If you need a good, cheap rust remover, here are three sure-fire recipes using everyday household ingredients. They are inexpensive, extremely fast-acting, and there are no harsh chemicals or fumes.
Remove Rust With Vinegar
Submerge the rusted object in undiluted white vinegar. If the object is too large to do so, liberally spray or dab vinegar over the rusted area.
Allow the vinegar to soak in for at least 30 minutes. If you're dealing with a lot of rust, a longer soak will probably be necessary. If that's the case, start with a couple of hours. Then, check on your progress.
Pull your object out of its vinegar bath, and use a brush to scrub off any remaining surface rust. An old toothbrush or nail brush works great for this. Then, rinse the object off, and dry it thoroughly.
Repeat the process if any rust remains.
Remove Rust With Lemon Juice
Mix Borax and lemon juice together to form a paste. You also can use baking soda if you don't have any Borax on hand.
Apply the paste to the rust, and let it sit for at least 30 minutes (longer for rustier objects). If the paste starts to dry out, just spray a bit of water over it to re-wet it.
Use a brush (a toothbrush works great) to scrub the paste into the rusted object. The scrubbing should lift the rust right off. If you still see any rust, just repeat the process. Be sure to rinse and dry the object thoroughly before you use it again.
Remove Rust With Baking Soda and a Potato
Slice a potato in half, and sprinkle the cut side with salt or baking soda. Then, rub the cut side of the potato over the rusted area. The acid in the potato will lift the rust, and the salt (or baking soda) will help scrub it away.
If you're trying to remove rust from your kitchen knives, plunge them into a potato, and let them sit while you go about your day. When you pull the knives out of the potato, the rust should wipe right off.
Wash and dry the object you cleaned before returning it to service.
Tips and Warnings About Homemade Rust Removers
Objects may appear black after being soaked in vinegar or lemon juice but should return to their original color after being rinsed in water.
These rust removers use mild acids and abrasives to remove rust. While they're less harsh than most store-bought rust removers, you should still take care when using them to clean antiques or other valuable items. Only you can decide when it's appropriate to use them.
Prevent surface rust by caring for your tools and equipment properly. Be sure to oil garden tools before storing them, hand-wash kitchen knives (instead of putting them in the dishwasher), and store belongings where they'll be protected from the weather.
Keep vinegar and Borax out of the reach of children and pets.