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Difference Between Polyurethane and Varnish : Complete Guide

difference between polyurethane and varnish

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If you are concerned about maintaining a long, lustrous life for your hardwood floors, fine furniture, and outdoor decking, a coat of durable natural wood finish can make all the difference.

Since poorly protected wood surfaces are unsightly and frequent refinishing is inconvenient. Thus, it is essential to learn about the difference between polyurethane and varnish. This will ensure that you are doing everything possible to preserve them.

In reality, most homeowners are faced with deciding whether to use varnish or polyurethane on their wood floors or furniture.

At first glance, these products may seem like they serve the same function and provide comparable results; however, there are vital differences between them that can affect how well they stand up to wear and tear in your home. Let’s discuss their differences.

What is Polyurethane Finish?

What is Polyurethane Finish

Polyurethane finish is a type of wood finish to protect it from damage. It’s specially designed to create a protective coating on the surface of your floors or furniture. Polyurethane finish is normally used on kitchen or bedroom furniture that requires higher durability.

This results in a very durable wood finishing that is resistant to scratches, moisture, and fading. Polyurethane finishes come in both oil-based and water-based varieties, and they can be either clear or colored.

There are two types of polyurethane such as:

Oil-Based Polyurethane

It is a synthetic alkyd resin derived from two or more components, which are mixed and then catalyzed. You can get rich color on your wood furniture by reapplying coats and oil-based polyurethane application.

Water-Based Polyurethane

Water-Based Polyurethane is a finish that can be used on wood to protect it from scratches and moisture damage. One of the main advantages of water-based is that it dries quickly.

What is Varnish?

What is Varnish

Varnish is a clear or colored wood finish applied to wooden furniture such as flooring and tables. It has a waxy texture and often helps protect the wood from moisture, staining, and scratches.

Applying Varnish by brushing on the surface of the furniture, will dry in up to 6 hours, but it is recommended to let it dry for at least 24 hours between coatings. The gloss oil-based varnish will last for about 10-20 years before it needs to be reapplied.

A variant of varnish known as spar or marine varnish offers both UV protection and flexibility. This should not be sticky when you touch it; if it does get sticky, this means that it’s too wet, which can lead to bubbles or runs.

Although these two products appear similar, they serve different purposes and produce different results depending on their use. Let us discuss the differences between these two products.

Key Difference Between Polyurethane And Varnish – Based on Basis

Key Difference Between Polyurethane And Varnish

Polyurethane vs Varnish; the main difference is Polyurethane is an oil-based finish, whereas Varnishing contains some solvents and resins.

Polyurethane finish, also known as “polyester resin,” is a synthetic resin derived from two or more components. On the other hand, Varnishing is clear or colored wood finishes for any wooden furniture.

The key differences between Polyurethane vs Varnish are:

01. Properties

Oil-based polyurethane is a very durable finish that is resistant to scratches, moisture, and fading. This is because it forms a protective coating on the surface of your floors or furniture.

Traditional Varnish doesn’t have the same level of durability as polyurethane and may not be able to resist scratches and fading as well.

02. Durability

Polyurethane is a very durable finish that can last for years. Oil-based polyurethane wood finishing will last for approximately 10-20 years before they need to be reapplied. However, they are susceptible to cracking and UV damage.

Varnishing doesn’t have the same level of durability as polyurethane.  Usually, it lasts only a few months, whereas gloss oil varnish typically lasts for about 10-20 years, but for UV protection it is better resistant. 

03. Uses

Polyurethane is normally used on indoor furniture (Wood flooring, bookshelves, desks, picture frames, hardwoods) that require higher durability.

But Varnishing can be applied on any type of wood furniture and doesn’t require the same level of preparation as polyurethane. It is more suitable for outdoor furniture like outdoor decks, chairs, boats, outdoor wooden floors, etc.

04. Gloss Level

Polyurethane has a very high gloss level, which can be restored quickly by applying oil-based polyurethane.

Varnishing doesn’t have a very high level of gloss, and it is not as easy to restore the shine.

05. Appearance

Polyurethane comes in both clear and colored varieties. You can get a rich color on your wood furniture by reapplying with oil-based polyurethane.

Varnish is available in clear varieties and helps protect the wood from moisture, staining, and scratches.

06. Drying Time

Oil-base polyurethane dries in about 2-8 hours & water-based polyurethane dries in about 1-2 hours. Traditional Varnish dries in up to 4-6 hours between coats but lets it dry for at least 24 hours.

07. Coats

Polyurethane requires 1-3 coats for maximum protection. Varnish requires several layers of coats.

08. Toxicity

Water-based Polyurethane is a less-toxic finish, whereas oil-based Polyurethane is a less-toxic finish. But Varnishing is less-toxic than Polyurethane, but it’s not recommended to use around children and pets.

09. Price

Polyurethane is a 10-20% more expensive finish as it is an oil-based product. However, it lasts longer and provides better protection.

Varnishing is less expensive than Polyurethane and is available in both gloss and matte finishes.

From the above differences, the most key differences are:

  • Polyurethane is an oil-based plastic resin with the organic solvent, while Varnish combines resins, solvents, and oils.
  • Varnish is less durable than Polyurethane.
  • Polyurethane dries quicker than traditional varnish.
  • Varnish is more expensive than polyurethane.
  • Polyurethane is more rigid than varnish, but Varnish is thinner.
  • Varnish is used outdoors, while polyurethane is used indoors.

Best Uses & Applications for Each of them

Best Uses & Applications for Each of them

There are some unique uses and applications of each of them, such as:

For Polyurethane

Polyurethane is an excellent choice for floors that see a lot of traffic, like hallways and entrances. It’s also a good option for furniture that might suffer from scratches or moisture damage, like bookshelves or desks.

Polyurethane is ideally suited to use indoors on items such as nightstands, desks, photo frames, and coat racks that have an already stunning natural color and require only a revitalizing finish.

For Varnish

Varnishing is a good choice for any type of wood furniture that you want to protect from moisture and UV rays. It’s also a good choice for outdoor furniture or decks. Varnishing will create a transparent and solid layer with a slight color.

You can use an alkyd varnish  AKA clear varnish to showcase the natural wood grain, or you can use tinted varnishing for extra protection against the sun. For optimal results, apply varnish in several layers using a natural-bristle brush.

FAQs

We will discuss some frequently asked questions that people are inquisitive about: 

01. How Do You Know When to Use Varnish or Polyurethane?

Generally speaking, you should use varnish on wood that doesn’t get much traffic or is exposed to sunlight for long periods.

02. Varnish or Polyurethane, Which One is Harder?

Polyurethane is harder and more abuse-resistant than varnish, but varnishing provides a greater degree of sheen.

03. Is Polyurethane a Good Option for Outdoor Furniture?

Polyurethane is a good option for outdoor furniture if it has the proper ingredients because it is durable and protects moisture and UV damage.

04. Does Polyurethane Come in a Gloss or Matte Finish?

Polyurethane comes in both clear and matte varieties. You can get a rich flat color on your wood furniture by reapplying water-based polyurethane.

Final Thoughts

The most important thing to remember is that varnish and polyurethane are finishes, not the wood itself. If you want to protect your furniture from scratches or moisture damage, then use a finish that will seal it in with durable protection.

Having some knowledge about the difference between polyurethane and varnish will aid you in choosing the appropriate type of finish for your home.

However, no matter what type of polyurethane or varnish oil-based or water-based you use, the main objective is to keep your wooden furniture as safe as possible.

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