How do you free rusted bolts?

How do you free rusted bolts? - Fix It Cape Town


Dealing with rusted bolts and nuts can be a frustrating and time-consuming task. Whether you’re a DIY enthusiast or a professional mechanic, encountering stuck or rusted fasteners is inevitable. Fortunately, there are several effective techniques available to help you release rusted bolts and nuts. In this article, we will explore some of these techniques, including the use of penetrating oils and impact wrenches, to make your tasks easier and more efficient.

Penetrating Oils: A Game-Changer

The Basics of Penetrating Oils

Penetrating oils are specially formulated lubricants designed to loosen rust and corrosion on metal surfaces. These oils have low viscosity, allowing them to flow into tight spaces and penetrate the rust layers that bind fasteners. When applied correctly, penetrating oils can weaken the rusted bond, making it easier to remove the bolts and nuts.

How to Use Penetrating Oils

  1. Start by applying a generous amount of penetrating oil to the rusted fastener, ensuring it reaches the source of rust.
  2. Allow the penetrating oil to soak into the rusted area for the recommended duration mentioned on the product label. This typically ranges from a few minutes to several hours.
  3. After sufficient soaking time, try loosening the fastener using a suitable wrench or socket. Apply gentle and steady force, and avoid using excessive pressure that may damage the fastener or surrounding components.
  4. If the fastener doesn’t budge, reapply more penetrating oil and repeat the process. Multiple applications may be necessary for stubborn rusted bolts and nuts.

Popular Penetrating Oils on the Market

There are various brands of penetrating oils available in the market. Some popular options include:

  • WD-40 Specialist Rust Release Penetrant
  • Liquid Wrench Penetrating Oil
  • PB Blaster
  • Kroil Penetrating Oil

These oils have different formulations and come with their own unique features and benefits. Consider trying different brands to find the one that works best for your specific needs.

Heat: A Powerful Assistant

The Science Behind Heat

Heat is a time-tested technique that can help break the bond between rust and metal. When heat is applied to a rusted bolt or nut, it causes the metal to expand while loosening rust’s grip, making it easier to turn the fastener.

How to Apply Heat Safely

  1. Make sure the area around the rusted fastener is clean and free from any flammable materials.
  2. Use a propane torch, heat gun, or another safe heat source to apply heat directly to the rusted fastener. Avoid using an open flame or excessively high temperatures.
  3. Heat the fastener for a few minutes, focusing on the base of the bolt or nut where it connects to the metal. Apply heat evenly to avoid damaging the surrounding components.
  4. Once the fastener is sufficiently heated, attempt to loosen it using a wrench or socket. The combination of heat and penetrating oil can significantly improve your chances of success.

Safety Precautions

When using heat to release rusted bolts and nuts, it’s crucial to prioritize safety:

  • Wear heat-resistant gloves to protect your hands from burns.
  • Make sure the heat source is stable and placed on a non-flammable surface.
  • Keep a fire extinguisher or a bucket of water nearby, just in case.
  • Avoid excessive heating as it may damage the fastener or surrounding components.

Impact Wrenches: The Power of Air or Electricity

Introducing Impact Wrenches

Impact wrenches, available in pneumatic and electric versions, are powerful tools commonly used in the automotive and construction industries. These tools utilize high torque and repetitive hammering action to loosen fasteners, including rusted bolts and nuts.

How to Use an Impact Wrench

  1. Select an appropriate socket size matching the fastener you need to loosen.
  2. Attach the socket to the impact wrench securely.
  3. Position the socket onto the rusted bolt or nut and ensure it is correctly seated.
  4. Depending on the type of impact wrench, connect the air compressor (for pneumatic) or ensure the electric impact wrench is properly connected to a power source.
  5. Set the direction switch on the impact wrench to “loosen.”
  6. While firmly holding the impact wrench, apply steady pressure on the trigger to activate the hammering action.
  7. The rapid bursts of torque delivered by the impact wrench will help break the rusted bond and facilitate fastener removal.

Impact Wrench Safety Measures

It’s essential to follow these safety measures when using an impact wrench:

  • Always wear appropriate safety equipment, including safety glasses and gloves.
  • Use impact wrenches with a torque control feature to prevent overtightening or damage to the fastener or surrounding components.
  • Be cautious of the torque generated by impact wrenches, as it can cause sudden movements or jarring. Maintain a firm grip and secure footing to avoid accidents.


Q: Are there any homemade rust loosening solutions?

Yes, there are a few homemade solutions that can be effective in loosening rusted bolts and nuts. Here are a couple of examples:

  1. Vinegar and Baking Soda Mixture: Create a paste of equal parts vinegar and baking soda. Apply the paste onto the rusted fastener and let it sit for several hours. The acid in vinegar and the abrasive properties of baking soda can gradually dissolve rust.

  2. Coca-Cola: Pour Coca-Cola onto the rusted bolt or nut, ensuring it is completely submerged. Let it sit overnight or for a few hours. The phosphoric acid in Coca-Cola can help break down the rust layers, making it easier to release fasteners.

Remember, homemade solutions might not be as potent as dedicated penetrating oils, but they can still provide some assistance in certain situations.

Q: Is it safe to use an impact wrench on fragile or delicate components?

Impact wrenches deliver immense power, making them unsuitable for fragile or delicate components. Using an impact wrench on such parts may cause damage or breakage. Exercise caution and assess the strength and sturdiness of the components before using an impact wrench. If in doubt, consider alternative methods or seek professional assistance.


When confronted with rusted bolts and nuts, it’s crucial to remain patient and employ the right techniques for successful removal. The combination of penetrating oils, heat application, and impact wrenches can significantly increase your chances of loosening stubborn rusted fasteners. Remember to prioritize safety, choose the appropriate tools and lubricants, and take your time to avoid unnecessary damage to the fasteners or surrounding components. With these effective techniques at your disposal, you can save time, effort, and frustration while successfully tackling rusted bolts and nuts.

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