How Strong is Wood Glue

How Strong is Wood Glue? (2023 Comparison)

It seems that I use wood glue on almost every project I work on these days, but how strong is wood glue exactly?

After all, you don’t want to use wood glue to bond something that needs superior strength, do you?

In this post, I’ll explore how strong wood glue is, some of the strongest wood glues, and much more. Let’s dig in!

KEY TAKEAWAYS:
Wood glue has a strength of between 2,000 and 4,000 PSI. This is considered fairly strong, and in some cases, stronger than wood, screws, and nails.

How Strong is Wood Glue Exactly?

Elmer's Wood Glue

Contrary to what you might think, wood glue is actually very strong.

Depending on the type of wood glue you use, it can even be stronger than some natural woods.

Wood glues are measured in PSI, or pounds per square inch. This measurement can be used to measure tensile strength – which is the strength is exudes when you pull it. So, if you can image, if you’ve glued two pieces of wood together and try to pull them apart, the glue with the highest PSI will require the most strength to separate.

Wood glues can range from from 2,000 to 4,000 PSI with some types being stronger than others.

Why is Wood Glue So Strong?

Wood glue is strong because of the chemical structure of the glue. Most of these glues are made of synthetic substances like polyvinyl acetate, aliphatic resin, or other chemicals that create a strong bond that lasts for years.

Is Wood Glue Stronger than Wood?

Yes! Wood glue is actually stronger than wood thanks to its intrinsic strength, in addition to the shear strength of the wood it’s bonding.

Just think, whenever you use wood glue on wood, part of it dissolves into the wood itself. Once it’s cured, not only does the wood glue provide support, but so does the wood itself. This makes the use of wood glue stronger than the natural wood on its own.

Is Wood Glue Stronger than Screws?

If you’re comparing the tensile strength of both, wood glue is stronger than screws.

When it comes to comparing the strength of wood glue vs screws, there are a few things worth considering.

First, you’ll want to consider the type of bond you’re making. For example, if you’re working with joints, using wood glue is going to give you a stronger bond than screws. However, if you’re just joining two 2x4s – screws will likely be the better choice.

You’ll also need to consider the number of screws that you’re using. As you using a single screw vs an entire board of wood that’s been coated with wood glue? Or are you using multiple screws when joining wood?

While wood glue is stronger than screws, it really comes down to ease of use. Obviously, using screws is simple if you have a power drill. Just a couple of seconds and your job is done.

With wood glue, you’ll need to clean the wood, apply the wood glue, and allow it to dry before you’re good to go.

Check out this wood glue vs liquid nails comparison to see which one is right for your project!

How Strong is Gorilla Wood Glue?

Gorilla-Wood-Glue

Gorilla Wood Glue is a strong wood glue that can deliver 3,900 to 4,000 PSI. This makes it one of the strongest wood glues you’ll find and a great option to consider for your projects.

This is one of the best wood glues for cabinets and other projects, so it’s worth keeping in stock in your woodshop!

What is the Strongest Type of Wood Glue?

Because of how critical wood glue is for many of projects, there’s no shortage of different types you can find. I’ll rank these wood glues from strongest to least strong by type.

Epoxy Wood Glue

Epoxy wood glue is one of the strongest glues you’ll find on the market. It can deliver between 3,000 and 4,000 PSI of strength.

This type of glue requires more time to dry and can also require more work to apply. Using an epoxy resin can come in handy if you need to bond wood to other materials. While it does work for wood to wood bonds, I’ve found that it’s better when bonding two different materials.

When to use epoxy glue:

  • Projects that need a very strong bond
  • Projects that bond multiple different materials
  • Outdoor projects that require more water resistance

PVA Wood Glue

PVA wood glue (also known as polyvinyl acetate glue) is the most common type of wood glue available. It comes in the brand names Elmer’s wood glue, Gorilla wood glue, and many others.

It can also deliver between 3,000 and 4,000 PSI.

PVA wood glue is a well balanced wood glue that offers superb strength, a quick drying time, and decent water resistance.

This type of glue is great for porous materials like gluing wood together and it creates a strong bond that can last for years. It’s the perfect option to glue joints of two pieces of wood.

PVA glues are also the most affordable wood glues you’ll find, so it’s a great way to save money on your woodworking projects.

When to use PVA glue:

  • Projects that need a fast dry time
  • Projects that require a relatively strong bond
  • Projects that join wood and other porous materials

Check out this video comparing multiple wood glues for more info!

Polyurethane Wood Glue

Polyurethane wood glues are another quality glue that delivers great strength and durability. The most popular brand of polyurethane glue is Gorilla Glue. These glues can deliver 3,500 to 4,000 PSI of strength.

This type of glue can be used on a variety of materials including wood, metal, stone, and more.

One huge benefit of a polyurethane glue is that it’s a more water resistant glue – which is ideal for exterior projects.

When compared to PVA glue, polyurethane glue is slightly stronger I’ve found and it’s better for exterior projects.

That said, it’s more expensive than regular wood glue and it takes longer to dry.

When to use polyurethane glues:

  • Projects that require a very strong bond
  • Projects that require more water resistance

Cyanoacrylate Glue

Cyanoacrylate glue is most well known as “Super Glue” or “Crazy Glue”. This type of glue can deliver between 2,600 and 3,600 PSI of strength.

While you can use super glue on wood, I don’t recommend it for most projects. In most circumstance, you’ll be better off using other glues like a PVA glue or polyurethane glue.

When to use cyanoacrylate glues:

  • Projects that require great strength between different surfaces
  • Smaller crafts and projects that don’t use wood

Hide Glue

Hide glue is slightly different than traditional wood glues in that it’s specifically manufactured to be less strong than others.

Hide glue delivers around 3,200 PSI of strength, but once again, this is on purpose.

Hide glue is used for projects that need a more flexible bond.

When to use hide glues:

  • Projects that require flexibility and a longer working time

How to Make Wood Glue Stronger

When using wood glue, there are a few things you can do to ensure maximum strength.

  • Clamp your wood together. Clamping your wood together will give you the maximum bond possible. Most wood glues will provide a guideline for how long you should clamp your boards together and the pressure needed.
  • Allow it to fully cure. Giving your glue time to cure is essential for a durable bond. If you start messing with your project before the glue has cured, you won’t get quite as strong of a bond which can come back to bite you later.
  • Apply in the right conditions. It’s critical to apply your wood glue under the right conditions. If it’s too humid, too hot, or too cold – you might not get as strong of a bond. Be sure to apply the glue in a relatively cool, dry location to get the best results.
  • Clean the surface before applying. Because wood glue is typically meant to bond to porous surfaces, any dust or debris between your wood joint can decrease the strength of the glue. Be sure to clean off the wood when using any glue to ensure maximum strength.
  • Remove excess glue. You might think more wood glue equals more strength. But this isn’t the case! By applying too much glue, you can actually reduce the amount of strength is exudes. If you apply too much glue, try to remove any excess with a rag and spread it out.
  • Apply glue evenly. Another easy way to increase the strength of your glue is by applying it evenly over the entire surface. If you don’t apply your glue evenly, you won’t get the maximum strength. If necessary, you might use a putty knife to smooth the glue over the entire surface.
  • Keep it out of the elements. Just as you shouldn’t apply wood glue in poor conditions, if you want it to stay strong, avoid putting it in contact with water or other elements that can cause it to break down quicker.

FAQs

Is wood glue actually stronger than wood?

Yes! Wood glue can be stronger than some natural woods. It will ultimately depend on the type of wood and glue you use, as well as how it’s applied.

How long does wood glue last?

Wood glue can last for years when bonding two pieces of wood together. Most wood glues will last for at least 3 to 5 years before it can start to breakdown, but it’s not unheard of for some glues to last for over a decade.

Is wood glue alone strong enough?

Depending on your project, wood glue can be strong enough on its own without needing screws or nails for additional strength. Because wood glue can be stronger than wood on it’s own, it can often be enough on its own.

What are the disadvantages of wood glue?

Wood glue can have a few disadvantages including the inability to use it on multiple surface types, poor water resistance, and weak end grain connections.

What happens if you don’t clamp wood glue?

When you glue wood, clamping should always be a step in the process. While it’s not technically require, if you don’t clamp wood, you won’t get the maximum strength.

What is the strongest glue to hold wood together?

The strongest glue to hold wood together is an epoxy or PVA glue. These have superior adhesion and can easily glue wood together.

What is the shelf life of wood glue?

Wood glue does expire, but it has a shelf life of around 2 years. To extend the shelf life, be sure to close the bottle immediately after using it.

How long does wood glue take to dry?

Wood glue dries in around a few hours, but it will depend on the type of glue you’re using. It can require as least 24 hours to fully cure after applied.

Final Thoughts

So, how strong is wood glue, really? It’s pretty darn strong if you ask me! In some cases, it’s even stronger than screws or natural wood.

Most wood glues deliver between 2,000 and 4,000 PSI of adhesive strength.

Wood glue can be stronger than wood and screws in some cases and it’s a great product to join wood together whether you’re making a cutting board, a butcher block counter, or any other wood project.