Avoiding "Burning" in High-Current Electroplating
Too much current is just as bad as too little. Learn how to prevent burnt, powdery deposits on the sharp edges of your parts.
In electroplating, current is your friend—but too much of it will “burn” your parts. A “burnt” deposit is thick, dark, rough, and powdery. It has zero adhesion and will rub off with your thumb.
1. The High Current Density (HCD) Area
Electricity is lazy; it always takes the shortest path. On a metal part, this means the current concentrates heavily on the sharp outside edges, corners, and points. These areas receive far more current than the flat surfaces in the middle.
2. Why “Burning” Happens
When the current density exceeds the “Limiting Current” of the bath, the metal ions in the liquid cannot reach the part fast enough to keep up with the electrical demand. The bath begins to break down, creating a rough, non-crystalline metallic sludge instead of a solid plate.
3. How to Prevent Burning
- Current Thieves: Platers can place “sacrificial” pieces of wire or steel scrap near the sharp corners of your part to “steal” the excess current and protect the part from burning.
- Shielding: Placing non-conductive plastic shields between the part and the anode to block the direct flow of current to sharp edges.
- Bath Additives: High-quality brightening agents increase the “workable range” of the bath, allowing for higher currents without burning.
Precision plating is about controlling the flow of electricity. Platinex Industries utilizes advanced racking and current-shielding techniques to deliver uniform, burn-free finishes on even the sharpest geometries. Contact us for your precision hardware needs.