What you need to know about storing shock cords

Shock cords are a staple in countless commercial, industrial and recreational applications, as their unique combination of elasticity and strength makes them ideal for securing, bundling and restraining items in dynamic environments.

However, it can be easy to underestimate exactly how much the performance and lifespan of a shock cord can depend significantly on how it is stored. Poor storage practices degrade the cord’s elasticity, weaken the sheathing or core, and reduce its reliability when used under tension, so it is worth making sure that you and your team are taking a proactive approach to storage – enabling you to have peace of mind in a shock cord that remains safe, effective, and reliable.

Where do shock cords need to be stored?

Shock cords need to be kept in a clean, dry, and well-ventilated area, away from direct sunlight. This is because ultraviolet (UV) exposure deteriorates the synthetic materials commonly used in commercial-grade cords, weakening the sheath and accelerating failure. It is generally advisable to store the shock cords on metal shelving or sealed bins, as this can helps keep them off concrete floors, which tend to absorb moisture and cause mildew or rot.

Indoor storage areas should ideally be insulated and temperature controlled, as stable ambient conditions reduce the chance of thermal stress and help maintain the elasticity of both the outer braid and inner core. The cords also need to be placed well away from heating ducts, windows or active chemical use. Vapours from fuels, oils or solvents can degrade both the elastic and the outer fibres, which can potentially lead to brittle spots or surface pitting.

We would recommend racks, drawers or wall-mounted reels to help with storage, as these can help to maintain cord shape, prevent tangling, and give your team quick access without the risk of placing stress on specific sections of the cord.

How can temperature and humidity affect your shock cords?

Essentially, temperature extremes create stress in the materials used in shock cords. Exposure to high temperatures can softens the core, and potentially even permanently deform the elastic, while excessively low temperatures can make the material brittle and increase the risk of snapping. There is also the issue of repeated temperature cycling, whereby the temperature changes from warm to cool and back again repeatedly – especially in poorly insulated storage units. This effectively shortens the usable life of cords.

High humidity is another crucial consideration, as high levels cause condensation, particularly in unsealed packaging or storage near external walls. That prolonged dampness can lead to mould growth, especially in sheaths made with cotton or blended fibres. Equally, mildew introduces organic decay, which weakens the sheath and causes delamination between layers.

In commercial settings, it is highly advisable to use thermostats and dehumidifiers to maintain stable conditions between 10°C and 25°C with relative humidity around 40–60%. This range effectively helps preserve the structure and performance of the cord over long-term storage.

What packaging is best for protecting shock cords?

In keeping with what we have discussed above, shock cords benefit from packaging that protects against light, moisture and physical abrasion. For small quantities, resealable polyethylene bags or vacuum pouches can provide reliable protection, and as a bonus they are easy to store in drawers or bins. For larger coils or industrial reels, you can use plastic wrap combined with a rigid box or tub to prevent crushing and contamination from dust and grime.

It is also a good idea to ensure that plastic containers include breathable desiccant packs in areas where condensation may form. When cords are stored on reels, ideally all team members should be aware that the tension needs to remain neutral (not stretched or tightly wound) to protect the core.

Every package must display a manufacture date or batch label to support stock rotation. You can also use clear storage instructions to ensure that they are properly handled, such as ‘Keep cool’ or ‘Do not stack’.

Key signs of poor storage

Some signs of poor storage are fairly obvious, and spotting them early can be helpful in preventing degraded cords from entering use. One early indicator is also one of the most obvious – namely, a drop in elasticity. When a cord no longer retracts as expected or feels soft, that could indicate that the core requires replacement. Equally, noticeable surface changes such as bleaching, cracking or hardening can suggest UV exposure or contact with chemicals.

Mould is generally not difficult to spot, as it appears as speckles or patches and produces a musty smell. This always needs to be a major priority, as any fungal growth can damage the cord’s sheath and weakens the internal structure. Surface stickiness often develops from chemical breakdown of outer polymers caused by heat or contaminants.

Rust, pitting or staining on metal end fittings indicates moisture exposure that compromises hardware. Always ensure that your team checks:

• Elasticity and rebound force
• Colour consistency and surface texture
• Fraying, cracking or residue on the sheath
• Smells, stains or soft spots suggesting microbial or chemical deterioration

If your or your team spot any of these symptoms, you may need to make a judgement call as to how fit the cord still is to perform its duties. If you are lucky, you may be able to identify and rectify the problem before any permanent damage comes to the cord. However, if you are ever in doubt, generally it is better not to take the risk of a potentially damaged cord entering active service.

5 common mistakes with shock cord storage

Many issues in shock cord performance can be traced back to overlooked storage habits. In busy warehouses, workshops or transport settings, these habits often go unnoticed until problems arise. This is why it is generally a good idea to have regular routine inspections, so that the integrity of your cords is not fully dependent on simply relying on someone to check them.

The following is a quick recap of some of the most frequent errors, many of which we have covered above.

• Storing the cords in direct sunlight. UV radiation eventually breaks down the sheath and core materials, which leads to fading, splitting and loss of elasticity.
• Leaving cords tightly coiled under tension. Continuous pressure from tight coils stresses the internal fibres of the cords, which reduces their rebound strength and durability.
• Using open or non-sealed packaging. Airborne dust, moisture and fungal spores can all compromise the materials if they go too long unchecked.
• Mixing used and new cords. Cross-contamination from older stock can be a major cause of inconsistent performance, and complicate quality control – which is particularly problematic in safety-critical applications.
• Ignoring temperature and humidity control. Environmental stress can break down elastic cores and sheathing layers, which again can make the cord unreliable or unsafe to use.

These are all the essential points covered – and if you ever need any help or more specific advice on the storage or usage of your shock cords, that is exactly where we can help here at Ibex Marina Ropes. We have unrivalled experience with shock cords, and serve a wide range of sectors across the UK and beyond, including aerospace, military and defence, subsea and offshore, and sport and leisure – just to name a few.