Lifting equipment storage practices leave the equipment reserved for the next use. And, as the saying goes, ‘out of sight, out of mind.’ It is the nature of bad lifting equipment storage. The damage caused by such practices is often not obvious and does not get noticed until equipment is needed for use.
Webbing is probably the first piece of lifting equipment to end up being stored wrongly. Either they are slung over a hook by a window or left in a bag after completing a job in the rain. Polyester and Nylon slings gradually lose their strength due to exposure to ultraviolet (UV) light. Indirect sunlight has the same effect and can deteriorate slings over a period of time, even if they are not exposed to direct sunlight. The deterioration caused is not evident on the surface. The fibers actually get weaker underneath the surface, and the sling can look the same after being stored by the window for a year as one that was stored in a dark cupboard.
Lifting slings are not the only equipment that is deteriorated by exposure to moisture. The effect can be even more severe on nylon. The fibers actually get weakened by moisture, and nylon is broken down completely in a process called hydrolysis. A wet sling that has been folded up for storage can look fine the next time it is used, but it actually has been deteriorated. Chain and shackles also get pitted from exposure moisture and corrode. It can look undamaged from the outside, but it can actually be able to withstand less than the load that it was designed safe for.
Chemical exposure is a damage mechanism that most people tend to overlook. Acids target nylon webbing swiftly at a low concentration, whereas alkalis target polyester. Neither type of chemical causes instant, noticeable damage. Rather, their damage mechanism is cumulative and occurs only under a load. Fumes are enough. Storing a sling next to battery charging equipment, rust preventive, or acid-based cleaning products exposes the sling to these chemicals, even if the sling never comes in direct contact with the chemical. This mechanism surprises people because the sling is not actually next to the chemical. Rather, the sling is next to where the chemical is used, and that is close enough.
Heat, while less important than the others, is still a factor. High temperatures over time cause hardening and a loss of strength in synthetic fibers. A workshop that gets hot over the summer means that the webbing left in the workshop has that hardening and loss of strength done to it.
It is not difficult to do correctly. Webbing slings should be hung on a rack or bar, not on top of one another, and in a dry, dark place away from all chemicals. It is also important to clean your chains before you store them, and do not store your chains on the floor. Shackle pins should not be fully closed while in storage. A seized pin on a job is a delay no one wants. Any piece of equipment that was wet when it came back from a job should be fully dried before it is stored instead of being placed in a sealed bag.
Many website users do not know that the checks sites do to determine if a lift is safe to use will not reveal a lot of the damage we have talked about. As an example, a visibly un-damaged sling that has been stored near a window for two years, will not fail the safety check, and should. Inspection dates on tags do not capture storage conditions. We do not allow equipment from going into a worse condition, than what it appears to be, due to correct storage practices.