If you’ve been in the RC hobby for a while, you’ve probably seen it—wires on your ESC or motor that don’t look as shiny as they used to. Instead of bright copper, the strands might look dull, darkened, or even greenish. That’s oxidization, and while it might seem minor, it can actually cause performance issues over time.
What Is Wire Oxidization?
Most ESC wires are made of copper, which is a great conductor of electricity. But copper doesn’t stay pristine forever—exposure to oxygen, humidity, and heat causes it to form a thin layer of copper oxide. This layer doesn’t conduct electricity nearly as well as clean copper, which means more resistance in the wire.
Sometimes, you’ll also see green corrosion (copper carbonate or copper chloride), especially if your RC car, boat, or drone has been exposed to moisture. That’s a sign the oxidation has gone a step further and is actively eating away at the wire.
Why It’s a Problem
At first, oxidation may just look ugly, but over time it can:
-
Increase resistance, meaning your ESC and motor don’t get clean power. This can cause sluggish performance or heat buildup.
-
Weaken solder joints, since oxidized copper doesn’t bond well with solder. This can lead to loose connections or intermittent power loss.
-
Accelerate wear if combined with high current draw, because the resistance turns into heat.
On high-performance setups where every bit of efficiency matters, oxidized wires can rob you of both speed and runtime.
How to Prevent It
The good news is, oxidization is manageable with some care:
-
Keep electronics dry – Moisture speeds up oxidation, so avoid wet runs unless your electronics are waterproofed.
-
Use protective coatings – Products like liquid electrical tape or heat shrink can seal solder joints and exposed wire.
-
Tin your wire ends – A fresh layer of solder on exposed copper keeps air and moisture away.
-
Check regularly – If you see blackened or green strands near the connector, trim back the wire and re-solder.
Fixing Oxidized Wires
If the oxidation is only on the surface, you can often scrape or sand the copper strands lightly before re-tinning. But if the corrosion has spread deep into the wire, the best option is to cut back to clean copper and re-solder the connection. In worst cases, replacing the wire entirely is the safest bet.
Tamiya ESC wires, for some strange reason, are very easy to become oxidized. If for whatever reason the wire(s) turns blue, it will fail to transmit signal and current. You will then need to replace it. Soldering can be done from the bottom of the PCB, which will be much easier. After rewiring, apply hot glue to prevent short circuiting.
A problem with this approach is that the original casing will have to be modified so give room to all these…
