Why zinc matters
One of the biggest problems for classic cars is corrosion: without a proper galvanising process on the body, the greatest threat is rust attacking the steel. Many owners don't pay much attention to small rust spots that appear over time on the bodywork — unaware that these spots can destroy a car that would otherwise be in sound mechanical condition.
What is rust?
Rust is the general term for iron oxides — the red-coloured oxides that form through the reaction between iron and oxygen in the presence of water and humidity. Over time, the combined action of oxygen and water transforms any iron object into rust and, eventually, causes its disintegration.
Unlike the patina that forms on copper and actually protects the metal, rust has no beneficial effect on iron or steel — quite the opposite. Rust is the corrosion process of iron and iron alloys such as steel.
What is zinc?
Zinc is a bluish-white metal that becomes malleable around 100–150 °C. It is produced from ores and compounds, and is used in alloys with other metals to protect them from oxidation. Protective coating against iron and steel corrosion is zinc's most important application.
- Thermal zinc plating
- Galvanising (electroplating)
- Spray (metalising)
Our process
We use a Flamespray MK61 flame-metalising unit. Before metalising, the surface must be stripped of every layer of paint and lacquer so only bare metal remains. Next comes straightening the sheet, filling any voids, and polishing to a smooth surface.
The zinc spray process feeds zinc wire into the centre of the gun, where an oxygen-based flame melts and pulverises it onto the substrate using combustion gases and compressed air to achieve the required velocity.
Although flame-sprayed zinc-plating is relatively fast — so we can move on to the next restoration stage quickly — it is one of the most important recondition steps, protecting the body for the long term. It must be done with care to get the best results.