How To Remove Rust from Metal
Learn three ways how to remove rust from metal and two ways to prevent rust from coming back
IntroductionPatio furniture, outdoor tools and lawn machines all eventually get rusty. Learn how to remove rust from metal and how to protect the metal so that it doesn't come back.
- Angle grinder
- Cordless drill
- Dust mask
- Hearing protection
- Orbital sander
- Paint scraper
- Paint tray
- Safety glasses
- Sanding block
- Wire brush
- Chemical rust removers
- Metal paint
- Metal primer
- Rust converter
You’re surrounded by tools, furniture and machines made out of steel. And when the coatings on those products crack, rust starts to bloom and the battle is on. You can attack rust early and nip it in the bud, or you can wait until you have a full-blown war on your hands. Either way, you’ll need a battle plan on how to remove rust from metal and a complete list of weapons at your disposal to start the process.
We’re going to show you the five ways how to remove rust from metal—three methods to remove it and two steps to prevent it from coming back, along with the best rust remover.
Project step-by-step (14)
Grind, Sand or Scour Off the Rust
If you don’t want to use chemicals and you also want to remove the paint along with the rust, use a power tool like a grinder, sander, oscillating tool or drill to remove rust from metal tools. Whichever tool you choose, always start with the coarsest abrasive to for how to remove rust from metal and pockmarks. Once the rust is gone, switch to a finer grit to smooth out the swirls and grooves caused by the coarse grit. For the smoothest paint job, finish sanding with 400-grit wet/dry paper.
Match the Abrasive to the Shape
- Use flap discs, fiber discs and sanders on large, flat areas.
- Switch to wire wheels for seams, corners and rounded rusted metal areas.
- Note: A wide range of stripping, grinding and sanding attachments are available for grinders.
- Use a detail sander for rusted metal corners, tight spots and small details.
- Drill-mounted wire wheels and stripping discs can be used as a rust remover instead of or in addition to grinders, though they don’t have as much power or cover as much surface area.
- Finishing and random-orbit sanders are also useful tools for rust removal on flatter surfaces.
The Chemical Removal Method
The old standby rust remover chemicals contain either phosphoric or hydrochloric acid to dissolve the rust. They’re harsh chemicals that give off some pretty intense fumes, so suit up with rubber gloves, goggles and a respirator. Find them in the paint department at any home center. You’ll also need an old paintbrush, a waste tub, a 3-inch putty knife and rags.
- Apply the chemicals with the paintbrush and wait the recommended time for the chemicals to work.
- Scrape off the liquefied rust.
- Note: You won’t get it all in a single step—count on multiple applications to completely remove heavy rust buildup. Consider a gel formula when removing rust on vertical surfaces. It’ll cling better and result in less runoff.
Or Try Safer and Gentler Chemicals
- Note: Try one of the newer non-toxic and acid-free soaking solutions. These chemicals dissolve rust more slowly, but if you’re patient, they work.
- Pour the rust remover solution in a plastic tub.
- Clean off any oil or grease on rusted metal before soaking.
- Then drop in the rusted item and walk away.
The Easiest Method to Combat Rust? Convert It.
If you can live with the look of a rough or pockmarked finish, rust converter can save you a lot of time. It kills the rust, prevents its spread and dries into a ready-to-paint primer. Buy it at any home center or auto parts store.
- Start by removing any flaking paint and rusty dust with a wire brush.
- Either spray on the converter or apply it with a disposable paintbrush.
- Let it dry for the recommended time.
- Pro tip: Even though the label says you can paint after it dries into a primer coat, I recommend spraying on a real primer, then painting.
- Apply a second coat of converter if you’re not going to paint.
- Pro tip: Don’t return the leftover converter to the bottle—it will contaminate the rest. Toss it in the trash, along with the brush.
Choose Between Liquid and Spray Converter
- Rust converter comes in brushable liquid or aerosol spray.
- Rust remover spray provides a smoother finish but doesn’t penetrate severe rust as well as brushable liquid.
Apply Converter After Wire Brushing
- Pour a small amount of converter into a cup and work it into the rusty patches with a paintbrush.
- Then smooth out the brushstrokes and let it dry.
- When dry, the surface will look rough but rust-free.
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Three Ways to Remove Rust from Metal Tools
Grind, sand or scour off the rust
Pros: No pockmarks and a smooth finish prior to painting. Complete project in a day. No waiting for chemicals to work.
Cons: Dirty, dusty, hard work. Requires power tools and lots of elbow grease.
Convert the rust
Pros: Easiest way to stop rust and prime in one operation. Less expensive than chemical or mechanical methods for removing rust.
Cons: Leaves a rough or pockmarked finish that’ll show after you paint. May not inhibit rust as long as traditional removal, priming and painting.
Remove rust with chemicals
Pros: Soaking removers can do all the work for you if the item is small enough. Spray removers greatly reduce the grunt work, but they require several applications and some scraping.
Cons: Long wait times for the liquid removers to do their job. Makes a huge mess. Soaking removers are expensive and can be used only on small items. The surface will still be pockmarked after the rust is gone.
Tip: Don’t think you can spray rust-inhibiting paint onto a rusty surface and get good results. The rust will bleed right through the paint and ruin your new paint job. You have to deal with the rust with one of the methods we show here. There’s just no way around it.
Prevent Rust: Prime First
- Choose a regular (non-sandable) primer if the surface is completely smooth.
- To fill in scratches, choose a sandable primer and lightly sand when dry.
- Use a filler primer to fill in pockmarks.
Prepare and Prime
- Clean the metal before priming.
- Apply the primer over the old paint and the newly sanded metal.
Prevent Rust with Paint and Topcoat
- Note: Several companies make rust-inhibiting paint. If you don’t find the color you like, try the paint department at an auto parts store.
- Spray on a final topcoat of clear gloss.
Apply a Clear Topcoat
- Allow the color coat to dry completely.
- Spray on a clear topcoat to extend the life of the paint.
Pick a High-Quality Paint
After all the nasty prep work, why risk another bout of rust by using cheap paint? Inexpensive paint contains less pigment, fewer resin binders and no rust inhibitors. Spend a few extra bucks on a premium rust-inhibiting paint. It will contain zinc additives that provide an extra measure of protection against future rust.
Brushing usually provides a better paint bond than spraying, but it leaves brushstrokes in the finish. However, spraying is tricky and if you stay in one spot too long, you can wind up with paint sag marks in the finish.
Whichever painting method you choose, seal the newly painted item with a clear topcoat. That’ll add to the gloss and dramatically increase the life of the paint by reducing paint oxidation.