There is nothing quite as frustrating a rusted bolt that refuses to budge unless, of course, it's a snapping a rusted bolt because you didn't take time to treat it before trying to loosen it. Fortunately, there are solutions for removing rusted bolts that don't require brute force and that won't snap the bolt in the process. If you find yourself with rusted bolts, try these solutions to remove them safely and easily.
Clean the residue off the rusted bolt with a small brush. If the bolt is not corroded, a simple dry cloth will do.
Spray liberally with WD 40 and tap the head of the bolt with a screwdriver or hammer. This rust treatment will allow the WD 40 to penetrate the grooves on the bolt and will get more solution to the root of the problem.
Let the bolt sit for anywhere from 5 minutes for easy jobs and several hours for more complex jobs.
Use pliers to test the bolt. If it works itself loose, great! If not, apply WD 40 again and wait several hours. Still not loose? It's time to up the ante and try a tougher product.
Spray the bolt with PB Blaster Penetrating Catalyst. This rust treatment product is a penetrating oil that is designed to remove rust on stuck bolts and nuts. You can purchase PB Blaster at your local hardware store for under £3. It is available wherever auto repair parts are sold.
Wait five minutes and remove the bolt and nut with vice grips, which serve as screw extractors.
WD 40 is actually a penetrate and protectant. It is clean and easy to use and serves many purposes, among them is rust treatment. PB Blaster is a penetrant that is less versatile and has a stronger odour. Reserve PB Blaster for the really tough jobs!
Never apply heat to bolts that have been treated with WD 40 or PB blaster without thoroughly removing all traces of the solution.