Preventing Rust on Tools

You can discourage rust a number of ways. For my woodworking tools, like my table saw and jointer tops, I use Automobile Paste Wax. I put it on fairly heavily and often. It seems to work well. There are also cream waxes, but these contain some water, so I stick with paste.

Another excellent product for protecting woodworking machinery is Bostik Top Cote. This is a product specifically engineered for protecting the surfaces of woodworking machinery and lubricating the working surfaces to reduce wood-to-metal friction. As this was developed for contact with wood, it has no additives which might interfere with wood finishing.

For machine tools, Way Lube is the right thing. Keep unpainted parts of your lathe and mill covered with Way Lube. It's really inexpensive, often less than $12 per gallon.

For small tools, cutting bits, and stock, it is more complex. You really don't want to dunk a center punch in Way Lube or wax it, because you don't want it to be slippery. You also want the best possible protection up front, because it won't be renewed.

There are many commercial products that claim to displace moisture and prevent rust. Some common ones are WD-40, Starrett M1, LPS-1, and LPS-3. All come in aerosol cans, which is convenient although expensive and bad for our environment. All leave a film of light oily stuff on the metal. Other products are Sprayon Corrosion Supressant, Rustlick 631, CRC SP-350, CRC SP-400, Boeshield T9, Birchwood Casey Sheath, and Rust-X. Some of these products are petroleum based, while others seem to be wax based. However, they all prevent rust by keeping air and water off of the metal surface.

Not surprisingly, each product is claimed to do everything well and to surpass every competitor. Some claim that one works better than the others, but the real differences between these products are more related to their uses. For example, some leave a heavier, tougher coating than others. Some leave an easy-to-remove coating. Some are better in the presence of salt spray. But any of them will keep rust at bay as long as the work is well coated.

In general, I hear very good things from people about Boeshield T9 and I get poor feedback about WD-40. Perhaps this is because WD-40 is meant to do everything, while Boeshield T9 is specifically engineered as a treatment for long-term storage of materials. One common complaint about WD-40 is that it gums up mechanisms.

You can make your own rust protection coating by mixing 1 part Anhydrous Lanolin with 5 parts Paint Thinner. Just brush it on or dip the metal in it. You can get Anhydrous Lanolin from a pharmacy by special order. Dillon Case Lube is a commercial rust protection made from Lanolin and Alcohol. Many people have reported excellent results with Lanolin and Lanolin-based rust protection products. Contrary to popular belief, Lanolin is not perfectly safe even though it is natural. Some people have allergic reactions to it. In addition, it can clog pores and cause infections.

Another great technique for preventing rust is to protect the metal with a coating of zinc. This coating process is often called galvanizing. (Named after Luigi Galvani. Luigi Galvani is best known for experiments making dead frog muscles contract with electrical impulses.) Zinc is more electrochemically reactive than iron. Zinc prevents rust by oxidizing itself instead of iron. Many of today's cars are made with galvanized steel panels. These panels won't rust until after the paint is damaged and the zinc corrodes through to the underlying steel. You can buy Crown 7007 Cold Galvanizing Spray and other zinc based primers in aerosol cans.

Still another technique for preventing rust is to surround the metal with fumes from a material that discourages rust, such as Camphor (C10H16O) or Moth Balls. Some Moth Balls are naphthalene (C10H8) while others are paradichlorobenzene. Gun suppliers sell protective wrapping material and blocks which prevent rust by a similar technique. For example, Brownell's sells VPI Paper and Rust Blocks Vapor Tabs. Another good product is Permatex In-Charge Corrosion Inhibitor, a moisture absorber which also releases rust-protecting vapor.

Just storing your tools in a tight wooden box will discourage rust. Wood acts as a fairly good barrier to humidity and absorbs what remains. One person stored tools in side-by-side tool cases, one a Gerstner Wooden Case, the other a Kennedy Metal Case. After years of storage, the tools in the metal case showed surface rust while the tools in the wooden case were clean.

Dust can be a good magnet for moisture, so if you can keep dust off of your tools, you will discourage rust. A breathable canvas tarpaulin or fitted tool cover is effective. However, avoid a cover that goes all of the way to the floor. This will trap moisture and encourage condensation on your tool. Instead, just cover the tool down to the bench or chip pan.

Another great way to prevent rust is to put a dehumidifier in your shop. If your shop is a closed room or cellar, then a dehumidifier will be very effective. A dehumidifier will not be helpful in a drafty garage, but a garage may not be as humid as a cellar, either.