Rust may be inevitable, but today’s liquid removers make short work of the stuff. For the most part, they’re mild water-based chemicals; most use some form of chelation technology (their components surround and bond to iron particles). Those bonds to the rust are so tenacious that the stuff loses its grip on the metal and literally falls off. This saves you a lot of elbow grease because you don’t have to grind away rust or scrub the corrosion off using a wire brush. Simply soak the effected part in the remover—or brush on the gel—before you wipe the part dry. Then proceed with your next step, such as painting the steel or applying a light coating of oil, wax, or anti-corrosion sealant to inhibit further rust formation.
(If you want to know more about the fascinating process of how metal rusts and some of the tools, materials, and equipment that you can use to deal with it, we’ve written about it before.)
How We Tested
To test liquid rust removers, we turned to one of the nation’s preeminent experts on corrosion, NASA’s Corrosion Technology Laboratory at the Kennedy Space Center. The lab advised us on test methods and prepared our test samples for us. Each test sample consisted of a 4 x 6-inch piece of carbon steel, with a piece of C channel welded to it. The samples looked odd, but they would allow us to test the removers on a flat surface, an inside corner, an outside corner, and a weld. NASA then took each of those and submitted it to its salt water rust bath, ensuring that each piece was uniformly corroded.
From there, we immersed each test specimen in the remover (or brushed it on), following the manufacturer’s directions. After we wrapped up those tests, we tried the removers on hand tools and hardware. With NASA’s advice, its generous contribution of samples, and our own use, this was about as thorough a test as can be performed. Here’s how each remover performed.
Advertisement – Continue Reading Below
Evapo-Rust says it traces the development of its product to its work on behalf of America’s military, to make a safe industrial-scale method of rust removal. After using the ER012, we’re inclined to believe that claim. Evapo-Rust is effective and quick. After six hours of soaking, the test blank was quite clean. After 12 hours, it was spotless, including the corners and the weld. We noticed minor carbon deposits had leached out of the steel, but with a little effort we managed to wipe these off using rags and a plastic scouring pad. This isn’t a function of the rust remover as much as it reflects the degree of carbon in the steel or the weld metal. Some steels will emit more carbon in the rust removal process than others. Bottom line: This is a fine and effective product.
Bull Frog 94237
Bull Frog’s thick, honey-like consistency provides good cling, allowing it to work well on vertical surfaces or parts that are too large to dip. Brush it on and leave it alone for several hours. We find it stays moist and effective the entire time (of course, that will vary depending on how warm and dry your shop is and the humidity where you’re working). If you notice that the material hasn’t completely removed the rust, a little scrubbing with a plastic scouring pad is all you need to remove any that remains. It was also the only product we tested that prevented flash rusting (which can happen within 20 minutes of treatment if you don’t prime or seal quickly) by using a Vapor Corrosion Inhibitor (VCI) that bonds electrochemically with the freshly cleaned surface. The VCI emits a corrosion-inhibiting vapor that provides long-term protection to bare metal.
Workshop Hero WH003226
A six-hour soak in the Metal Rescue bath will get your part clean enough to finish the job with hand tools. Let it soak for 24 hours, though, and when you remove it, you find a part that’s nearly pristine. If you can afford the extra time to allow the part a thorough soak, Metal Rescue is a good choice. The brand’s parent company, Armor Protective Coatings, provides a variety of solutions to keep parts rust-free. For example, it also offers a spray-on coating that inhibits rust, plastic films, and treated paper bags that have the same VPI technology as the Bull Frog 94237 above. By emitting a vapor that retards corrosion, these products protect bare metal over the long term. That way, you can buy a complete system consisting of rust remover and long-term protection materials.
Best On Concrete
Unrust Rust Remover Starter Pack
Dissolve this packet’s contents in a gallon of water and you have a moderately effective bath to soak parts (but it requires at least eight hours). Where the mixture really shines, though, is in getting iron stains due to irrigation water off of concrete sidewalks and driveways. In that case, pour the gallon mix into a garden sprayer, pump it up, spray it on, let it act, and then rinse it off. You can also dip into a gallon bucket using a paint roller attached to an extension pole. Roll the mix on, let it act, rinse it off. The same method applies to vertical vinyl fencing that has been stained by iron-containing irrigation water.
This content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. You may be able to find more information about this and similar content at piano.io
Advertisement – Continue Reading Below