Hot glue is a staple for many DIY projects and other small applications. You might have already used it or be tempted to try it for future applications.
Well, if you’re still unsure whether this adhesive would make the right choice, you’ve come to the right place! In this article, I’ll cover everything to do with hot glue.
Once you learn about how hot glue works and its advantages and downsides, you’ll be able to make an informed decision.
While this adhesive is great from many points of view, no glue is perfect for every project.
So, let’s learn more about hot glue— what it is, how it works, its strong suits, how to get the best out of it, and more!
Also, check out my comparison guide on hot glue vs. super glue.
What Is Hot Glue?
Hot glue is a bit different from other adhesives on the market. It’s a type of plastic that acts like an adhesive.
You might often see it described as a “thermoplastic adhesive”.
Instead of curing through a chemical reaction like most other glues, hot glue cures through heat loss (hence the “thermo” part in its name).
As the glue cools down, it solidifies into its original state.
Its main ingredients in hot glue include ethylene-vinyl acetate, polyamides and polyesters, polyethylene, ethylene-methyl acrylate, styrene block copolymers, polyolefins, and ethylene n-butyl acrylate.
No special ingredients increase adherence, nor do any special curing agents.
Unlike other glues, hot glue is solid, usually coming in the form of cylindrical sticks. You need high heat to melt and dispense it.
Then, once applied, the melted glue cools down and solidifies again, forming a bond between the glued surfaces.
History of Hot Glue
Hot glue is simple enough to formulate, given that it’s made from synthetic polymers.
And such plastics have been around since the late 19th century. However, it wasn’t until the latter half of the 20th century that the first glue gun was invented.
In 1941, Carl E. Weller patented the first transformer-based soldering gun, which could heat and cool down rapidly.
Building upon this foundation, in 1954, a man named George Schultz invented the first industrial glue-heating gun, which would first be used in shoe-making.
This efficient glue heating and dispensing system quickly became popular with the general public.
And as demand grew, more variations and improved versions of the glue gun appeared throughout the following decades.
How It Works
As stated before, hot glue works very differently from other adhesives. Hot glue is solid at room temperature and must be melted before use.
Regular glues can be used straight out of the tube and cured through chemical reactions.
To use hot glue, you first need a glue gun to melt the glue sticks. The glue gun is also helpful for dispensing the glue quickly and with great control.
All you have to do is pull the trigger and watch the melted plastic flow.
Hot glue doesn’t “cure” in the traditional sense of the word. It doesn’t lose any moisture because it isn’t water-based.
Moisture and UV exposure also doesn’t trigger any chain reaction because there’s no curing agent.
Check out my guide on UV glue for more info.
Instead, hot glue goes through a simple physical reaction. As the plastic cools down, it solidifies to its original state.
When the plastic is completely cooled, you get a hard, somewhat flexible material that keeps the surfaces glued together.
There are also different methods you can use to remove hot glue.
How It Cures
In theory, hot glue doesn’t go through a curing process. That’s because curing is a chemical reaction between different agents.
When it comes to hot glue, no chemical reaction occurs when the adhesive is exposed to oxygen, moisture, or UV light.
There’s no moisture loss and no curing agent involved in the formulation of hot glue.
However, most online articles about hot glue and product labels will mention curing times.
That’s to keep things simple because most people use the words “curing” and “solidifying” interchangeably.
But realistically, hot glue goes through a heating and cooling process without any chemical reaction for proper curing.
The temperature changes that hot glue goes through are reversible. Also, hot glue doesn’t undergo any irreversible chemical changes because it returns to the same structure when cooled.
Hot Glue Strength
Hot glue is affordable, quick, and convenient and works on many materials.
However, this shouldn’t be your top choice when it comes to strength. I should mention that the adhesive itself is sturdy and difficult to break.
However, the bond it creates, although decent, isn’t the best you could get.
Hot glue can handle a decent amount of weight, up to 700 pounds. However, its bond has poor resistance to shock, impact, tension, and high heat.
Don’t rely on hot glue for heavy-weight applications or long-lasting repairs.
You could easily break apart any hot glue bond if you exposed it to tension or impact.
Hot Glue Uses
It might be disappointing that hot glue isn’t as strong as other adhesives. However, it can still be great for other types of applications.
Let’s see the areas where this adhesive truly shines and gives you its best performance.
Compatible Materials
Hot glue can bond to virtually any material as long as it has a porous surface.
It can still stick to smoother materials, as long as there’s at least some texture for it to grab onto.
However, if the materials you’re working with are completely smooth, the hot glue will peel right off once cooled.
When it comes to specific materials, you can use hot glue on wood, wood composites, foam, stone, construction paper, cardboard, fabric, most plastic with a textured surface, certain types of glass, and more.
You won’t get hot glue to stick to smooth materials such as metal, vinyl, silicone, or very smooth plastics.
You might have some luck if you prep the surfaces first. Lightly sanding metal and other smooth materials will create some texture for the glue to bond to.
On the same note, materials must always be clean and dry because hot glue doesn’t adhere well to greasy or wet surfaces.
Check out my guide on removing hot glue from fabric for more tips.
Recommended Applications
Hot glue might not be the strongest or most durable, but it still makes an excellent choice for small tasks.
It’s rather flexible, has good water resistance, and is non-toxic once dry.
You can use it for various lightweight projects, including arts and crafts, clothing decorations, small repairs around the house, light woodworking, and more.
Because it’s non-toxic, this adhesive is also food-contact safe and pet and child-safe.
However, there’s still a danger of painful burns if your skin accidentally comes into contact with hot glue.
Because of this, children should only be using this adhesive under adult supervision.
Advantages of Hot Glue
Sometimes you just work on small-scale, lightweight projects and can’t decide what adhesive to use.
Many types of glue could give you the same results. In that case, it’s important to weigh the pros and cons of each glue.
When it comes to hot glue, there are some considerable advantages.
First, hot glue is very affordable. Most hot glue stick packs come with at least 20 pieces, which could last you for a long while.
There are also value packs that offer you a great bang for your buck.
Then, there’s also the fact that hot glue has a very long shelf life. You won’t have to deal with glue drying out or clogging the dispenser.
Hot glue keeps well when stored properly. You only use what you need and save the rest for later applications. There’s little if any, waste going on.
Hot glue is non-toxic. It doesn’t go through a curing process, so there are no volatile organic compounds to worry about.
Because it has a high melting point and contains no harmful components, it’s also less of an environmental concern when it comes to disposal.
It’s very easy to use. The glue gun offers you great control over how much product you’re using.
You’re also less likely to get the glue all over your hands. Hot glue also dries and solidifies very quickly, so there’s little waiting time involved.
Hot glue has great moisture and solvent resistance and dries somewhat flexibly.
This makes it great for textile applications where other glues could stiffen the material or wash off when exposed to water.
Last but not least, hot glue is also tintable. You can mix any color with it and get the desired shade.
This is especially handy for arts and crafts because you can match your glue to any color and get a subtle result.
Downsides Of Hot Glue
There are many great advantages to using hot glue. However, we should also cover the downsides.
You need to be aware of where hot glue falls short, so you can decide whether it is a good option.
These disadvantages shouldn’t be a dealbreaker, but it all depends on what you need from your application.
Requires Additional Equipment
While most glues can be straight out of the tube, hot glue requires a hot glue gun. Without one, you won’t be able to melt and apply the adhesive.
Luckily, there are hot glue guns for all price ranges, so you can always find an affordable option.
Non-porous Surfaces
Again, hot glue works best on porous surfaces—the more textured the material you use, the better.
Hot glue will bond somewhat with slightly smooth materials, but it will peel right off of completely non-porous surfaces.
If you need to bond porous and non-porous materials together, you might want to opt for glue that can adhere to both types of surfaces.
You can also try to prep the smooth surfaces before using hot glue.
Heat Resistance
Hot glue has poor resistance to heat. If you think about it, it makes sense.
Hot glue must be exposed to high temperatures to melt and become usable. But it can always melt again, even after solidifying.
This is a concern if you’re using low-temperature glue sticks because these can turn liquid at just 176°F.
However, most hot glues are applied after reaching a temperature of around 320°F.
Still, just because hot glue doesn’t turn completely runny doesn’t mean its bond can’t lose strength when exposed to higher temperatures.
Impact Resistance
Hot glue doesn’t have the best impact resistance. While it does dry rather flexibly, it can’t resist shock, tension, or flexion.
Also, hot glue can bear a decent amount of weight, but it’s still not powerful enough to offer structural integrity.
Hot glue bonds break apart easily if exposed to repeated tension, impact, or flexion, so don’t rely on hot glue for heavy-weight applications or moving components.
Messy Application
In theory, hot glue is easier to apply than other glues. You’ll never get your hands dirty because the glue gun does all the work for you with the press of a button.
However, it’s still difficult to control how much glue gets dispensed.
You have to get used to the glue gun, which takes a bit of experience. You can still end up with a messy working space.
You might use more glue than you intended, and the adhesive could drip where you don’t want it.
Luckily, cleaning up hot glue is a quick and easy process.
Hot Glue Removal
Sometimes, hot glue can still get on your hands and clothes. It might also drip and fall on the floor, your working table, or other surfaces where you don’t want it.
Luckily, you can do a few easy things to get rid of it.
Remember that hot glue has poor resistance to high temperatures. If there are any stubborn glue leftovers you can’t get rid of, apply heat to the area.
You can use a blow dryer to soften the glue. Once the bond becomes loose, you can scrape the glue off.
You can also apply to rubbing alcohol onto the soiled area. This will also loosen the bond and make the glue easier to remove.
Finally, the glue might stick to a smooth surface in the best-case scenario. In this situation, you won’t need anything special.
Because hot glue has poor adherence to non-porous surfaces, you can wait for the adhesive to dry and then peel or scrape it off.
Any putty knife will do the job just fine.
Popular Brands
There are plenty of hot glue brands on the market. But not every one of them offers the same quality.
If you’re unsure what to pick, you could consider the following brands. These are well-known for producing high-quality, high-performance hot glues.
Gorilla Glue is probably the best-known brand of adhesives out there. They produce different sizes for both mini and full-sized glue guns.
You can choose between 4” and 8” glue sticks and packs ranging from 10 to 75 pieces.
Artellius is another great brand. Their value packs come with 200 glue sticks a piece, and the 4” size is perfect for mini glue guns.
Surebonder offers a great option for low temp glue guns. Their glue sticks come in 4” and 10” sizes and have a lower melting point than regular glue sticks.
You can buy their glue sticks in packs ranging from 15 to 100 pieces.
Ad-Tech offers 4” and 10” size glue sticks in packs ranging from 24-50 pieces. These work great for multi-temp glue guns.
Lastly, Ewparts has glue stick packs of 11, 50, and 75 pieces. What’s cool about these glue sticks is that they come in up to 15 colors.
These are great for art and craft projects because you don’t have to tint or paint them yourself.
Wrap-up
Hopefully, you found this article informative.
After covering the theoretical details, the applications, the advantages, and the disadvantages of hot glue, you should be able to decide if this adhesive is best suited for your projects or not.
The most important thing to remember is that hot glue works best for textured surfaces and lightweight applications.
Keeping these details in mind, you can complete many different tasks using this kind of glue.