I believe the material is oxidized copper, and I'm curious about its impact on internet performance.
I believe the material is oxidized copper, and I'm curious about its impact on internet performance.
Hello, I've been handling Ethernet cables and relocated the router. The phone cable, which serves as the VDSL infrastructure for internet access, appears blackened—like oxidized copper. Could this impact your internet performance? Please share the photos you took.
This is the cable inside the walls - I removed the rj11 jack for the upgrades, this is part of the single pair cable that's inside the wall and this is part of one of the wires.
The document shows a thick, solid core likely designed for AC power. It seems oversized—possibly around ten times thicker than necessary—but that’s fine. It appears to be a wiring hack from an earlier owner. There’s no sleeve present, suggesting it might be old knob-and-tube wiring. Back then, insulation wasn’t made with good materials, so air was used instead. The entire wall cavity was just the insulation jacket. Houses with this setup can’t be properly insulated unless the wiring is replaced. It could still function for low-voltage use. However, oxidation might become an issue over time; the outer wire may corrode while the inside stays intact, possibly affecting it in a few centuries but not now.
Thanks! I'm feeling secure until then. Just a note about the image—it's not overly detailed, it's just a close-up. Think of it as thin compared to something like an Ethernet cable. It looks more like a telephone wire than a power line, especially in this old house where every room has a phone socket.
Ah. I assumed it was 12 or 14 gauge solid wire. I’ve even used that type for strands in thick wires. That thin wire usually comes with a sheath on it. I’ve seen solid core Ethernet cables of that size, but they always had a protective layer. A bare wire without insulation is typically reserved for grounding and is much thicker than that. It might be old phone wire for RJ11, but still insulated. All these are still too thick for oxidation to impact their conductivity. The black oxide on the copper isn’t safe. It’s probably best to wash your hands just in case. Copper tends to oxidize, though not as aggressively as iron does. There are three different oxides depending on heat and oxygen exposure—red, black, and green. The black one is relatively hard and, to some extent, resists further oxidation, unlike iron oxide which readily degrades.
Thanks! The insulation is there, I took off the covering to reveal the interior. Once I’m back home I’ll capture a photo of the whole cable. I’m curious if somewhere deeper where it’s less exposed it hasn’t rusted, though I live in a humid coastal area and this cable has been inside walls for at least three decades.
I could possibly identify what the materials are. Unless it's a gas-tight cable sheathing, gas might seep in gradually. There were many phone cables that weren't waterproof or fire-resistant. It's likely they aren't rated for plenum use either, so burning it could release harmful fumes.
It could be possible. I’m not familiar with it, but it’s not out of the question. Regardless, the situation seems likely to remain stable in the near term. Regarding oxidation color, it depends on the amount of oxygen present—like the inside of copper pipes often appears black because tap water usually contains some air.