Popular Woodworking 2004-04 № 140, страница 96
A 'SHOCKING' WAY TO REMOVE RUST products will impede the finishing or staining of the wood. If you first cut a test piece with your freshly coated tooling to remove any excess rust-resistant compound, these products shouldn't affect finishing or staining. (See "An Unscientific Rust Experiment" on page 91 for what we learned about these products.) • A breathable canvas tarp or fitted tool cover can be quite effective. The cover keeps dust and pollutants in the air from settling on your tools. But try to avoid a cover that goes all the way to the floor, as that will just trap the moisture and encourage condensation. • A dehumidifier, which takes moisture out of the air, is a great way to prevent rust in your shop if it is a closed room or cellar. If you're in a drafty garage, it won't help, but the garage may not be as humid as a cellar, so you should be a bit safer out there. • There are some products on the market considered to be organic rust converters. These contain acid that converts rust to black oxide and polymers that bond to rust. Instructions tell you to remove all loose rust, paint on the product and let it dry. While these products have been known to work, oftentimes the resulting surface can be black and rough, and the converted rust might be less durable. • Manufacturers often use vapor-corrosion inhibitors to protect steel in sealed containers. These inhibitors are volatile organic compounds that condense onto steel and prevent rusting. Our Preferred Method Despite all these methods (each with their own positives and negatives), we've found in our years of woodworking, research, talking with experts and fighting rust ourselves, our favorite method is simply to use a tight wooden box to store small tools. Wood is a great barrier to dust, pollution and humidity. It might even contain a natural vapor-corrosion inhibitor. Dust is a huge magnet for moisture, so if you keep dust off your tools you will discourage rust. Of course, a toolbox isn't perfect - after all, you have to take your tools out to use them - but until a completely rustproof metal is made that can be used for woodworking, we'll stick with a tight wooden toolbox, tarps for the machines, regular cleaning and some sort of commercial rust inhibitor for the exposed surfaces. Get Rid of Rust To remove rust once it appears, there are some options. Surface rust is the easiest to eliminate, especially where excessive pitting has not formed, wrote Jeff Smith in a recent article for Hot Rod magazine called "Rust Busting." He said that while there are a number of rust-removal products, the simplest is a quick scuffing with some light-grit sandpaper. You also can use chemical methods such as Naval Jelly, which is a phosphoric acid that neutralizes light surface rust, making removal easier with an abrasive. Unless rust is chemically treated or physically removed, it will continue to spread. The problem is not just removing the rust, but also removing the sulfur or chloride ions in the rust that are absorbing water and accelerating corrosion by forming acids. Burleigh says it's best to remove what you can with whatever method you are most comfortable, then wash the object with soap and water to remove the soluble sulfides and chlorides. Dry it well, then add a rust pre-ventative on the surface. Adds Smith, of Hot Rod mag- We found a cool electrolysis experiment online via metals.about.com (thepontiac-transampage.com/rust.html) that seems to work well to remove rust from your smaller metal tools. All you need is a plastic bucket, a battery charger, some baking soda and an electrode. If you remember back to science class, a simple way to remove rust is to provide an electrical current - the rust will then move with the current. To get a current flowing, pour water into the bucket, adding about a tablespoon of baking soda per gallon of water. (Once the current is started, adding more soda will not make it go faster.) Put the piece of rusted metal into the water with the negative lead on it. (If it is part of a tool azine: "Fighting rust is not an easy job. Typically, shortcut cures and quick fixes only delay the inevitable, larger rust-repair job." These are just some of the best ways we've found to remove rust. There are many stories out there from woodworkers who have come up with solutions they say are great, just as there are many different products on the market. that has nonmetal parts, remove those parts, as you don't want to ruin them.) Attach the positive lead to the electrode, which could be a nail, a screw or baking pan (stainless steel works best). Place this electrode in the water a few inches away from the rusted metal (which must be completely submerged in the water), turn on the battery charger and watch as the rust goes away. When it looks like the tool is clean, remove it (use rubber gloves because the water is dirty) and take the leads off it. Scrub the surface with a warm, soapy pad to get the crud off it and see if the rust is all gone. If not, just repeat the process until you're satisfied. Then dry the objects and you're ready to get back to work. - MR Until someone comes along with the perfect solution, our suggestion to you is to find something that works (whether it's a dehumidifier, an airtight wooden box or simply buying new parts when the old ones get rusted over) and stick with it. But we'll keep our eyes and ears open, too. After all, as actress Helen Hayes put it, "If you rest, you rust." PW After attaching the negative lead to the piece of rusted metal, attach the positive lead to a sacrificial piece of metal.Then place this object in the bucket a few inches away from the rusted piece.After a while, remove the objects and see how much rust is gone.We think you'll be pleasantly surprised. popwood.com 93 |
