How to prevent and treat rust on hand-tools and similar
Rust inhibitors — Protects one piece at a time
paste wax — Often used for table saw tables, partly because it also allows wood to glide over the table more easily. People swear by SC Johnson Paste Wax specifically, though this was unfortunately discontinued in 2021.
3-in-1 oil — Paul Sellers pretty much only uses this for his hand-planes. [2][3]
STA-BIL Rust Stopper — it beat the alternatives in this rust test
Boeshield T-9, originally designed to protect aircraft components, but is now used as a general-purpose rust inhibitor
WD-40 — WD stands for "water displacement". It isn't good for long-term rust prevention because it drips off so quickly. However, it can work well for preventing rust in the very short-term, right after a blade has been exposed to water.
Typically used for more specific applications:
camellia oil or mineral oil — Food safe, it's used to protect cooking knives. Camellia oil is sometimes diluted with liquid paraffin and/or mineral oil, both food safe. I haven't read anything about camellia oil dilution being a problem, however, food grade 100% mineral oil might be easier and cheaper to obtain.
Rust Prevention Magic — it's extremely long-lasting, however you have to use a heat gun to apply it
Bicycle chain lube, especially mountain-bike chain lube, is particularly tenacious under wet and muddy conditions. However, it is sometimes described as 'gummy' and can attract more dirt over time. Because of this, chain lube is expected to be periodically cleaned off and re-applied.
It comes in two varieties, depending on the season one is riding in — wet chain lube and dry chain lube. Wet lube is "stickier" and can hold on to dust and grime more readily.
designed for use with firearms:
CLP oil claims to "clean and protect" in one step, but there are some very valid criticisms of why that can never work well.
"CLP oil" can be a name for a whole group of gun-focused products
(A third possible option is 📔oxygen absorbers, since both water and oxygen are required before rust can form. However, I don't see any experienced folks suggesting that as a practical working solution.)
Removing rust
All rust must be removed before painting or adding some kind of rust-prevention.
Chemical solutions for easily removing any rust that has formed:
Note: Many rust removers has strong acids or other harsh chemicals, so if you don't have a workshop or garage to work in, you'll want to choose carefully.
Degreasers
Often these rust-inhibitor coatings can be cleaned off using degreasers. This is useful when you want to remove and then re-apply the rust inhibitor coating.
Most degreasers are hydrocarbons of some kind. Ones I like to use: