A tool set left untouched through a monsoon can come out in worse condition than one used every week. Steel does not need to be worked to rust; it only needs damp air, and between June and September there is plenty of it. The good news is that the routine to prevent it is short.

Where it starts

Two places, consistently:

Inside the moulded case. The blow-moulded cases most sets ship in are close-fitting and unventilated. Put a tool away faintly damp, close the lid, and the moisture stays against the steel for weeks. Cases protect against knocks; they do not protect against humidity, and they can make it worse.

On bare cut and ground surfaces. Plated sockets and chrome-vanadium spanners resist corrosion reasonably well. Exposed steel does not — the cutting edges of a hacksaw blade, the jaws and pivot of pliers, the shank of a drill bit, the face of a hammer. Anywhere the protective finish is worn or was never applied is where you will see the first orange bloom.

The routine

1. Dry before it goes away. Wipe every tool with a dry cloth after use, particularly if you were working outdoors or near plumbing. This single habit does most of the work.
2. A film of oil on bare steel. A few drops of any light machine oil on a rag, wiped over pliers, bits, blades and hammer faces, leaves enough of a barrier. It does not need to be a specialist product.
3. Let the case breathe. Open the lid for an hour on a dry day every few weeks. If the set lives in a cupboard, that cupboard should not be an external wall that sweats.
4. Add a desiccant. Silica gel sachets — the ones that arrive in packaging — work well in a closed case. Replace them when they feel heavy.
5. Batteries separately, and charged. Lithium packs dislike both damp and being stored flat. Keep them out of the case, somewhere dry, at a partial charge rather than empty.

If rust has already started

Light surface rust comes off with fine abrasive and oil — a scouring pad or fine emery, worked gently, then wiped and oiled. Do not take an aggressive abrasive to a plated surface, because once the plating is through, that spot will rust faster afterwards than it did before.

Pitting that has eaten into the metal is permanent. A pitted socket will still turn a nut; a pitted blade or a pitted plier jaw has lost its edge and its grip, and is worth replacing.

A note on what we can and cannot help with

Corrosion from storage is not a manufacturing fault, and it is not something a return covers — ours or anyone’s. What we do cover is a tool that arrives already marked or damaged. Open the box when it reaches you rather than a month later, and if something is wrong on arrival, tell us within 48 hours with a photograph.