With one natural ingredient, it’s easy to remove years of rust from antiques, artifacts, and tools.
A few months after I sold my first horse, I was walking through the pasture and found a shoe he’d lost sometime in the year before. Looking at it, I thought it would be a nice keepsake- and something I could use to create an equestrian project with sentimental value- it was covered with layers of rust.
I’d been experimenting all winter with using citric acid to clean rust off garden tools that I, in my easy distractability, tend to leave out in the elements. As it turns out, the basic combination of citric acid, water, and time completely removes rust from metal. I was pretty thrilled, especially after trying and mostly failing to remove rust from tools with caustic chemicals like CLR and The Works. A common ingredient in canning recipes, citric acid is an organic acid a little stronger than vinegar, depending on the concentration you mix it in.
2018 Update: I’ve loved reading your feedback on this article and how many of you have found this tutorial useful! A lot of the comments have suggested “just” using vinegar and soaking a little longer, but to have success with vinegar takes several weeks and LOTS of vinegar, so the math work out in favor of Citric Acid.
Supplies You’ll Need:
A bucket or plastic container large enough to hold your rusted object(s)
Very hot water
Pure Citric Acid – You can buy this wherever canning supplies are sold, however, the pricing on citric acid sold for canning has a huge markup. As of spring 2018, Ball brand citric acid is priced over $1/ounce but a 5 lb bag of food grade Citric Acid is 17¢/ounce.
My advice is to order online and don’t worry about having too much – it’s SO handy for cleaning- great for boosting dishwasher detergent, descaling coffee makers, getting grime off pots and pans, removing hard water stains, and general cleaning)
1. Scoop the powdered citric acid carefully into your bucket. I add about 1/3rd cup of powder per gallon of water, but you can use more or less depending on how rusty your object is and how quickly you need results.
2. Fill your bucket with very hot water and stir to dissolve the citric acid powder completely into the water. There should be no grit at the bottom of the bucket.
3. Place your rusty object in the solution. In this case, I’m de-rusting the horse shoe and I’ve tossed in some rusty bolt cutters since I’ve got project all set up.
The remaining rust in the grooves of the horse shoe bothered me, so I remade my solution and let it sit overnight.
DO NOT reuse the same solution for a second round. The chemical reaction that dissolves the rust changes the chemical makeup of the solution, making it ineffective for additional rust removal.
When you are pleased with your object’s new finish, dry it completely. The metal may seem “dirty” and rub off dark marks on your hands, this is normal for steel and iron with no protective coating. Make sure the object is totally dry (10 minutes in a 300-degree oven works great as long as the item is 100% metal with no plastic grips or other heat-sensitive portion) and then add a finish protectant.
You MUST protect the finish. If left uncoated, the unprotected metal will rust again almost instantly. You can apply clear coat / lacquer, or just spray with cooking oil and wipe away the excess oil.