While it may be possible to buy a vintage adze with an uncoated head, you’ll find that most adze heads have a protective coating that has been designed to prevent them from rusting.
Rusty tools are very likely to be blunt, ineffective and potentially dangerous.
Using paint or a black oxide finish will help to protect your tool and prolong its life.
Painting an adze head provides it with a physical barrier against corrosion. Paint keeps air and moisture away from the surface of the tool to stop it from rusting.
The paint usually has to chip or wear away before the tool can go rusty.
Unfortunately, although this is a cheap way of protecting your tool, it isn’t foolproof. While it will slow down the rate at which your tool rusts, it is possible for metal to rust under paint.
Quick and easy to apply.
Finish can be in any colour.
Rust protection is only low level.
Can change the dimensions of the tool – the layer of paint could prevent it from fitting snugly onto the handle.
Black oxide is a durable coating that protects the tool from rust.
Steel can be coated with black oxide by being dipped into, or rubbed with, a special acidic cocktail. This causes a specific type of iron oxide, known as magnetite to form on the tool’s surface.
Magnetite (chemical formula Fe3O4) is best known for its use in cassette tapes.
Rust (chemical formula Fe2O3) is also a type of iron oxide.
Iron can only oxidise (rust) once. This means that once the tool has been covered in a layer of black oxide, it is chemically prevented from rusting again.
The process of coating steel with magnetite is known as ‘bluing’ due to the blue-black colour of the steel once the process is complete.
To fully protect the steel from rust, a water-displacing oil is applied to its surface. This draws out any water that has found its way into scratches or imperfections in the steel. It also makes the finish of the tool look more strongly black.
Oil can be reapplied to the surface of the steel at a later date to refresh the coating and keep it from rusting.
Black oxide tends to be used on hand-forged tools because it is cheaper to apply than industrial-standard coatings, such as zinc plating.
All black finish looks neat and tidy.
Provides a reliable anti-rust coating.
The coating itself is durable and is not easy to wear away.
Coating is very thin, but strong. Will not cause issues with fitting onto the handle.