Can oiling keep tools from rusting?

Question

Even stainless-steel can rust, and I've seen axes and saws that were visibly rusted. I've been told that wrapping the metal parts of the tools in oiled paper will prevent this.

Can oil really be used to prevent rust creation? And is there a difference between types?

From a chemical point of view, I would say it makes sense: The oil and paper wrapping could prevent the access to oxygen and thus prevent oxidation. But I would imagine vegetable oil is vastly different from types meant for engine greasing.

Answer 1

It can, yes - by keeping water and oxygen away it can greatly slow or prevent the oxidisation process from occurring.

However, I wouldn't necessarily advise it as the best approach. Instead I'd advise making sure tools are clean and thoroughly dry, then storing them in a cool dry place (unless the manufacturer recommends otherwise of course.)

There's two main reasons for this. Firstly, oils can go rancid, which means they're a) not as effective at keeping out moisture and oxygen and b) they smell absolutely foul. Secondly, some oils - notably vegetable and mineral oil - can leave a horrible sticky residue which is a nightmare to clean off.

There may be corner cases with situations or bits of kit that makes it worth it, but in general I'd say it can do more harm than good.

Answer 2

The type of oil surely matters. Within petroleum products, thick, waxy Cosmoline has proven to be effective, but it's not nice to remove. (I've never personally used it for this reason.)

I have recently learned of and started using Fluid Film. It has an unusual (to me) wool-lanolin base. I have limited experience with it and I have not yet conducted my own testing but I have seen several positive reports. You can find tests of varying veracity with a simple Web search.

This is getting further off topic as none of these products are simple oil as far as I know, but here is a salt spray test that includes Fluid Film. Fluid Film is basically non-toxic¹ and performs as about as well as any of the "Soft Film" products. Compare the MSDS² for the highest rated "Water Displacing Soft Film" in that test, CRC Protector 100. For this reason I use Fluid Film for knives/tools that may contact food.

_{1. "Ingestion of this product is not regarded as a significant health hazard likely to arise in normal use."}

_{2. "Harmful or Fatal if Swallowed."}