Painting Prep For Rusty Surfaces


Surface preparation is the key to success with any painting project, and rusty surfaces are no exception!

In fact, if you skip the prep work on rusty surfaces, you are likely to find yourself painting the object all over again in the future. Rust will chip and flake over time, taking your nice new coat of paint with it. To avoid future frustration follow these steps!

Step 1: Prepare your work space

You will want to create a dry, well ventilated working environment. This can be especially difficult for large objects like grillsĀ  or mowers, so you may need to move outdoors to work. Wherever you decide to work, consider safety equipment like goggles, gloves, and a respirator to protect from paint fumes and rust particles. Cover any ground, nearby items, or close walls with drop cloths to prevent paint from getting out of control.

Step 2: Remove the rust

There are several ways you can remove the rust from your surface. Pay close attention to the extent of the rust, and the metal makeup of the object to determine which method is best for your project. Cast iron, steel, and galvanized steel have their own unique qualities and may require the use of slightly different products.

  • Start by scraping off all of the flaking rust with a wire brush, or a drill or Dremel bit made for metal sanding if space allows. This process should be relatively easy and only require a few passes. If that doesn't seem to be enough, your surface may be rusted to the point of structural damage.
  • After the roughest rust is gone, you may want to sand your surface for a smooth finish. Start with a coarse grain and finish with a smooth grain.
  • There are also chemical options for rust removal, but be sure to read the label carefully before selecting your product. Many of these chemicals are made for specific metals, and must be used with extreme care.

Step 3: Prime your surface

  • Be sure to clean any remaining grease, grime, dust, dirt, or other surface debris BEFORE priming and painting! Seriously. You'll thank us later. To remove stubborn layers of old paint, use paint stripper to eliminate what the scraper missed. Greasy messes can be cleaned up with mineral spirits or other de-greasing agent. A soft brush is helpful for dust.
  • Metal primer is available in both spray and brush-on formulas. Be sure to select the type that is best for your specific project.
  • Apply the primer in smooth, even coats. Be sure to cover every last bit of the metal being painted, or else moisture will inevitably get back in and force you to start all over one day! Use a small brush or a bit of cloth to prime in hard-to-reach spots.

Step 4: Paint!

When selecting a paint for your project, be sure to consider where the item will 'live' when you're finished. If it's already rusty, we're guessing it 'lives' outdoors, or near a water source. In that case, it is very important that you choose an anti-rust paint suitable for outdoor conditions - not just indoor!

  • Once the primer is completely dry, apply several thin coats of the desired paint color. Again, be sure the coats are thin, even, and cover every little bit of metal!
  • Make sure to allow each layer to dry thoroughly and completely before applying another. Applying additional coats of paint before the first one dries can result in issues like bubbling, cracking, and wrinkling of the paint finish. Again, you don't want to start this whole project over again down the road as the result of rushing a step.
  • Read the paint label for specific applications, but as a general rule, give your finished piece 48 hours to cure before exposing it to moisture.

Still have questions?

Visit your local Valu Home Center and speak to our knowledgeable associates for help choosing prep products, safety gear, paint, or primer. Stop in for project ideas, inspiration, and general know-how!