Rust is a chemical reaction that happens when air and water meet metal. When tools don't get cleaned or stored properly, rust is the eventual result. When removing rust from your chisel, protect a wooden handle from moisture. Tape a waterproof covering over the handle and do not submerge it into any cleaning products. You may find just one of the following tips will remove the rust from your chisel.
Soak the metal section of the chisel in a container of vinegar overnight. Wipe the chisel with a clean cloth. Repeat soaking until the chisel is clean.
Treat the rust with an all-purpose spray-on lubricant and wipe it down with steel wool. Clean off any residue with a clean, dry cloth.
Combine equal parts of lemon juice and table salt on a plate or container and mix into a paste with an old toothbrush or a spoon. Rub the paste into the chisel with a dry cloth. Repeat applications until the rust is gone and wipe the chisel clean with a cloth.
Stir 1 tablespoon of black treacle into 118 ml (1/2 cup) of water in a container. Soak the chisel in the mixture, checking it every 24 hours until the rust breaks down. Dry the chisel with a cloth.
Rub the chisel gently with a fine-grit sandpaper to remove a light coat of rust.
Prevent rust from forming on your chisels and other metal tools by cleaning them regularly and storing them indoors. A light spray of all-purpose lubricant after cleaning may deter rust from forming. Wipe off the lubricant before each use.