I set up a molasses tank to assist in rust removal.
How does the Molasses Tank work, well you mix up 1 part of molasses to 10 parts of water, leave it for about a week by which time a terrible scum forms on top of the solution. Remove that scum and throw it away and your molasses is ready to use. This solution is not an acid in any way, what removes the rust is a type of algae which feeds on oxygen. Rust consists of hydrated iron(III) oxides Fe2O3•nH2O and iron(III) oxide-hydroxide (FeO(OH), Fe(OH)3). Rust is a good source of oxygen for the algae.
A word of warning, DO NOT put die-cast or items containing zinc into the solution or you will find that they haves disappeared. If you put brass or bronze items into the solution, do not leave them for more than 2 to 3 days as the algae will eat out the zinc and turn the brass back to copper.
Into the molasses I put almost every small part. Here two similar items, one piece done and the other before treatment.
After leaving them to soak for a couple of weeks I removed them and after pressure washing each piece I wire brushed them and this was the result.
Hundreds of pieces were soaked for varying times. Sometimes they went back into the solution many times after being wire brushed to obtain a rust free item.
Regards Rick.