Do you have your tools stored in a non-climate-controlled environment, particularly if they are used in the field and exposed to the elements? If so, you know how quickly rust may form on your equipment.

A simple solution is to place pure camphor blocks in your toolbox or other tool compartment to prevent your tools from rusting. Camphor fumes will fill a drawer, cabinet, toolbox, or any closed compartment, then condense on the surfaces of the tools, coating them with a film just a few molecules thick. And because this film is an oil, it repels moisture and helps keep your tools from rusting.

Camphor is a crystalline oil derived from naturally occurring chemicals found in laurel trees or synthetically from turpentine. It slowly evaporates from its compressed block and then condenses on metal surfaces, insulating them from moisture. You need about 1 to 2 ounces of camphor per toolbox or cabinet, and you can expect the tablet to last 6 months to 1 year in a temperate climate. Be sure to keep the toolbox or cabinet space closed during storage. Avoid naphthalene (which is what they make most mothballs from these days).

Camphor is flammable — the flash point for camphor vapor is 150 degrees F. So use caution with tools such as grinders or anything that would get very hot or throw sparks. It’s also toxic if taken internally, so keep pets, children, and well… you from eating it.

You can buy Camphor from a source like Amazon. Don’t unwrap them. Instead, cut a slit in the individual block packaging and place it in the compartment.

You know it’s time to replace your camphor block when it has significantly shrunk in size, or its scent has disappeared, as this indicates it has evaporated and is no longer providing its protective benefits. A block of 100% pure camphor will gradually shrink and eventually disappear as the camphor evaporates and its odor vanishes.