A handy way to restore rusty parts

For restoration of parts, I've been leaving them in Citric Acid solution. It's a great way to dissolving rust on things like brake calipers, hubs, etc etc before painting. As long as you don't mind a bit of a wait (i.e. 2-3 days) then you'll find nothing cheaper to get those parts back to bare metal. Best places to get the acid in crystal form is from places like Amazon & local supermarkets. It's mega cheap (usually £1.50 for a box that will be enough to make a decent sized bucket of solution). There's one trick to make sure the process isn't super slow, and that's to use very hot water, and then to try to keep it as warm as possible for as long as possible. Insulating the bucket and putting a lid on will help, or a heater element/heater mat could be used to keep the solution warm for extended periods. Every day it's good to remove the part to see how far it has cleaned up, and to wire bush any loosened rust to help speed things up. Once you're happy with the result, remove & wash the part immediately in fresh water, then dip it in a bucket of bicarbonate of soda to neutralize the acid, giving it a good brush. Dry the part with a hairdryer or heat gun to stop any surface rust forming, it may do if left to dry slowly. Wear gloves or you'll end up with hands smelling of rust for a while. The acid is the same stuff used for cordial drinks etc & so is food safe, and as such it only attacks the rust, so bare/clean metal is left alone.