Hot knife rope cutters are handy to have stashed with your tool kit essentials – whether you love a crafty DIY project or professionally work in a trade. Hot knife rope cutters can be used for many different purposes, beyond just cutting synthetic ropes and bungee cords. 

However, it is important to know how to safely and accurately use a hot knife rope cutter before jumping straight in. Keep reading as we guide you through how to use a hot knife rope cutter the right way so that you can confidently use this versatile tool – whatever the task. 

What is a hot knife rope cutter?

A hot knife rope cutter is an electric tool with a heated blade, used to cut, shape or seal synthetic materials. This tool is far different from regular blades and rope cutters, as the heated mechanism can cut through and seal material far more easily and smoother, preventing loose ends, unravelling and fraying.  

Why should you use a hot knife rope cutter?

Hot knife rope cutters have a wide range of benefits for various applications. 

1. Prevent fraying and unwinding

Hot knife rope cutters can provide clean and precise cuts, compared to regular blades or scissors, which maintain the integrity of the material by preventing it from fraying or unwinding. This is because the heated mechanism seals the synthetic fibres together when cut, rather than leaving them loose. This is particularly useful for both industrial and crafting purposes. 

2. Saves time and effort

Hot knife rope cutters provide a more streamlined operation to cutting synthetic fibre. Instead of having to cut, repair and seal separately, the hot knife rope cutter streamlines all these tasks into one swipe – compared to other traditional methods. 

3. Multi-use and versatile

Whilst the name may suggest hot knife rope cutters can only be used on synthetic ropes, this is not the case. Hot knife rope cutters can be used to cut through various other synthetic materials, such as bungee cords, upholstery, carpets and clothing, making this an extremely valuable and versatile addition to your toolkit. 

Uses for a hot knife rope cutter

Hot knife cutters cut through synthetic materials by melting and sealing them as they pass through. This includes all synthetic materials, such as polyester, acrylic, dacron and nylon. 

You can use hot knife rope cutters across many industrial, design, manufacturing and trade industries, as well as in household and craft projects. Hot knife applications can include:

• Cutting and sealing rope, cord and bungee cords
• Rubber processing
• Manufacturing mould die-casts and extruded parts
• Rubber coating and adhesive removal
• Wire stripping
• Electrical installations
• Cutting and designing upholstery 
• Carpet fitting 
• Sealing packages
• Art, design and architecture 
• Door and window manufacturing
• Model making

Hot knife rope cutters cannot be used on natural materials, like leather, cotton and wool, as they do not melt and will instead char and burn on the heated blade. They cannot be used on metal either, as the blade does not get hot enough to melt through it, and could therefore cause substantial damage to the hot knife rope cutter. 

How to stay safe when using a hot knife rope cutter 

Whilst hot knife rope cutters can be used both at home and professionally, safety should always be paramount, as with any tool. 

Create a safe working environment  

When using a hot knife rope cutter, you should first protect yourself by wearing safety equipment and working in a safe environment. This includes:

• Working in a well-ventilated workspace
• Keeping children and animals away from the area
• Working away from water sources
• Having a fire extinguisher on hand 
• Wearing heat-resistant gloves
• Wearing fire-resistant clothing 
• Wearing safety glasses 

Safety considerations before using a hot knife rope cutter 

1. Only use the hot knife rope cutter on synthetic materials 

A hot knife rope cutter is only intended to be used on synthetic materials. Read the material label carefully before using it, ensuring there are no blended natural materials or metal elements. 

2. Monitor the temperature of the hot knife rope cutter 

By design, the hot knife rope cutter will get very hot when in use and remain hot for a period of time afterwards. Allow sufficient time for the blade to cool and keep it away from flammable materials. Never touch the blade when it is hot. 

H3. Check the cable and plug before and after use

Before using, check that the power cable and plug are completely intact. Do not use it if it is damaged in any way. After using, always ensure that the power socket is unplugged – as well as when removing or installing the cutting blade. 

4. Use as instructed 

Follow the instructions on how to use your hot knife rope cutter safely and effectively. Do not use two rope cutters simultaneously, as this can cause a short circuit. Do not use the hot knife rope cutter on wet material or in the presence of water. Only use the tools and accessories supplied. 

How to use a hot knife rope cutter

Step 1: Install the blade 

When installing the blade, ensure that there is no power going to the hot knife rope cutter and that it is unplugged at the power socket. Using the Allen key, turn the nuts on the blade apron anti-clockwise and insert the two legs of the cutting blade into the apron. Then, using the Allen key, turn the blades clockwise to secure – do not over-tighten. 

The blade will not heat if the cutting blade is not securely in place. If this is the case, unplug and try again. 

Step 2: Prepare to cut

Preparing to cut your material is a very important step. Make sure that whatever surface you are cutting on, you place a glass sheet underneath to prevent the surface and the material from being permanently damaged. Depending on your confidence, you can also always use a prop to help support your cutting, such as a metal ruler or yardstick. 

Step 3: Cut your intended material 

Now is finally the time to cut your intended synthetic material with your hot knife rope cutter. Hold the rope cutter as you would a pen or pencil, adjust the temperature to your desired setting and then press and hold the trigger switch to heat the blade. Place the blade on the material, and in a back-and-forth motion with even pressure, cut through the material. Do not pause the blade on the material. 

If you find that the temperature is not sufficient enough to cut the material, readjust and try again. Make sure to avoid the blade burning red hot, and do not hold the trigger switch at maximum temperature for longer than 15 seconds at a time. Do not apply excessive force when cutting, or the blade may become warped.

Top tip to make using a hot knife rope cutter easier

Some people find that when they cut rope or cord with a hot knife, the end unravels, melts and turns into a mushroom/blob shape. This can make the material unusable, especially if you’re wanting to thread it through hooks or shock rings. 

Instead, wrap some masking tape around the material where you want to cut the line. When you cut, the tape will keep all the strands together so that they consistently melt together and do not unravel. 

When it comes to everything about bungee cords, you can trust that we know a thing or two. Head over to our super helpful Bungee Store blog to learn more, or contact our friendly team for expert advice!