choosing alternative products is advisable.

The latest wood varnish products are made from sustainably produced chemicals, and they have a less dramatic environmental impact. But, all varnishes contain chemicals that should be kept away from your skin, and inhaling them is bad for your health.

When you apply a varnish, you should wear gloves, safety glasses, and an appropriate face mask. If you can, always work outdoors or in a well-ventilated room to ensure that the fumes don’t build up in the work area.

What is Varnish-In Conclusion 

As you can see, answering the question, what is varnish? can be tricky. Towards the completion of each project, you will be faced with a dilemma on the best varnish for the finish. Choosing the right protective coat for the project will have a huge impact on the aesthetic appeal and durability.

Of course, always read the varnish instructions carefully and try to match the right varnish to the project before you make a final commitment. As a final check, apply the varnish to a test piece first and check it when it’s dried fully.