© 1998-2008 Joe Weaver

 

One of the more tedious and time consuming jobs in a "from-the-ground-up" restoration is to restore all the nuts, bolts & other fasteners to original or better condition. Often times it is considerably easier and far less time consuming to simply buy brand-new items (although locating all these can also be a time intensive and somewhat expensive task). Unfortunately, an exact or even suitable replacement isn't always available for a particular fastener, or if available the cost is often steep. Thus, if the restoration or refurbishing of some or all of your old fasteners becomes necessary or desirable, this edition offers some pointers to keep in mind.

The three most common ways that the nuts, bolts, and screws that were used on our Falcons were originally protected from rust and corrosion are; 1) chrome plating, 2) zinc or silver cad plating, or, 3) black oxide finishing. In addition, a few fasteners on these cars were made of stainless steel and required no plating or other finishes. It is possible for fasteners to be stripped and painted or powder coated, but the finish is easily damaged on the heads of bolts, nuts, and screws during the tightening process and the finish on the threads will definitely be damaged during tightening as well. This renders the fasteners easily susceptible to rust and corrosion, and lends a look of overall poor appearance. These problems occur far less with chrome, zinc/silver cad, or black oxide coatings since the coating is either electrically or chemically bonded to the surface of the part, or, as is the case in black oxide finishes, the finish is actually part of the part. All of these finishes are far tougher than paint or powder coatings as far as fasteners are concerned.

If your fasteners are moderately damaged or worse then you really have no choice other than to replace them with whatever you can find that will do the job. This is especially true if the threads are physically damaged or are moderately to badly rusted. Condition of the threads of nuts and bolts is critical to the performance of the fastener. If the fasteners are used for any type of structural connection the threads must be strong enough not only to tighten properly, but also to hold that part in place while under stress. Threads that are even just lightly to moderately rusted have already lost a great deal of their ability to tighten properly without stripping loose, let alone also hold a part under stress. Such deteriorated fasteners should never be used in any type of structural connection, but they can be used in nonstructural applications, such as attaching decorative trim, as long as there is enough thread left to tighten the fastener enough so it will not come loose. If, after careful inspection, you find that the fasteners are undamaged or only have minor damage, and/or have only surface rust, they can be restored to good as new condition.

Restoration Options

The word restoration means to return something to a state it was once in from a state it is in now. When fully restoring a 35 to 40 year-old car, we assume (with good reason) that many, if not most, of the fasteners we remove from such a car will be in poorer condition than they were when originally installed. Most likely they are not in a condition that we would want to install on this otherwise brand-new-condition car. Our goal is to remove as many ill effects of 40 years of use and abuse on these parts as we can. As mentioned above, depending on where the car has been driven over the years, a percentage of the fasteners will have been damaged or otherwise deteriorated beyond the ability to restore them. Cars that were driven in areas of winter weather where salt was used on the roads will have a much higher percentage of non-reusable fasteners than will a car that was driven exclusively in the desert southwest portion of the United States. As an aside, a car that had a lot of oil leaks and a greasy engine compartment and undercarriage will actually be a better candidate for a restoration car since the oil & grease helps protect much of the car and its fasteners from rust and corrosion.

Another area of concern is physical damage to these fasteners. Some damage occurs from the fastener being struck by something else, such as a bolt on the undercarriage being damaged from the car bottoming out on speed bumps or pot holes over the years. Other damage comes from less than optimal maintenance practices over the years such as using channel locks to remove a bolt or nut rather than using the correct size socket or wrench. Common damages as these include the stripping of phillips head screws by using the wrong size screwdriver, cross threading or over tightening bolts & nuts thus damaging or stripping the threads, using a hammer to force a bolt into a tight hole thus damaging the threads, etc.

If you need or desire to reuse a particular fastener, inspect it carefully to assess what if any damage you will need to correct before restoring the proper finish. Light damage to threads can be repaired with a thread restorer. A thread restorer is designed to "push" threads back up to their original position when they have been mashed down flat (such as if the threads had been hit with a hammer, thus flattening the raised threads). In this instance, a thread restorer should be used instead of a thread cutting device such as a tap or die since these will simply cut away the flattened portion of the threads, rather than restore them to their original height. One problem with a thread restorer though is that of fatigue hardening. All of us have bent a piece of sheet metal back and forth till it eventually breaks. This happens because metal, when it is stretched, hardens and becomes less elastic making it more brittle. When threads have been bent down once, and then bent again back to original position, they have lost flexibility and become more brittle, thus they have lost some of their strength. Before restoring damaged threads consider both the amount of thread damage and the application the fastener will be used in. In a critical area such as head or rod bolts in an engine, restoring damaged threads is not a sound practice, while using this method on one of several bolts that holds on a fender would probably be fine. Often, if threads are damaged, it is best to replace the fastener if possible. Light damage to the head of nuts and bolts can be repaired with light grinding or filing to remove rough or sharp edges. If the head is damaged such that you will not be able to tighten the fastener properly then attempting to restore it is fruitless. Rust and corrosion can ruin threads, the un-threaded shaft of longer bolts, washers, and even the heads of bolts and screws themselves. Rust is actually oxidized metal. Thus when rust is removed from a part, part of the original metal has also been removed. As mentioned above, consider the application the fastener will be used in before deciding whether to try and reuse one that has rust damage. Light pitting in bolt shafts, washers, and heads is generally of little concern unless the fastener is to be used in a critical area such as an engine. Moderate to heavy pitting of bolt shafts, washers and heads will seriously weaken the fastener and it should be replaced.

Once all the physical damages have been repaired, it is time to consider restoration of the correct or original finish to the fastener. Let's take a look at the different fasteners used on Falcons and the restoration considerations for each.

Stainless Steel: These fasteners generally are very durable and most often do not need to be replaced. Usually they can simply be cleaned up and reused. They can even be buffed up to a chrome-like shine. Of course, if these fasteners are damaged beyond reuse they will need to be replaced. There are many different grades of stainless steel. Some stainless alloys are stronger but are more likely to rust. Other stainless alloys are extremely rust resistant, but are not as strong. Most of the stainless fasteners in our Falcons are used for trim attachment (mostly in convertibles and hardtops) and seem to be of the type that is very rust resistant. These fasteners do not require a great deal of strength so resistance to rust and corrosion should be the main consideration here when looking for replacements. If reusing these fasteners, and a nice shine is desired on the exposed head, they can be polished with most metal polishing compounds (after filing off any sharp edges). I have also gotten a nice finish simply by buffing them up with "0000" steel wool as will be seen below.

Chrome Plated: Chrome plating is a very durable, long lasting finish. If you have fasteners that were originally chrome plated, you can simply buy new ones or have the harder to find ones re-plated at a chrome shop. Often however, as is the case with stainless, these fasteners can simply be cleaned up and reused. As with stainless, they can also be polished or buffed with "0000" steel wool to restore their original luster and shine.

Zinc/Silver Cad Plated: Zinc plating is an economical and fairly durable finish, however it is not nearly as durable or attractive as chrome. These fasteners are commonly available and almost any type and size of zinc/silver cad plated fastener can be located. There are, however, vast differences in the quality of these fasteners and the plating on them so expect to pay more for suitable quality. Lesser quality fasteners will dull and rust far sooner than higher quality ones. If you cannot find a fastener to replace yours with, zinc plating kits are available for use in your home shop. For example, Eastwood offers a tin-zinc plating kit which costs around $60. This is a simple electroplating process that uses two small "D" size batteries. To plate a part, it is stripped to bare metal, a wire from the negative side of the battery pack is attached to the part and it is immersed into an electrolyte solution. Also in the electrolyte is a strip of tin-zinc metal that is attached to the positive side of the battery pack. The current passing through this tin-zinc "anode" causes some of the metal to leave the anode, pass through the electrolyte solution, and (through electrical attraction) it is attached to the surface of the part. This is the process of plating. The parts that come out of the plating are coated with a dull gray film, and need to be lightly polished to restore the shiny look of the original zinc plating (in fact, Eastwood includes a tube of metal polish with the zinc plating kit). I had originally planned to purchase Eastwood's system and detail its use on this site. However, after looking over the all zinc coated fasteners I needed to replace or refurbish, I found that I could buy new replacement ones for about the same cost as Eastwood's system and not have to go through all the hassle of restoring each bolt and screw. As a result, most of the zinc plated fasteners that I removed from the car have been replaced with new ones. The only ones I didn't replace were ones that were still in excellent condition (such as ones that had been used up under the dash or in the trunk and were never subject to heavy moisture or road salts).

Black Oxide: Black oxide is a fairly durable, but not dressy finish. The finish is not applied to the surface of the metal as with chrome or zinc plating. Instead, the surface of the bare metal is brought into contact with a solution that causes a relatively stable oxide to form in the upper layers of the metal part. Thus, the finish is actually "part" of the part, and it forms a hard, durable surface on the part. Nevertheless, it must be noted that black oxide is still an oxide, just as is rust. Even though black oxide is more stable than regular old rust, it still needs some sort of sealer to keep moisture from seeping beneath the exterior oxidization and starting new rust below. Even so, this process is far prefered to simply painting or powder coating nuts, bolts, and screws. None of the black oxide fasteners I removed from the car were still looking good. All had some level of rust, some had bad physical damage, and others were rusted beyond reuse. I replaced all the black oxide fasteners I could. Where these fasteners were damaged beyond reuse and I couldn't find exact replacements, I went with the closest match I could find. There were, however, quite a few of these fasteners that were still in generally good condition, and which I was having a difficult time finding proper replacements for. As a result I decided to purchase Eastwood's "Blackening System" to refurbish them. The system costs around $30 and its use will be discussed in part two of this edition.

This is an example of physical damage to heads of phillips screws. These screws came from the chrome trim around the windshield and are chrome plated steel.

The new screw on the left in the photos above is a new chrome plated steel screw with a wax sealer on the threads. The screw on the right was removed from the stainless steel and chrome trim around the windshield. It originally looked to me as if the threads had rusted, but after seeing the screw on the left, and making a closer inspection, I realized the screw had originally had a sealer on the threads just as the one on the left. The sealer was used to seal the hole in the windshield frame so that rain/wash water would not get into the frame and rust it. Unfortunately, the head on this new screw is too large for the application, otherwise it would have been an excellent, exact replacement.

Many screw heads can be polished to restore luster and shine. One method is to use a metal polish. Another is to use steel wool to buff it. I used a drill for the buffing process. I gently tightened the threaded portion of the screw in the chuck (just tight enough to hold it but loose enough so the threads are not damaged) and then ran the drill while gently pushing "0000" steel wool on the face of the screw head till a good shine is restored.

These screws hold the convertible top latching brackets. The screw on the left has is as removed from the car. The one on the right has been buffed with steel wool and a drill as previously shown. The color tint on the polished screw heads are a combination of reflection and artifacts from JPEG compression--in real life the screw heads are bright and shinny.

Another comparison: These screws are chrome plated steel. The one on the right has been buffed with steel wool. I twisted some strands of the steel wool into a thread-like piece about the thickness of a piece of yarn and pushed it into the phillips slot while running the drill to clean and polish that area as well.

These are bolts for the structural cross member under the transmission that is only used on convertibles. A couple of the heads had received minor physical damage over the years but the threads were in excellent condition. After filing off rough edges on the heads and and media blasting the rust away these bolts were refinished with Eastwood's blackening system (using Eastwood's blackening system is covered in part two of this edition). The left photo shows them after being degreased with solvent and dried with compressed air. The right photo is after the process is complete.

This is what fasteners look like after media blasting. With all the protective finish removed they obviously need to be finished with some sort protective finish or they will begin rusting almost immediately, even from just the humidity in the air.

These nuts and brackets are used to secure the front bucket seats in place and are installed from the undercarriage after the seats are in place. The nuts were given a black oxide coat. The brackets were primed and painted, but they could also have been given a black oxide coat quite easily. However, since the brackets do not receive the same stresses that nuts & bolts do during tightening, paint or powder coat is probably the best choice for durability.

Overview

Discussion & Procedure

 

Restoring Nuts

Bolts & Fasteners

Part 1

This is the end of the Restoring Nuts, Bolts, & Fasteners Edition  Part 1

Part 1

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Feel free to save this page to your computer for your personal use and future reference--no other use is authorized without prior written permission from me. All illustrations from the 1964 or 1965 Falcon Shop Manuals used pursuant to permission granted by Ford Motor Company. Disclaimer: This site is not intended to instruct or teach anyone in proper or safe methods of working on or maintaining any type of vehicle or use of any tool and the author takes no responsibility for the use of the information contained herein.

If you have comments or suggestions, email me at joe@joesfalcon.com