Resto Series Number 1: Bodywork Basics

By Eddie Paul

Bodywork consists of all of the steps required to repair a damaged panel up to the paint prep stage. These steps include assessing the damage, grinding, repairing or reshaping the metal, molding and filling, and sanding the surface until it’s smooth and even with the rest of the panel.

The Logic Behind Body Repair

Brian was restoring one of the 1950 Mercs used in the movie Cobra that we had
originally built for the film when he stumbled on a bad area in the body. 
The first step was to pull out all the newspaper that was added by some “amateur”
body man as filler to help give some support to the Bondo that was used to
hide the rust hole. This is a perfect example of how not to fix a rusted area.

    Most automobile bodies are manufactured out of flat, annealed steel plates that are stamped into their final form using large 300- to 500-ton presses. As the metal is pressed into the final shape by its solid steel male and female dies, it undergoes a bit of work hardening that helps the metal maintain the refined shape that was intended for the conclusive product. The piece is then welded or bolted together with other stamped pieces to provide the entire automobile with a stronger overall shape. Every automotive body as a whole has enormous structural integrity as well as refinement of design and function. Each gentle curve and subtle body line gives the body as much added strength and rigidity as it does styling.

    In a perfect world, the autobody repair and refinishing industries would not be needed. Cars would never break or rust out, drivers would never have accidents and paint would last forever. But the truth is that auto repair and refinishing are big businesses in which many people are able to make good livings. Autobody repair, customizing and painting skills are valuable commodities in the automotive workforce.

    Bodywork and painting tools and materials have evolved over the years in an effort to streamline the various repair processes and make each step easier, faster and more efficient. Where once the most sophisticated tools of repair consisted of a tape measure and a straightedge, shops now use computerized equipment with digital accuracy. The refinishing industry has also seen much change over the years. Still, in spite of the many changes, technology has not been able to eliminate the need for basic repair skills for fixing dents and spot painting panels. Much of the same tools and techniques that have been used for decades are still the best and only way to get a job done.

With the paper and some of the filler removed, the damage was evident and
 a plan of repair could be initiated.

    Anything from a wayward shopping cart or a careless swing of a car door in the grocery store parking lot, to a mild fender bender on your way to or from the store can result in a blemish to an otherwise perfect car. Depending on the severity and force of the impact, the metal could have just pushed inward slightly with only a small crease around the perimeter of the indentation. Mild damage such as this can occasionally be repaired with only some light hammer-and-dolly work, or sometimes with just a gentle push from the backside of the panel. Unfortunately, however, easy fixes are rare. Whenever the shape of metal is forcibly changed, the result is a modification of the metal’s properties at and around the area where the reshaping, or damage, has occurred. If a damaged panel exhibits any sharp bends or creases where none existed before, it’s a sure bet that the metal is stretched and cannot be pushed or tapped back into shape without getting into some refinishing work. But before we get into the process of repainting, there are several techniques and tools to cover as we discuss all of the things you’ll need to know about the basics of auto body repair.

    The need for basic bodywork, or as it is also commonly referred to, “dent repair,” has been around ever since the first steel-bodied cars began to take the place of the horse and carriage. It’s very likely that the art of metal restoration dates back even further than the automobile. For instance, I’m sure that any knight in shining armor surely would not have entered into battle with an unsightly indentation in his steel suit; so the village blacksmith or whomever was responsible for bumping (“bumping” is an antiquated term for straightening or hammering sheet metal back into original form) the metal back into shape could have very well have been the medieval precursor to the body man of today. Think of the metal armor that was effectively pounded into shape back when hand tools consisted of no more than a big hammer and an anvil. How did these craftsmen shape metal with such crude tools and no formal training? And how did they make repairs?

Cutting a few small pieces of metal and MIG welding them in place only
took about 10 minutes. The area was as good as new after a very thin coat
of filler was applied. We matched the gauge of the original car body with s
mall patches. If the patches are in an area that may rust again, we
sometimes make them out of a thicker piece of metal.

    The point is that you will not need a lot of fancy equipment to repair a dent in a car. All dealership body shops and many independent ones have state-of-the-art computerized body repair equipment that requires comprehensive training and regular updates in order to use. A heavy collision repair specialist must be certified to use these types of systems, but the reality of basic body repair work is that nothing “high-tech” has replaced the knowledge and experience that a real metal man must have. Becoming a good body man is not about having a lot of fancy tools; it’s about knowledge of how to work with metal, how to shrink it, stretch it, shape it and weld it; and most importantly, how to “read” a panel by feeling it with your hand.

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Getting “The Feel” of Things

    To sum things up in a few simple words, you can’t fix what you can’t feel! Therefore, the ability to feel the slightest irregularity on a vehicle’s body is the most important acquired skill of basic body repair. I’m sure that everybody’s individual sense of feel is different and some of you may not have as much sensitivity as others. But believe it or not, there is a technique to feeling a panel and, with a few tips, you, too, can get the feel of flat panels, contours and irregularities.

    Feeling, or reading, a dent is a skill that one acquires through time and experience. If you can see a dent, chances are that you can also feel it. However, as a dent repair progresses, the visual element diminishes as the panel gets closer and closer to its original shape. The eye can be deceived by any number of things, so you must rely on feel.

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Investigate The Damage

    How was it hit? From what direction? How great was the force of impact?

    These are some of the questions that a good bodyman must be able to find the answers to. Not unlike a crime scene investigation, this involves taking a close look at the damaged panel and trying to figure out how it happened. There are a lot of fascinating police dramas on television that take you into the world of forensics. Well, analyzing a dent to determine how to repair it requires a bit of autobody forensics as well. A good body man must always perform this step of diagnosis before blindly jumping in with the hammer and dolly. Although I specialize in custom work on cars and motorcycles, I have also been doing body repair work for as long as I can remember. Over the past three decades or so, I’ve gone through hundreds of employees, so I have seen the gamut of bodymen, from the “best” that can fix a dent without using any fillers to the ones that can turn a minor dent repair into a disaster by overworking the area and stretching the metal into a useless piece of scrap. Guys who start pulling and hammering before carefully analyzing the problem are the ones who rely heavily on plastic filler to fix their mess.

On this famous car we needed to save the severely rusted-out hood, as it
was the custom one we built for the film Cobra. The metal was replaced
and hammered into shape and then worked to a finish with a thin coat of filler.

    I used to have what I call a “flight of the imagination” theory that if you could tell exactly how a car was hit, and could reverse the damage in the exact opposite direction with the same force that made the damage in the first place, you could, with one pull, take the dent out of the car. In theory, this would work, but in practice, it does not because most bodymen are much too quick to start beating a dent out without first reading the dent to see exactly how it happened.

    Was it a direct hit perpendicular to the cars axis, or was it a glancing blow or even a combination of a direct hit that glanced off of the panel? Any principle damage to a car causes collateral damage to a car. For example, if the rear fender is hit, it will affect the door gap, trunk gap and a lot of the body alignment. It can cause unseen damage to the frame or even to the suspension and drive train. A small dent can have great underlying damage potential, so don’t just look at the dent and think small. Look around and see what else might be affected by the impact. Force is the power or energy that the car was subjected to that caused the dent. You can figure that it’ll take roughly the same amount of force to pull the dent out of the car that it took to make it. This may sound simple, but keep in mind that there are numerous factors to take into consideration. In other words, you can’t just slam the backside of a dented fender and expect to fix it.

    It’s safe to say that no two dents are identical. For this reason, it’s virtually impossible to categorize dents. Therefore, a bodyman must be prepared to deal with something new and unexpected when it comes to repair work. Learning the basics of bodywork is not a process that is ever really complete. But what you can learn here is that the key to fixing a dent is being able to analyze the damage and figure out how best to reverse the process.

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Sponsored By:

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Howell's Sheetmetal CWI

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