On Sat, 29 Jun 2019 08:20:10 -0500, amdx wrote:

This will be a rarely used tool, and will be stored in my non-climate
controlled outdoor shed.

How do I best protect the surface

Rust is caused by oxygen and an electrolyte, which is usually water.

To keep oxygen and water away from the metal, cover the bare metal
surfaces with something so that the oxygen and water do not come into
contact with the metal. On a tool where the bare metal surfaces need
to stay bare, paint will not work. A layer of oil is often a good
option. Oil evaporates slowly, clings well to the metal and is
relatively easy to wipe off before use.

With metal objects that are kept at outdoor temperature, condensation
is the main problem (unless you leave it out in the rain). Metal has a
relatively high heat capacity, so when the weather changes from cold
and dry to warm and humid, the metal stays cold for a while, causing
condensation. If you can keep your tool slightly warmer than the
outside air, you will greatly reduce condensation and therefore
rusting. You don't need climate control. You only need to keep it
somewhat warm.
--
RoRo