Yes, glue expires.
The following main factors influence the shelf life of a glue:
- The type of glue
- The ingredients used to formulate the glue
- The storing conditions of the glue
- How often is the glue used (therefore exposed to air, moisture, water vapor, or humidity)
Different types of glue have varying chemical formulations, determining when the glue expires. Some glue types expire after 6 months once you open them; while sealed, some last up to 3 years.
Typically the shelf life of wet craft products, such as spray adhesives and liquid glue, is about 1-2 years after they have been opened.
Adhesives made with more natural ingredients have a much shorter shelf life.
If you want to discover more about when different types of glue expire, whether you can still use expired glue, or how to extend the shelf life of your glue, keep reading.
Types Of Glue: When They Expire
Often, glues are placed into categories based on how they work, how they have been applied, or their formulations.
Generally, these are the categories:
- Natural
- These adhesives are made with natural ingredients
- Also known as bioadhesives as only organic sources are used in the formulations of these glues
- One-part
- The one-part types of glue require a chemical reaction to be activated
- These adhesives start drying and curing when they come in contact with sources such as heat, water vapor, moisture, or humidity
- Multi-part
- The most commonly known glue that is a multi-part is epoxy glue – the resin and the hardener parts come separately, and they need to be mixed
- As you mix the different parts, these create a polymer cross-link through a chemical reaction
- Anaerobic
- This type of glue works in the absence of oxygen
- These are commonly used to stick metals or other materials to metals
- Synthetic
- These adhesives contain synthetic materials such as elastomers, thermoplastics, and emulsions
- Contact
- Contact glue is used for the tough attachments that need to withstand tear
- Pressure-sensitive
- These types of adhesives need pressure applied so they can form a strong bond
- This pressure is either applied by the hand, clamps, hooks, ropes, tape, or other creative tools
- Drying
- These adhesives can be dried to cause them to harden to the surface
- Hot
- They melt when heat is applied and harden as they cool down, such as hot glue guns
Now let’s look at the shelf life of glues.
This likely won’t come as a surprise, but different glues have different shelf lives.
The shelf life of the glue depends mainly on its components or the ingredients used to formulate and create the adhesive.
Here are the general shelf life of some well-known glues:
- Cyanoacrylate Glue
- Shelf life sealed: about 1 year
- Shelf life after opening: about 2 months
- PVA Glue
- Shelf life sealed: about 2-3 years
- Shelf life after opening: about 6 – 12 months
- Polyurethane Glue
- Shelf life sealed: about 1 – 2 years
- Shelf life after opening: about 12 months
- Wood Glue
- Wood glue can last up to 3 years when stored in optimal conditions
- Super Glue
- Shelf life sealed: about 12 – 15 months
- Shelf life after opening: about 6 – 12 months
- Epoxy Glue
- When stored in ideal conditions and kept sealed, epoxy glue can last as long as 15 years
- Nail Glue
- When unopened, the shelf life of nail glue is typically 12 months if stored in optimum conditions
- White and Yellow Glue
- These typically have a shelf life of 2 years when unopened and stored properly
- Eyelash Glue
- Shelf life sealed: about 1 – 6 months
- Shelf life after opening: about 1 month
How To Extend The Shelf Life Of Glue
How you store your glue plays a role in shortening or lengthening the adhesive’s shelf life.
Here are the Dos and Don’ts on how to store glue if you want to protect and even extend the shelf life of your glue.
- Store the glue in a dry and cool place, away from humidity and moisture
- Most glue reacts to moisture and humidity, such as cyanoacrylate and polyurethane
- Even the smallest amount of moisture, water vapor, or humidity can cause the glue to start drying
- Don’t open the glue container if you won’t use it
- An opened glue container has a much shorter shelf life than one that is kept sealed
- Only open your glue container when you are about to use it
- Always keep the bottle sealed tight
- This will prevent the air from getting in the container and causing the glue to dry
- Store your glue in a place where UV light doesn’t reach it
- UV light can lead to the degradation of some adhesives
- Don’t store the glue in direct sunlight
- Store your glue container away from heat sources, including direct sunlight or various heating tools
- Thermoplastic types of glue react to heat
- Polymer adhesives respond to higher temperatures
- Most glues have a longer shelf life when kept in cooler conditions
- Keep the glue container in a Ziplock bag
- This will keep moisture and humidity from getting in the container and affecting the shelf life of the glue
- Add a dry silica pack to the bag
- This will absorb the humidity or moisture present in the air
- Wipe down the nozzles of the containers after each use to enable to cap to seal properly
Can You Use Expired Glue?
So what happens to the glue that you forgot about or didn’t get to use multiple times, and by the time you wanted to use it again, you realized that it had expired?
Is there anything you can do with expired glue?
We don’t recommend working with expired glue for the following several reasons.
- Expired glue isn’t as strong and effective in creating a lasting bond
- Some adhesives become moldy, which could pose several health risks
- Expired glue could potentially negatively affect or even fully destroy equipment or various materials
- Discoloration
- Inability to stick properly
- Loss in effectiveness
When you want (or need) to use glue, you need to get two or multiple surfaces to bond together and stay that way.
Expired glue cannot offer that. It cannot bond the surfaces with the same strength, becoming ineffective and useless.
Frequently Asked Questions
Can you use moldy glue?
You shouldn’t use moldy glue for the following reasons:
- Ineffective bonding
- Health concerns caused by mold
Can you revive expired glue?
Once the glue has expired, you cannot make it usable again. It loses its stickiness and adhesion properties.
How to know that wood glue has gone bad or expired?
Wood glue should pour well. If the viscosity level has dropped and it is very difficult to pour and use, this most likely indicates that the glue has gone bad.
If the glue has become very thick and doesn’t stick well, or if it changes color, these are indications of glue gone bad.
What is glue viscosity?
Glue viscosity comes in three varieties: high, medium, and low, and it refers to adhesives fluidity.
A glue with high viscosity has a thick consistency (like a cream or gel), and a medium viscosity glue is fluid and best for porous and uneven surfaces. In contrast, a low-viscosity glue is very fluid, runs easily, and is best for flat surfaces.
How to know if nail glue has aged or expired?
Nail glue becomes thicker as it ages, and it will become less runny. The shelf life of nail glue is 12 months when unopened.
How do you know if the glue is expired?
If you notice the following signs, your glue is most likely expired:
- Yellowing or discoloration of the glue
- The glue has become thicker or rubbery
- The glue has dried completely
- The glue lost its stickiness
- It doesn’t bond properly
Does wood glue go bad if frozen?
Wood glue will become less and less effective each time it gets frozen.
Does Titebond wood glue go bad?
Yes, you will know that Titebond wood glue has gone bad when it becomes thick and stringy or if its color has become orange.
Does wood glue get weaker over time?
Wood glue does not get weaker over time if it is stored properly.
Conclusion
Glue does expire, some sooner than others.
If you have expired glue containers, you may still want to use them, so they don’t go to waste, but here is why you shouldn’t.
Expired glue is much less effective. It won’t form a strong (or a lasting) bond.
