Bolt Restoration

Now for a little info about rust: Some bolts have a fair amount of surface rust, but serious pitting hasn't yet set in. In some instances, rust can become so serious that it will weaken the integrity of the bolt. Portions of the threads will be missing, or the head size will be substantially reduced because of loss of material. In these cases, you will have to find a replacement. It would endanger your project to use a bolt in that type of condition again.

Rough and Tumble
Given that caution, next you'll need to choose how you will clean any rust or other discolorations and corrosion off the bolt. Most professional shops have what is called a "tumbler." This is a machine that does exactly what the name implies. All of the hardware is placed at once into a barrel or a bin and the parts are either rolled around or vibrated.


In less than an hour, the bolts are removed, looking very clean. The secret to these machines is what else is in the container. It is usually called "media" and it can look like small steel balls, or pieces of soft sandstone. As the container vibrates or rolls, the bolts constantly collide with these pieces of media. The collisions wear off all the rust and discolorations, but the media is soft enough to not damage the metal of the bolts.


A quick search of the Internet can show you that some smaller tumblers can cost about $250 and up. If you have a regular need for cleaning large quantities of bolts, then this might be a good purchase for you.

A Little Abrasive
Another much less expensive way to go is an abrasive pad. This round pad is easily adapted to a drill press chuck, and will perform much better than the often used-and-abused wire wheel. (A wire wheel can really remove a great deal of metal in short order, thus damaging the part in the process.) The abrasive pad is made of a coarse plastic, and it will wear out a lot faster than the bolt, so there is much less danger of destroying threads or other critical parts of the hardware. If you push really hard on the pad while it is running, you will start to see some sparks. This is your cue to let off a little, so that you are not removing any metal.