Corrosion and Harness Check
Over the last year, I have been doing a fair number of inspections of PPE (Personal Protective Equipment) in the adventure industry in South Africa and abroad in the UK. These have consisted mostly of harnesses, slings, carabiners, zipline trolleys/pulleys, rescue equipment, and helmets for zipline sites and adventure parks.
Some of these sites were located on a beachfront or in a high humidity environment. One thing that I noticed was high amounts of corrosion in certain parts of the harness. Some harnesses had to be taken out of service due to the corrosion on critical components like the dorsal D ring where the safety line is attached. Surprisingly some of these harnesses were only in use for a year.
So here are some notes on corrosion on harnesses how to check the corrosion on your harness and how to prolong the life of the harness in these more extreme operating environments.
What is Corrosion and how does it form?
Rust forms when metals are exposed to oxygen and moisture. There is a chemical change in the metal that starts to take place. The metal looks solid to the eye but water molecules are able to penetrate tiny gapes in the metal causing corrosion. Exposure to salts such as seawater, sulfur dioxide, and carbon dioxide increases the speed at which corrosion occurs.
Why is corrosion bad?
Corrosion is bad because it weakens the structural integrity of the metal. To the naked eye, it looks brown and has bumps on it. See Figures 1.1 and 1.2 for reference. The metal continues to deteriorate internally effectively weakening its strength and therefore safety is compromised.
How do I check if the corrosion is too bad and needs to be quarantined?
If you did regular PPE inspections you should be able to spot rust forming early on. When rust just starts to form you should see brown speckles on the metal (refer to figure 2.1). This is known as surface rust, the best way to treat this is with a wire brush. Clean the rust away and then wipe with a damp cloth.
Upon re-inspection, you should be able to see if pitting has occurred or not. Pitting is when you see holes or dents in the metal where the rust has formed. If this has happened the structural integrity of the harness has been compromised and needs to be removed from service. If flaking has occurred the harness also needs to be removed from service.
How do I prevent corrosion on my harness?
- If you are using the harness in a more extreme environment it is best to make sure it is stored in a well-ventilated room.
- If there is high humidity it may be prudent to install a dehumidifier in the storeroom as this ensures the harnesses do not stay damp.
- Do not store the harness wet, if possible allow it to air dry completely (out of direct sunlight) before storing the harness.
- If you use the harness in a harsh environment regularly wash the harness with clean water.
- Do not hang the harness by the metal D-ring as this causes weighted contact between moist webbing and metal. Consider storing by hanging on a wooden peg.
- If using soap to clean the harness ensure it will not damage the harness by looking at what products the manufacturer recommends. Nikwax is a great product that is approved by most manufacturers. A link to the product can be found here
- When rubbing rust off the metal parts make sure the particulates do not get into the webbing as this may cause the webbing to erode.
- When rubbing the metal parts with a wire brush wear protective eyewear as this will prevent metal flakes from getting into your eye.
- If in doubt quarantine the harness and ask for the manufacturer’s recommendation.
Always follow the manufacturer’s recommendations on how to clean, store and care for a harness. And don’t forget to check your harness for corrosion damage.
Written by: Darren Erasmus