Using horse feed additive called Molasses is a very kind way of removing rust from metal. I mainly use this on old bike parts but great for restoring old tools or any kind of corroded metal. I have found leaving them to soak in a 50/50 mix of molasses and water slowly eats away at the rust. Leave it for about a week and you get some stunning results.
Step 1: Create the Mix
Mix the Molasses with a 50/50 mix of water into a container large enough to take the parts you want to treat.
Step 2: Remove After a Week
Move the parts around in the container every other day and remove the parts after and week. Wipe with a clean dry rag. The results are impressive.
Step 3: Before and After
Here is a before and after shot of a bike I restored using this treatment.