How to Clean Rust Out of an Air Compressor Tank

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Rust is one thing you don’t want in your air compressor. If you haven’t used your air compressor for a long time, it is already rusted. This is probably why you are here to know how to clean rust out of an air compressor tank.

How to Clean Rust Out of an Air Compressor Tank

If your compressor tank has rusted, you are better off replacing it than spending on repairs and fixes. Removing rust from a compressor tank compromises its quality and will more likely do more harm than good.

If you try to remove rust, especially from the inside of your compressor tank, it will weaken the structural quality, which could result in taking in less than the recommended pressure.

Some rust-removing products like phosphoric acid and other chemicals can also damage the seals and O-rings of the compressor. Hence, the reason why it’s better is just to get a new one.

Ways You Can Clean Rust Out of an Air Compressor Tank

These are the various ways you can clean out rust from your tank:

  • Use a rust converter that contains chemicals that may stick to the inside of your tank when not drained fully. You may also need a wire brush to scrape hard to remove rust.
  • Disassemble the tank and scrape away the rust. This will require some power tools and better working with professionals, resulting in high expenses. That’s why it’s just better to get a new one.
  • Some gas tank repair kits may also have a solution for rust and instructions on how to use it.
  • Get a bag of pea gravel and put them inside the tank. Roll your tank for 10 to 30 minutes. Pea gravels have sharp and rough edges that will scrape out rust from inside your tank.
  • Although rare and expensive, you can also remove rust from your tank via electrolysis. It uses electric current to decompose the rust to be drained quickly.

These are just some methods you can use to clean rust off of your tanks. Some cost a lot, and it’s also evident that most methods can do damage to the interior of your tank.

What to Use for Cleaning

Here are some things you can use to clean your rusty tank:

  • Rust converter
  • Phosphoric acid
  • Ball bearings
  • Drywall screws
  • Pea gravel
  • Coca Cola

Anything that has rough or sharp edges that can help scrape the rust off. Also, liquids can dissolve rust. You just put them inside the tank and roll or shake or spin the tank so the objects can cover the whole area inside.

Cleaning Your Tank to Prevent Rust

You should consider cleaning your tank regularly to prevent rust. This way, you won’t have to worry about replacing your compressor or opening it up to scrape off the rust. Here are the steps for cleaning your tank to prevent rust:

  1. Make sure your air compressor’s switch is off, and it is unplugged. The tank should also be drained of air.
  2. Open the drain valve of the tank.
  3. Drain the water tank and other particles like rust, oil, and sludge.
  4. Let the tank dry out by placing it in a dry environment and leaving the valve open.
  5. Once you make sure, it’s dry, close the drain valve tightly so no moisture gets in.

Why Rust Forms in Your Air Compressor Tank

Rust forms inside your air compressor tank because of water carried into the tank by moisture. The water makes a chemical reaction with iron and oxygen, which results in rust.

Air compressor sucks air and anything that comes with it that including water vapor. It condenses inside the tank and becomes liquid water which is the primary cause of rust formation.

Hence, if you notice any water forming inside your tank, you should drain it immediately. If it has formed excessively for too long, chances are your tank may already have formed rust, and it’s better to just replace it.

Tips for Preventing the Formation of Rust

Since removing rust is problematic and often not recommended, it’s better to just keep your tank from rusting. You won’t have to consider damaging the integrity of your tank just to remove rust.

Here are some things you can do to prevent rust from forming in your tank.

Drain Regularly

Draining your tank every one to three uses should eliminate any water from forming inside your tank. It’s also great for maintaining the accuracy of your compressor’s gauge in measuring total tank capacity.

Leave the Drain Open Between Uses

Leaving the drain open between uses also allows water to dry so there won’t be water buildup when it is not in use. Leaving the drain open after usage is a good habit for keeping it dry and preventing rust.

However, don’t leave it out for too long or in a humid environment, as it could also be a source of moisture buildup. Hence, you should leave your tank to drain in a dry room.

Make Use of Aftercoolers or Automatic Tank Drain

Automatic tank drains, as the name implies, will automatically drain your tank, so you won’t have to do it yourself manually. It’s a convenient way to keep the draining schedule consistent and on time.

Installing an aftercooler in your tank prevents any water vapor from forming inside your tank. The aftercooler is a filter that gathers warm air and cools it down. It redirects water vapor outside instead of it forming in the tank.

Use Filter Dryer or Water Traps

Water traps are simple devices you can use to prevent rusting. They work by filtering both moisture and debris from the air. The water trap will limit the water collected in your compressor tank.

The best filter dryer for air compressors combine both filtering and regulating. Much like water traps, they filter moisture and debris so your compressor tank won’t accumulate water and debris faster.

Use an Air Dryer

An air dryer reduces the amount of moisture in your compressor tank. It works much like a dehumidifier in keeping the environment dry. There are different types of air dryers, and they are:

  • Refrigerated dryers
  • Desiccant dryers
  • Chemical dryers
  • Membrane air dryers

Each one of them has its pros and cons. You may favor one over the other depending on what you are looking for and what your compressor needs.

Why You Shouldn’t Fix the Rust Yourself

As I mentioned before, cleaning rust out of a tank is risky, especially if you don’t know what you’re doing. Most of the time, what you do to fix the rust will do more harm than good.

Damage to the structure of your tank will likely cause a violent rupture if you fail to monitor the air pressure exceeding the recommended level.

If you have a durable tank, trying out the methods to remove rust may be okay. However, do make sure that you monitor your compressor so it doesn’t get put into situations where.

Is It Safe to Use a Rusty Air Compressor?

No, it’s not safe to use a compressor when it’s rusty. Rust may cause overheating or thinning of the tank, which is bad for your compressor. You may get into an accident if you’re not careful and when the machine goes over its limit.


Cleaning rust out of your air compressor tank isn’t recommended. You’re better off replacing it rather than doing unorthodox methods which could endanger its structural integrity and end up causing an accident.