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This section summarizes the more common inquiries received by this site over the years. If you still have questions after reading our site (and checking the index!), you may be able to find an answer here.
Still can't find the answer? You might want to consider joining one of the tool discussion boards listed on our External Links page. These discussion groups have some very knowledgeable members who may be able to answer your question, or at least provide additional information. We monitor the discussion boards from time to time, and if there is some topic that enough people think should be added to the Alloy Artifacts site, we'll consider it as time permits.
A. We don't claim to be experts at tool cleaning, but will offer these observations as someone who has cleaned way too many tools over the years. When cleaning tools for display here, we try to remove all the dirt, grease, and rust that obscures the tool's features, while preserving as much of the original finish as possible. Obviously these objectives may at times be in conflict — for example, it's often not possible to remove all the rust from a tool while preserving the remaining original paint.
To simplify this section, we'll consider derusting as a separate topic (see below). The basic methods for tool cleaning are hand wire-brushing to remove large accumulations of dirt and grime, followed by wet sanding using WD-40 as a lubricant. For wire-brushing you'll want to have several sizes and types of brushes to handle flat surfaces, sockets, or recessed areas. An old style dental pick is another useful cleaning utensil, especially for removing dirt from cracks, slots, or hidden areas.
The wet sanding step serves to remove remaining dirt and grease, and will also polish the remaining plated finish. We use wet-dry paper with 300 or 400 grit, which works well for most tools. Note though that if your tool still retains some highly polished areas, it may be better to avoid sanding these areas, as even 400 grit paper will dull the finish.
Also at this step you may want to file down any burrs left over from hammering or other abuse of the tool; such burrs can result in cuts when the tool is used, and most mechanics would prefer to avoid this. (And of course almost everyone abuses their tools at some point.)
Tools with only small patches of the original finish remaining may require special cleaning. It's better to underclean a tool (or leave a rusty area) in order to retain some original finish, as the finish may be important in estimating the manufacturing date.
A. Anyone with an interest in older tools will have to deal with rust at some point — and generally sooner than later. Most tools are primarily composed of iron (as steel), and iron will rust easily unless protected by a finish or kept very dry. So given the need to remove rust, there are a number of methods that can be used, with various advantages and disadvantages.
Our preferred technique for rust removal is electrolytic de-rusting, an inexpensive method requiring only a battery charger, a plastic tub, and baking soda from your kitchen. There are fairly extensive resources on this technique available online, so we would recommend that you first do a search for "electrolytic de-rusting" and read through some of the articles. The remainder of this section will assume that you understand the basic concepts.
Once a tool has been treated in the de-rusting bath, it's important to realize that the rust hasn't been removed, but rather converted to iron powder. The iron powder immediately starts rusting again, but the important difference is that now the iron or rust powder can be brushed off easily with a wire brush. After the electrolytic treatment, the tool can be cleaned using the steps outlined in the previous section.
An important feature of the electrolytic technique is that it won't damage any bare metal or remaining plated finish. Thus whatever finish or marking detail is still present on the tool will be preserved during the treatment. However, most painted finishes will not be preserved by the electrolytic treatment, whether due to the slightly alkaline nature of the baking soda, or the presence of hydrogen bubbles under the painted surface.
Update 2024. When we first started with electrolytic de-rusting, we had an old-school battery charger that always provided 12-14 volts at the clip leads. However, most modern chargers don't do this; instead, they probe to see whether a battery-like device is connected before supplying any current. A tool lying in a bath of water and baking soda doesn't behave like a battery, and as a result a modern battery charger won't turn on the current.
The solution is surprisingly easy and is generally available at zero cost: most of our readers probably have boxes of leftover plug-in power supplies from defunct electronics such as cordless phones, routers, or other electronic equipment. These supplies typically provide 6 to 12 volts DC at currents of 0.5 to 1 amp, which will work well for derusting.
It's important though to check the polarity of the output with a voltmeter and make sure the tool gets connected to the negative side. We also recommend placing an ammeter in series with the supply so that you can verify that current is flowing into the bath. A current of 0.2 to 0.5 amps will work well for an overnight treatment.
Other Derusting Techniques. Another technique for derusting is the use of a commercial chemical product called "Evaporust". We haven't used this here, but have heard from reliable sources that it works quite well. Our main reservations would be with the cost and with the need to dispose of the spent liquid, which would be loaded with iron.
One more effective (but not recommended) method of rust removal is by sand or bead blasting. Sand blasting is very fast, but is very harsh on old finishes, and may even remove some stamped markings. Therefore this is not recommended for tool cleaning, except perhaps for items of purely utilitarian value.
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