'How To' Motorcycle Guides

The ‘How To’ Motorcycle Guides: 3 Easy Ways to Remove Rust from Your Motorcycle Tank at Home

Whether restoring a classic motorcycle or giving your daily rider a bit of TLC, dealing with a rusty fuel tank can be frustrating. Rust buildup can lead to performance issues, clogged fuel lines, and engine problems. Luckily, with the right tools and techniques, you can remove rust from your motorcycle tank at home and restore it to its former glory. This short guide will walk you through three rust-removal methods, offering practical solutions for every level of DIYer.

Why Does Rust Form in a Motorcycle Tank?

Rust results from metal coming into contact with oxygen and moisture over time. Motorcycle gas tanks are particularly vulnerable to rusting because they store fuel, which contains ethanol. Ethanol absorbs water, which can accumulate in the tank over time, leading to rust formation.

Some of the most common causes of rust in a motorcycle tank include:

  • Condensation: Humidity in the air can lead to water droplets forming inside the tank, especially if it isn’t stored in a dry area.
  • Old fuel: When left sitting for a long time, it can degrade, allowing moisture to separate and rust to develop.
  • Improper storage: Leaving a bike sitting for long periods, particularly with a partially filled tank, can allow oxygen to react with the tank walls, leading to rust.

Now that we understand why rust occurs, let’s examine the different removal methods.

Tools and Materials You’ll Need

Before you start the rust-removal process, gather these essential tools and materials:

  • Rubber gloves
  • Eye protection
  • Vinegar or hydrochloric Acid
  • Baking soda
  • Nuts, bolts, or small chains
  • A funnel
  • A fuel-safe sealant (optional)
  • A pressure washer or hose
  • WD-40 or another water-displacing spray
  • Cloths or rags
  • A container to catch old fuel and rust particles

Method 1: Vinegar and Baking Soda

If you prefer using household items, this method is one of the most popular and effective ways to remove rust without introducing harsh chemicals. The Acid in vinegar breaks down the rust, and the baking soda neutralises the Acid afterwards.

Step-by-Step Instructions:

  1. Drain the Fuel: Before starting, make sure your tank is empty of gasoline. Then, drain the old fuel into a safe container.
  2. Add the Vinegar: Pour white vinegar into your gas tank, filling it halfway. For more aggressive rust, you can fill the tank.
  3. Agitate the Tank: Once the vinegar is inside, add a handful of small nuts, bolts, or a short chain length. These will act as an abrasive to help break up rust as you shake the tank. Close the fuel cap tightly and shake the tank vigorously for a few minutes. Let the tank sit for 24 to 48 hours, occasionally shaking it to ensure the vinegar reaches all areas.
  4. Drain and Rinse: After the vinegar has done its job, drain the tank into a container and inspect the inside. If the rust is gone, rinse the tank thoroughly with water. For stubborn rust, repeat the process until the rust is fully dissolved.
  5. Neutralise with Baking Soda: Once you’re satisfied with the rust removal, mix a water solution and baking soda (about two tablespoons per gallon). Pour this into the tank to neutralise the vinegar and prevent further corrosion.
  6. Dry the Tank: Drain the tank, rinse it again with clean water, and dry it thoroughly. You can use a hairdryer or compressed air to ensure there’s no moisture left inside.
  7. Protect the Tank: To prevent future rust formation, apply a fuel-safe tank sealer or fill the tank with fresh gasoline to minimise air exposure.

Method 2: Electrolysis

Electrolysis is a highly effective and low-cost method for removing rust inside a motorcycle gas tank. It works by using an electrical current to break down rust. This method is more advanced but doesn’t require much special equipment.

Step-by-Step Instructions:

  1. Set Up the Tank: Drain your gas tank and remove any remaining fuel. You’ll need a power supply, such as a 12-volt battery charger, for this method.
  2. Prepare the Electrolyte Solution: Mix water and washing soda (sodium carbonate) in a 1:10 ratio and pour it into the tank until it’s complete.
  3. Insert a Sacrificial Anode: You’ll need a piece of steel or iron (the anode) to attract the rust. Place the anode inside the tank, but ensure it doesn’t touch the sides to avoid short-circuiting.
  4. Connect the Battery: Attach the positive lead from the battery charger to the anode and the negative lead to the outside of the tank. Turn on the charger, and bubbles form as the rust breaks down. Let this process run for several hours or overnight.
  5. Inspect and Rinse: After the electrolysis is complete, remove the anode and check the inside of the tank. The rust should have been converted into a soft, black material that you can easily wash out with water.
  6. Dry and Protect: As always, thoroughly dry the tank before use and protect it with a fuel-safe sealer or fresh fuel.

Method 3: Hydrochloric Acid

If you’re dealing with heavy rust, you may need something more substantial, like hydrochloric Acid. This powerful cleaning agent can dissolve rust quickly. However, it should be used cautiously, as it can damage the metal if left inside the tank too long.

Step-by-Step Instructions:

  1. Dilute the Acid: Hydrochloric Acid should always be diluted before use. Mix 1 part acid to 4 parts water. Always add Acid to water, not the other way around, to avoid a dangerous chemical reaction.
  2. Pour the Acid into the Tank: Carefully pour the diluted Acid into the empty gas tank. Wear gloves and eye protection, as hydrochloric Acid is highly corrosive.
  3. Let the Acid Work: Let the Acid sit in the tank for 10 to 15 minutes. If the rustre, you can let it sit for up to an hour, but monitor it closely to avoid damaging the metal.
  4. Drain and Neutralise: Once the rust is dissolved, drain the Acid and neutralise the tank by rinsing it with water and baking soda. This will stop the Acid from continuing to eat away at the metal.
  5. Rinse and Dry: Rinse the tank thoroughly with clean water and dry it completely before use.
  6. Apply Protection: Since hydrochloric Acid is so strong, it is recommended that a fuel-safe sealant be applied to prevent new rust from forming.

Preventing Rust in the Future

Once you’ve successfully removed rust from your motorcycle tank, it’s essential to prevent it from returning. Here are some tips for rust prevention:

  • Store Your Bike Properly: Always store your motorcycle in a dry place, especially during the off-season. Cover the bike with a breathable cover to prevent moisture buildup.
  • Keep the Tank Full: A full fuel tank minimises the air in the tank, reducing the chance of condensation forming.
  • Use a Fuel Stabilizer: If your motorcycle will be sitting for an extended period, adding a fuel stabiliser can prevent the fuel from breaking down and rusting the tank.
  • Regular Inspections: Periodically check your gas tank for signs of rust, especially after long storage periods.

Conclusion

Removing rust from your motorcycle tank might seem daunting, but with the right tools and techniques, it’s a manageable DIY project. Whether you opt for household solutions like vinegar and baking soda, try electrolysis, or use a powerful acid like hydrochloric Acid, there’s a method to suit every situation.

By restoring and protecting, you’ll not only keep your bike running smoothly but also extend its lifespan. Remember, rust prevention is key, so follow the recommended storage and maintenance practices to keep your tank rust-free for years to come.