How To Use An Angle Grinder To Remove Rust – A Step-By-Step Guide

Rust can be a real pain, especially when it comes to metal objects. It not only looks unsightly but can also weaken the structure of the metal.

Fortunately, there’s a solution – an angle grinder. This powerful tool can make quick work of even the rustiest of surfaces, leaving you with a clean and polished finish.

But with so many different types of abrasive discs available, it can be hard to know which one to choose. In this article, we’ll take a closer look at the best ways to remove rust with an angle grinder, including the pros and cons of each method.

So grab your safety goggles and let’s get started!

How To Use An Angle Grinder To Remove Rust

Before you begin, it’s important to take some safety precautions. Make sure you’re wearing protective gear, including safety goggles, gloves, and a dust mask. You should also secure the object you’re working on in a vice or clamp to prevent it from moving around.

Now, let’s take a look at the different types of abrasive discs you can use with your angle grinder.

Understanding Rust And Why It Needs To Be Removed

Rust is a common problem that affects metal objects, and it occurs when iron or steel is exposed to moisture and oxygen. When rust forms, it weakens the metal and can eventually cause it to corrode and break down completely. This is why it’s important to remove rust from metal objects as soon as possible.

There are different types of rust, including flash rust and surface rust, and they can be removed using an angle grinder with the right abrasive disc. Flash rust is a thin layer of rust that forms on metal surfaces after they have been cleaned or exposed to moisture. Surface rust is a more advanced form of rust that has penetrated deeper into the metal.

To remove rust using an angle grinder, you’ll need to choose the right type of abrasive disc. For mild rust, such as flash rust or surface rust, you can use a wire wheel or a resin sanding disc. A wire wheel is best for uneven surfaces and gives a nice finish when complete. A resin sanding disc is the fastest way to remove rust, but the lower the grit of the resin disc, the rougher the finish.

It’s important to note that removing layers of mud and grease before starting the process should reduce timescales and increase effectiveness. On some heavily rusted parts it may help to give the item a light wire brushing after some initial electro-cleaning as quite a bit of surface rust could have been loosened.

Safety Precautions When Using An Angle Grinder

Using an angle grinder can be dangerous if proper safety precautions are not taken. Here are some important safety tips to keep in mind when using an angle grinder:

1. Use both hands to operate the grinder: One hand should grip the handle and dead-man switch (if provided), while the other hand supports the weight of the tool.

2. Allow the grinder to ‘run up’ to operating speed before applying it to the job.

3. Hold the grinder against the work piece with minimum pressure, so the disc does not ‘grab’ and cause it to kickback.

4. Never bump the grinder onto the object, or let the disc hit any other object while grinding.

5. Keep the grinding disc at a 15 to 30-degree angle to the object. Ensure the work piece is held firmly, either as part of a larger item or in a bench vice.

6. Where possible, keep the work at waist height during grinding.

7. Adopt a comfortable stance with feet apart so you feel well-balanced, and ensure you have a clear view of the job never use a grinder between your legs while sitting on the floor.

8. Stop at regular intervals for a short break to rest your hands and arms.

9. Never put a grinder down until the disc stops rotating.

10. Remove the plug from the power point before changing discs.

11. Never use a cutting disc for grinding or a grinding disc for cutting.

12. When not in use, disconnect the power and place the grinder on a bench with the disc facing upwards.

Remember, wearing correct safety gear before using angle grinders is essential for your protection. A full-face mask, hand gloves, eye and hearing protection, suitable attire, natural fiber clothing, and apron, if needed, are all forms of protective gear. Avoid wearing loose clothing and tying long hair.

Additionally, don’t clamp portable grinders in a vise for grinding hand-held work, do not force wheels onto a grinder that is the wrong size or change mounting hole sizes, do not tighten the mounting nut excessively, do not put the grinder on the floor or working surface until the wheel has stopped turning, do not use a wheel with a maximum RPM that is lower than the RPM rating of the grinder, do not keep any materials close to the grinding wheel when it is not in use, do not wear loose clothing or dangling jewelry as they may get caught in the moving parts of the grinder. If you have long hair, keep it tied back.

By following these safety precautions when using an angle grinder, you can ensure that your work is completed safely and efficiently.

Choosing The Right Abrasive Disc For Rust Removal

When it comes to rust removal, choosing the right abrasive disc is crucial to achieving the desired results. The first step is to assess the size and severity of the rust you’re dealing with. For smaller areas of rust, a lower-grit flap disc can be used. However, for larger areas or tougher rust, a higher-grit flap disc is needed.

For a balance between aggressiveness and flexibility, wire wheels are recommended. They can effectively tackle surface issues as well as tight spots and pits that are common with severe oxidation.

If you’re working on aluminum, which has a lower melting temperature and can easily coat the flap disc during grinding, it’s best to use a T29 conical disc at a 15-degree angle for maximum surface contact during stock removal. For surface cleaning or achieving a smooth finish, a T27 flat disc parallel to your work area is recommended. It’s important to use light and even pressure to optimize the grinding process and reduce loading.

Flap discs designed for wood are similar in nature to those designed for metal, and aluminum oxide grits can be used for wood applications. To avoid deep scratches, start with a heavy grit and work your way up to lighter grits (100+) for a final finish. For wood sanding, work your way through 120, 150, 180, and 220-grit sizes to achieve a furniture-grade surface.

For paint or rust removal applications, non-woven flap discs or those with aluminum oxide are ideal tools. They can grind and finish in a single operation while offering a smooth and controlled grind.

When working on concrete surfaces, silicon carbide or diamond flap discs are needed for aggressive stock removal. These materials are among the hardest in the world and allow you to work on concrete surfaces without the need for high pressure. These flap discs have rigid backings and can also be used on other surfaces such as engineered stone, granite, marble, and ceramics.

Alternative Methods For Rust Removal

While the vinegar, baking soda, and salt method mentioned above is a great option for smaller items, there are other alternative methods for removing rust from larger metal objects. One such method is using wire wheels, which are our top recommendation for the best way to remove rust with an angle grinder. These twisted wire configurations are tough enough to grind through even the rustiest of areas while remaining flexible enough to reach the hard-to-reach spots.

Another option is strip discs, which performed well in our test. However, the only downside is the quicker degradation of the abrasion matrix. Since these tools use nylon as the webbing material, you’ll need to have a few of these on hand to make it through larger jobs. If you choose to go this route, consider stocking up on a variety of grits and discs to ensure your workflow is uninterrupted.

Flap discs are also an option for removing surface rust quickly. However, the rigid backing material prevents the abrasive elements from reaching the pits that are commonly seen in heavily-rusted metals. We’d recommend this for removing rust from surfaces that aren’t suffering from any severe corrosion like pitting.

It’s important to note that grinding will be the most aggressive abrasive that you can apply to metals, so use extreme caution when you apply an angle grinder on a rusted object, as it can damage the metal if it is still there underneath the rust. Use the grinder for the heaviest accumulation of rust to remove it quickly. It’s also good to note that grinding points and bits in your rotary tool accessory kit can be used for smaller more detailed areas in your object, as they tend to be very small and can get into many nooks and crannies so you can clean specific areas in your object with precision.

The mechanical method is another safe and easy way to remove rust from metal tools. This process requires the application of power tools like an angle grinder, sander, or a drill fitted with a surface finishing disc, cup brushes, or wire wheels. Grinding metal with an abrasive tool easily removes rust and other surface coatings.

Finally, if you’re looking for a quick and fuss-free method of removing rust from your metal items, consider using abrasive buff wheels attached to a rotary tool such as a Dremel. By gently moving the abrasive across the metal, within seconds the rust is gone. If you want to bring the metal back to its original shine, use different grades of abrasive buff wheels for pre-polishing and final polishing.

Tips For Maintaining A Rust-Free Surface

Maintaining a rust-free surface is important to ensure the longevity of your metal object. Here are some tips to keep in mind:

1. Keep the surface clean and dry: Moisture is one of the main culprits behind rust formation. Make sure to keep the surface clean and dry at all times. If you notice any water or moisture on the surface, wipe it off immediately.

2. Apply a rust inhibitor: Rust inhibitors can help prevent rust from forming on the surface of your metal object. You can find rust inhibitors in spray form or as a coating that you can apply with a brush.

3. Store your metal object properly: If you’re not using your metal object for an extended period of time, make sure to store it in a dry and well-ventilated area. Avoid storing it in damp or humid places.

4. Use a protective coating: Applying a protective coating, such as paint or varnish, can help prevent rust from forming on the surface of your metal object.

By following these tips, you can help ensure that your metal object remains rust-free and looks great for years to come.