How to Remove Yellow Rust Spots on Car Paint

If you see yellow/brown colored spots on your car's white or silver colored paint, do not be alarmed. It's rail dust and it's a common issue that is easily fixable.

yellow rust spots car paint

It's Rust

You may think there is a defect in your paint's finish but it's actually rust. The rust is due to very small pieces of metal shavings that have embedded themselves in your car's paint. These metal shavings are called rail head dust because they come from metal shavings that are a result of train car wheels running across railroad tracks. The metal shavings float in the air and then land on your car's paint finish. Eventually they rust and the result is the brown spots you see on your paint. These small metal particulates also come from the use of metallic brake pads and rotors.

Many cars have this issue but may not be visible unless it's a light colored car - especially white. The issue can easily be fixed and should be done as soon as possible.


What You'll Need:

Clay Bar (Fine grade)
nextzett Perfect Shine

    The issue can easily be fixed with a detailing clay bar. Detailing clay is a mixture of resin and polishing abrasives. It's not regular earth clay so don't think you can save money and head to your local arts and crafts store! Detailing clay can remove what paint polish can't  - such as rail head dust, paint overspray and dried sap.

    Step 1

    First, remove your clay bar from it's packaging and knead it with the palm of your hand to make it more malleable. Then form it so that you have a nice flat surface. Set aside for use in step 2. ALWAYS keep the clay on a clean surface when not handling. If you drop it on the ground, it is considered useless and you must throw it away. Do not use or you will scratch your car's paint finish.

    With your car in the shade so that the paint finish is cool to the touch, make sure the area you are treating is clean and dry. 

    Step 2

    Apply Perfect Shine on the surface to be treated - this makes the surface slick and allows the clay to glide effortlessly without scratching the paint finish. Take the clay bar and without any pressure, gently glide it along the surface of the paint finish. Apply Perfect Shine to the surface as needed so the surface maintains its slickness. If the clay sticks to the paint while you apply it across the surface, apply more Perfect Shine. Do not allow the clay to drag across the surface or it will cause scratches.  

    As the clay pulls up contaminants, be sure to re-knead to expose a fresh, clean side. Continue the process until you've finished the car.


    It's impossible to prevent rail head dust from contaminating your paint so you'll want to clay your car at least once a year. If you don't have a white car that makes seeing rail head dust easier, you can check your paint by using the bag test.  Place your hand in a regular plastic sandwich bag. You can also place a piece of cellophane between your hands and the paint. Whichever one you use, make sure it's clean. Now, on a washed and dried paint finish, run your hand across the surface. If it feels rough, the finish needs to be treated with clay. If not, you can hold off - the paint isn't contaminated. It's that simple. The plastic bag has a way of enhancing your sense of touch to reveal the true condition of the paint that bare hands can't determine.

    For best results, polish and wax your car after you have clayed it. This remove ALL paint contaminants for the smoothest and best finish possible. Apply a protective wax like No. 3 Polish & Wax to protect the paint finish or for longer lasting protection, apply SF3 Premium Protect.  

    If you have any questions, contact us!