Forget WD-40: The Protective Coating That Keeps Rust Off Your Tools

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Everything that's made of metal rusts, especially things like garden tools that are typically left outside or in uninsulated sheds or garages. Rust makes lopping and trimming tools more difficult to operate, and by creating a high-friction surface, it does the same to digging tools, like shovels and hoes. You can try oiling your tools to control rust, but if you want longer-lasting protection, you need a lubricant that leaves a hard, slippery, wear-resistant coating, which WD-40 and most of its substitutes typically fail to do. Boeshield T-9 Waterproof Lubricant and Rust and Corrosion Protector, which was developed by Boeing for the aviation industry, is a reasonably priced lubricant that can do that. 

The original purpose of Boeshield T-9 was to lubricate the wings and landing gears of airplanes, and anything that can perform critical functions like that can probably keep a pair of pruning shears operational. Over 5,000 users on Amazon (where a 12-ounce aerosol can sells for $22.99) say that it can, giving this product a 4.8-star rating, with only 15% rating it less than 5 stars. User Dr. B comments: "T-9 is nothing short of a magic elixir for anyone who values their cast iron tools, and it has become an indispensable part of my workshop maintenance routine." The component of Boeshield T-9 that sets it apart from other lubricants is paraffin wax. It leaves a sticky coating that dries and hardens to provide a hard, dust-resistant, and slippery surface. 

Like WD-40, Boeshield T-9 contains water displacement chemicals that allow it to dissolve light rust, but it isn't primarily designed for that. It's designed to prevent new rust, so before you use it, you may have to mechanically remove heavy rust or dissolve it with another product, such as Boeshield Rust Free. When you've cleaned the metal and sprayed a coat in T-9, the surface will feel sticky at first, but as the product dries, the film will harden and the stickiness will disappear. You can use T-9 on stationary tools, moving parts, chains, and anything made of metal. 

According to the product specifications, T-9 is safe to use around paint, rubber, fiberglass, plastic, and vinyl, but that doesn't mean you shouldn't aim carefully when spraying it. Cchase, a bike repair pro posting on Bob Is the Oil Guy, complained that it was as hard to remove as paint once it dries. He discovered the problem when he used the product to lubricate his bike chain and inadvertently got it on other parts of the bike. Despite criticizing the products as being messy, however, he acknowledged its effectiveness as a lubricant.    

One other benefit of Boeshield T-9 is that it is free of chemicals with the potential for long-term harm to the environment, such as Teflon and fluorocarbons. It is flammable and a skin irritant, however, so it's important to wear gloves and keep away from open flames.