Hot Melt Adhesive Application and Service Specialists

What Happens When You Get Water In Your Glue And You Heat It Up!


A tub of bubbling and hot glue with water in it


Hot melt adhesives and water do not mix. When water does get into your hot melt adhesive system (either by the machine being washed down, or the adhesive becoming contaminated with water). It will cause serious problems in terms of production and most importantly staff safety.

Why Is This?

Commercial hot melt adhesives are made from a variety of materials, such as thermoplastic polymers, resins, and waxes. The specific ingredients used in an adhesive formulation depend on the intended use of the adhesive. For example, some adhesives are designed for use in high-temperature applications, while others must be able to withstand repeated freeze-thaw cycles. In general, however, most commercial hot melt adhesives contain a mixture of oil-based thermoplastic polymers, which serve as the main binding agent. Hydrophobic resins and waxes are also added to modify the adhesive properties, and additives such as fillers, cross-linking agents, and stabilisers may also be included.

Many of these petrochemical ingredients experience an adverse chemical reaction when exposed to water – e.g. through condensation, or from residues left in the tank when an operative has attempted to clean away degraded char.

Glue + Water = Trouble

When water gets into your glue, it can cause the adhesive to expand and become dangerous – creating a bubbling effect, as shown in this short video from a recent project.


When you heat up the glue, the water will evaporate in your tank, pipes, and nozzles, and that will affect the operation of your tank, eventually leading to mechanical breakdown.

The Solution?

To avoid these problems, be sure to keep your glue away from water by ensuring that there are no leaks in your storage or production area and that your staff fully understand what can and what can’t be cleaned with a jet washer!

If you do accidentally get water in your tank, the system must be drained immediately – all contaminated adhesive removed, and fresh adhesive introduced.

Finally, if you’re concerned about residues and degraded char building up in your hotmelt tank, contact a specialist cleaning contractor such as The Adhesive Laundry to perform a thorough strip down and clean. This will completely remove glue residues from your components and avoid damage, and will normally cost you less in time and money than attempting it yourself.

For a free quote or to find out more, please call +44 1480 869220 today.