How to Clean Cast Iron
Cast iron is a common metal that has been used for thousands of years across various applications, including in the construction of bridges and in cookware. Whilst it’s commonly used for industrial applications and within the machinery sector, it is also fast becoming a common household material, be it on gates and fences or skillets and pans.
Unlike other prevalent metals like stainless steel, cast iron can’t be wiped down with harsh cleaning chemicals and rough, abrasive materials due to its unique properties – specifically with reference to cookware. We’ve put together this handy guide on how to clean cast iron so that you may clean your material without risking damage.
What is Cast Iron?
Before we get into how to clean cast iron, it’s important to first understand what cast iron is. Put simply, cast iron is the result of melting pig iron (iron ore) in a blast furnace. Other materials such as carbon and steel can be added depending on the intended use of the metal. As long the carbon content exceeds 2%, the metal is cast iron. A concentration of around 4% in relation to weight is standard, though it can vary.
Types of Cast Iron
There are several types of cast iron, with the most common being:
- White cast iron
- Grey cast iron
- Malleable cast iron
- Ductile cast iron
White Cast Iron
White cast iron is highly resistant to abrasion which makes it ideal for use in things like cement mixers and slurry pumps.
Grey Cast Iron
Grey cast iron is the most widely used type of cast iron and is characterised by its thermal conductivity and stiffness. It is used to make cast iron cookware, as well as flywheels and manifolds.
Malleable Cast Iron
Malleable cast iron is, as the name suggests, malleable. It also has excellent ductility, so it is commonly used to create things like tools, electrical equipment, and other machinery parts.
Ductile Cast Iron
Ductile cast iron is sometimes referred to as nodular or spheroidal graphite cast iron. Like malleable cast iron, the name of ductile cast iron is a testament to its main property: its ductility. For this reason, it is widely used for vehicle suspension parts and waterwork infrastructure.
Properties of Cast Iron
Whilst every type of cast iron has its own unique properties that lend themselves to various uses, cast iron as a general metal has a number of characteristics that separate it from the likes of steel and iron.
Cast iron is well known for its relatively low melting point which lends itself to easy malleability and increased versatility.
Cast iron is easy to cast into complicated shapes, making it ideal for creating all manner of parts and pieces of equipment.
When looked after properly (specifically in relation to cookware), cast iron is highly resistant to wearing.
Cleaning Cast Iron
Now you know what cast iron is, how it’s made, what its properties are, and the types of cast iron, we can look at how to clean it. If you’re wondering how to clean cast iron, there’s a good chance you’re using grey cast iron in the form of a skillet, pan, or other cookware piece.
The first step is to make sure you’re cleaning the cast iron as soon as it gets dirty. In the case of cookware, this means even doing it if it’s still hot. You may need to wear gloves to protect your hands from the heat in this case.
The next step is to remove any debris that may be stuck onto the cast iron. In the case of skillets and other bare cast iron cookware, you need to take care to avoid using soap or things like steel wool as this can damage the seasoning and mean you need to re-season more frequently. If your pan is older and has been well seasoned through persistent use, a mild soap can be used. Otherwise, use a sponge and some rock salt.
If you find debris is still stuck on, try using boiling water to loosen it. After this, rinse the pan well and use a towel to dry the cast iron. For bare cast iron, you will need to oil (season) it before putting it away. This means buffing vegetable oil into the surface of the pan using a paper towel.
All types of cast iron are prone to rusting, but steel wool is typically enough to remove it.
Buy Cast Iron
Rapid Metals is a leading supplier of cast iron in the UK. Our rounds and squares are made to measure and can be used across any application, be it industrial or hobbyist. To purchase cast iron, order securely on our website. Alternatively, for more information about cast iron, its properties, and how to properly clean and look after it, please contact us. We are experts in metal and our team will be more than happy to help.