Emergency repair of conductive fabrics
Antoine Gouin
In this article, we offer you tips to maximize the lifespan of your conductive fabrics and give them a second wind once they start to degrade. To learn more about the differences between the various conductive fabrics, see our article Metallic jackets: Which fabric to choose?.
What is a conductive fabric?
As its name suggests, the purpose of conductive fabrics is to conduct electricity. In foil, the conductive jacket and part of the mask bib are made of conductive fabric. In sabre, the same is true for the entire bib, the conductive jacket and the cuff of the glove. The FIE regulations stipulate that the electrical resistance from any point of a conductive fabric to another point must not exceed 5 Ohms (unit of measurement of electrical resistance). For Quebec tournaments, a resistance of up to 15 Ohms is tolerated. See our Rules for Equipment page to learn more about the requirements of the different tournaments.
Before we continue, it is necessary to delve a little further into what electrical resistance is. Electrical resistance is what impedes the passage of electricity; it is the opposite of conductivity. There are several phenomena that can increase the electrical resistance of a conductive fabric:
- Metallic threads that are bent too often will weaken and become thinner.
- Metallic threads that are too worn become thinner, either by receiving hits from the opponent's blade or simply by abrasion in the fencing bag.
- Metallic threads that are dirty or oxidized. This poorly conductive layer attaches to the outside of the threads and impairs electrical contact with the test probe and the opponent's blade. Dirt can be dried sweat, soap scum, etc.
- In the case of non-metallic conductive fabrics, dirt and the degradation of the chemical treatment both contribute to increase the electrical resistance.
Corrosion and oxidation
Corrosion is a natural phenomenon that mainly affects conductive fabrics made of silver-plated copper. It attacks the metal directly and deteriorates it. Corrosion changes the chemical composition of metals and changes its properties. Therefore, it can be slowed, but cannot be reversed.
Corrosion begins on the surface and progresses towards the interior of the metal. If it is not far advanced, it will appear black, which is the color of silver oxide. More advanced corrosion will be green, the color of copper oxide. This indicates that the silver plating of your fabric has been completely worn through or corroded in these places.
If your equipment starts to oxidize or corrode, but the electrical resistance still meets the conductivity standards, the only thing to do is make sure to dry it properly after each use, in order to limit its degradation. This discoloration is not aesthetically pleasing, but several fencers have the same issues and there is no need to worry about it.
If the electrical resistance of your equipment gets too high, there is a trick that occasionally works. To remove some of the corrosion and try to restore the conductivity of the fabric, rub the fabric gently on itself, metal on metal, on the affected areas. The goal is not to remove all of the oxidized color, but simply to make a few spots of the metal appear shiny.
However, this trick doesn't always work. If the metallic threads are too corroded, they become too thin and too weak. In this case, either they are too thin to conduct electricity properly, or they simply break.
Some fencers and websites recommend a trick that uses an ammonia solution to deal with corrosion problems. Imex Sport has no experience with this method and therefore cannot recommend it. If you want to try it, it's at your own risk.
My equipment is refused at a tournament, what do I do?
If your conductive equipment is refused because of its electrical resistance, ask the armorer in charge of weapon control what the problem is. If it's corrosion, a small hole or a "spot" where the metallic threads are too worn or even broken, there are possible solutions.
If the affected area is not too big (maximum approximately 5 cm by 10 cm), it is possible to sew a patch over it. This piece of metallic fabric is the same material as that of the jacket, bib or cuff and will restore its conductivity. If time is of the essence, for example during a tournament, it is also possible to make a temporary repair using a self-adhesive patch. After the tournament, however, it is better to sew a permanent patch to extend the life of your equipment.
If the affected area is too large, or if there are too many small areas everywhere, this equipment can no longer be used in tournaments. However, nothing prevents you from keeping it for training at the club and using your next, new equipment in tournaments only.
To purchase a self-adhesive patch or a sew-on patch kit, visit the Tools & Testers section of our site. Although it is essential that a patch be well sewn, it is not necessary to know how to sew. If you need help, ask the tournament armorer, or other fencing parents; you are sure to find someone who can sew. However, they will not be able to help you if you do not have the tools. See the article How to sew a patch onto a conductive jacket to learn how to apply a patch yourself, or to help someone help you.