You are currently viewing Is hot glue waterproof

Is hot glue waterproof

Most families have hot glue on hand for DIY projects and repairs. It always comes through, whether it’s securing embellishments, making models, or repairing broken goods. The glue’s ability to withstand water immersion is the most important test. If the glue is not waterproof, water will easily loosen the bonds it comes into touch with. However, is hot glue waterproof?

Yes, hot glue is impermeable to water. Even when submerged completely, it remains impermeable and insoluble. There are some situations where the junction will not be completely watertight, even if hot glue is known to be watertight.

Continue reading about is hot glue waterproof, to find out more about is hot glue waterproof and hot glue’s waterproofing properties. You will also learn if and why it is a good fit for your water-related project.

Hot Glue

Hot glue is a thermoplastic adhesive, often known as a hot-melt adhesive. Hot glue gun “sticks” are the most frequent form of this adhesive. Using the gun’s nozzle, the stick is heated to a liquid state and then applied.

When the glue is hot enough to burn the skin, it is sticky and will harden in a matter of seconds to a minute. Even though hot glue guns are common among hobbyists and do-it-yourselfers, they also have a variety of industrial applications.

Check Price At Amazon Check Price At Amazon Check Price At Amazon

What are the polymers used to make Hot Glue?

It is important to note why is hot glue waterproof? Polymer compounds that are not water-soluble are used to make hot glue. When a polymer compound is employed to create the oil, the glue’s properties are affected. Hot glue is made with the following polymers/compounds:


To manufacture hot-melt glue, polyamides are polymer compounds. Polyamides are utilised to firmly attach porous surfaces. Among the thermoplastics’ many advantages is the fact that they are well-suited for high-strength applications.

With their chemical stability, polymers are ideal for bonding uneven surfaces. Because polyamides are waterproof, hot glues manufactured with polyamides will also be waterproof.


In addition to polyurethane, polyethylene is utilised in the production of hot-melt adhesives. The chemical properties of the polymer make it a good candidate for producing hot glue. All glue products made with the compound are water-resistant.

Sealing trays and cartons using hot polyethylene glue is a common practice. Polyethylene adhesive is also extremely heat resistant.

EVA (Ethylene Vinyl Acetate)

Ethylene Vinyl Acetate (EVA) is a popular hot glue adhesive for glueing paper items together. When applied, the substance is water-resistant and hardens within minutes.

It takes around 10 seconds for the hot adhesive to create a solid bond between the two bonded surfaces. For the best results, Ethylene Vinyl Acetate is often paired with resins and waxes.

Additionally, the compound is well-known for its exceptional waterproofing and conditioning properties.


Metallocene adhesives, like polyethylene adhesives, have excellent thermal characteristics. This light-coloured tape is mostly used to seal trays and containers.

Metallocene’s outstanding char-free qualities also enable machines that break down frequently due to undesirable carbon accumulations to minimise maintenance activities.

Paper, cardboard, fabric and children’s artworks are all examples of permeable lightweight materials that can be glued using this hot glue.

Amorphous Poly Alpha Olefins.

Adhesives with lengthy set periods, such as APAO adhesives, can be used in applications requiring long exposure times. In product assembly, the impermeable and soft textures of these glues make them perfect.

They are often mixed with synthetic resins to improve the adhesion properties of Poly Alpha Olefins. APAO adhesives are also used in paper packaging and diaper manufacturing industries.

Is hot glue waterproof

Can hot glue stand pressure application?

It is a great glue since it can withstand a lot of stress. Even though it is not flexible, it is a fantastic adhesive and works in a way that allows you to put weight on the items that are attached.

It would be possible to glue two pieces of wood together and then compress them with an anvil, and the glue would still function and hold the planks together thereafter.

Because the sealant between the planks would break down under the weight of an anvil if it had been allowed to harden and cured before being placed under an anvil, the planks would fall loose.

Surface material bonding effects on the hot glue

Because of its capacity to adhere to both porous and non-porous surfaces, hot glue is a standout among adhesives. EVA-based hot glue can’t be expected to perform well in high-stress situations.

Look into high-performance polyolefin, polyamide, acrylic, or polyethylene hot glues from your hot glue supplier like Amazon, these may be available (PE, PEMA, PEnBA).

Even more polymers than the ones listed above can be blended into one product by some producers that provide unique blending options. There are many hot glues available that are suitable for various types of materials (such as wood and plastic), but their distinct qualities make them all behave differently when immersed or exposed to water.

Hot glue’s water resistance on wood

Wood is one of the most vulnerable building materials to water damage. Wood is a porous, hydrophilic material. What this implies is that if you don’t seal the wood, it will soak up water and get bloated over time. Expect the hardwood hot-glued section to be non-water resistant due to this additional stress.

Hot glue applied to plastics is water-resistant.

A hot-glued plastic object should not be submerged in water for an extended period. If this is a water-related project, such as a model boat or the like, it is not going to work. Only a brief immersion in room-temperature water would be necessary.

Because the plastic bits are so little, the hot glue binding them to other surfaces like wood, glass, metal, or cloth would compress and appear to let go of the bond over time if exposed to water.

Hot glue applied to glass is impervious to water.

Amorphous solids, such as glass, are common in nature. In addition, glass is often a nonporous material. When heated, the glass will expand and contract. This is similar to how hot glue and other thermoplastics expand and contract.

Glass is a poor conductor of heat, therefore it can maintain temperatures in its own body for long periods of time. Even so, it is still preferable to wood and certain plastics. If the hot glue bond is exposed regularly, it may deteriorate and eventually fail. If the glass is immersed underwater, this is even more critical.

Resistance to water from hot-glue-coated fabrics

Generally, woven and non-woven fabrics are characterised as such when the fabric is comprised of yarn or fibres bonded together. When it comes to hot glue adhesion, both of these types of materials are excellent choices. Woven fabrics, on the other hand, allow hot glue to be used to cover practically any surface.

Do You Use Hot Glue as a Sealant?

Now that you know that is hot glue waterproof! Is hot glue a good sealer if it is waterproof and can survive a variety of weathering conditions, such as rain? Many aspects must be taken into account, but the majority of the time the answer is no.

The fact that it is difficult to work with after application is the primary reason it is not an ideal sealer. When a sealant is not the right fit, there are a variety of additional options. However, once the hot glue is out, you only have a few seconds to fine-tune it before it loses its effectiveness.

Application of hot glue with gun

To protect an area from a wide range of water and chemicals, the sealant must be applied thoroughly. This includes long-term exposure to solvents.

Even if the sealant itself is unaffected, the materials to which it is attached may be. Water and damp air will seep in if the glue seal wears away or breaks down. Another reason why hot glue is not the best sealer is that after it is applied, it loses a lot of its flexibility.

Sealants often need to move and bend a little in order to avoid causing cracks. It is possible for hot glue to harden, causing it to separate from other components or to break.

best hot glue gun waterproofuniverse best hot glue gun waterproofuniverse best hot glue gun waterproofuniverse
Check Price At Amazon Check Price At Amazon Check Price At Amazon

Is hot glue able to hold underwater?

When heated to a proper temperature, all hot glues will melt and then solidify either when cooled or when pressure is applied.

If you think about it another way, when the hot glue is heated it expands into a molten state, but then compresses to its original volume when the adhesive bond is made. Thermoplasticity is the term used to describe this feature. It is because of this feature that hot glues are so useful. It is, however, the Achilles’ heel of hot glue when it comes into contact with moisture.

When hot glue is exposed to water, the temperature drops rapidly, resulting in the glue contracting farther than its sticky condition. Cracks, holes, or even very small seams might form in the hot bonded joint as a result of this. Water travelling over an object’s surface quickly breaks the hot glue joint, allowing it to disintegrate over time.

Is it safe to use hot glue on projects that will be outside?

Plastics are the primary constituents of hot glue, as was previously stated. As a result, ordinary hot glue is prone to deterioration by ultraviolet light. However, is hot glue waterproof for outside projects Hot glues, with the exception of those based on polyethylene (PE, PEMA, and PEnBA), are severely degraded by ultraviolet light?

However, the ultraviolet rays aren’t the only danger that hot-glued things face when they are left outside. Temperatures can fluctuate wildly during a typical day and night. In particular, if the adhesive object is exposed to direct sunshine.

Due to temperature expansion and contraction, any small break that may have formed would have been exacerbated by the wind’s tiny dust particles. This isn’t a problem if the project is small enough that you only need to show it out once in a while. The cheapest hot glue doesn’t work at all.

It’s best to avoid using a hot-glued object for long periods outside, especially if the hot-glued joint is subjected to additional tensile stress, such as when it’s attached to a wall or post.

Gorilla Original, Waterproof Polyurethane Glue

Whenever the glue is exposed to moisture, it begins to foam, creating a filling effect. The open working time of Gorilla Glue is 20 minutes. When cured, the glue turns a tan colour and is completely impermeable.

Pressure-treated wood is no match for the tensile strength of Gorilla Glue. Stone, metal, ceramics, foam, glass, leather and more can all be bonded with Gorilla Glue. After drying, the product can be sanded, stained, painted, and varnished.

Is hot glue waterproof

Frequently Asked Questions

Question: Is hot glue a good adhesive for glass?

Answer: To better attach jewellery, you’ll want jewellery-specific hot glue instead of regular household variety. When attaching heavy glass objects, a normal glue stick’s bond may weaken with time. Heavy glass can be glued with specialised glue sticks developed for heavy-duty tasks.

Question: How can you strengthen hot glue?

Answer: You may reinforce an adhesive bond by providing your bonding surfaces a little ‘teeth,’ as I explain in my adhesive tutorials. Smooth surfaces should be sanded down to a rough texture before using hot glue to ensure the glue has something to cling onto.

Question: Is hot glue a long-term fix?

Answer: Hot melt glue forms a long-lasting adhesive when cooled to a temperature below its melting point. Hot glue, on the other hand, is as long-lasting as epoxy and can be used in situations where epoxy can’t.

Question: What happens when you put crayons in a hot glue gun?

Answer: Crayons melt in the hot melt glue gun, releasing a rainbow of colours you may utilise in your artwork. Using a glue gun, just squirt, drip, and paint molten wax into the canvas using the crayons. Due to the lower melting temperature of crayons compared to glue, they are more easily injected into the gun.

Conclusion about Is hot glue waterproof

In general, is hot glue waterproof? With a huge asterisk, hot glue is waterproof. This means that water would not pass through if we applied an even layer of hot glue on top of a surface and then sprayed it. Clamping may be necessary to hold the project in place until the glue has dried fully before it can be considered sturdy.

Leave a Reply