Moisture is probably the single biggest culprit when tools start rusting. Exposed to the elements such as rain or standing water is quite obviously bad for tools but something not most folks think of is humidity. If your tools are in a damp basement they are just as likely to rust as if they were completely outside. Store tools in a dry location. Consider putting a dehumidifier in your basement not only for your tool’s sake but also for your health. Silica gel packs that you find in new shoe boxes are also great to put into the drawers of your tool chest.
Many woodworkers and machine shops can attest that a very fine layer of a water displacing coating can often be one of the best ways to protect your tools. While some may reach for their trusty can of WD-40 consider utilizing a product designed to maintain firearms.
Anybody that has ever worked around machinery knows that when new or newly sharpened bits come into the shop they have a wax coating. This wax coating helps maintain the edge on their bits but also acts as a barrier to the elements, inhibiting rust from forming on the sharp and exposed edges of crucial parts.
Sometimes if your tools are kept in an environment where the temperature fluctuates to the extremes your tools have a different temperature than the ambient air allowing moisture to condense on them. An easy fix to this is to keep tools in a location where the temperature doesn’t vary too much. For instance moving tools into your garage or basement which are both attached to your house is a better option than leaving them in the barn or shed in your yard.
Taking care of your tools begins with cleanliness. After a dirty automotive job or a sawdust laden woodworking project be sure to give your tools a wipe down.
Rust begets more rust. Bring back your tools by scouring the existing rust off and utilize the methods listed below.