Automotive Bodywork and Rust Repair

by Matt Joseph

  not. Fortunately, in autobody metal

  repair

  area

  to

  the

  minimum

  Of course, it is possible to over-

  work, most people engage in the con-

  necessary size to get it done with a

  analyze or over-plan your work, to

  tinuous improvement of their skills,

  good result. In the case of the dent,

  the point that these approaches

  tools, and equipment.

  accurate analysis allows you to move

  become paralytic. Then, all that you

  One great resource that can be

  the least amount of metal that com-

  can see are cascades of hypothetical

  yours without any investment in

  pletely unlocks the undamaged

  problems, leading to catastrophe.

  tools and equipment is planning

  metal configured into the dent. This

  Good planning in body metal work

  your jobs. This sounds simple, and

  results in the least possible collateral

  stops short of that kind micro plan-

  for the most part it is. However any-

  damage to adjacent metal from

  ning, but goes deep enough to avoid

  one can let a job progress with little

  stretching and deforming areas that

  most foreseeable problems.

  or no advance planning, and end up

  do not really need to be worked.

  with uncertain results. Take two sep-

  The alternative to this kind of

  Inherent Advantages

  arate examples: repairing a rust-out

  planning is to throw yourself, willy-

  and repairing a dent. You can plan

  nilly, into a job and let one move

  There are certain propositions in

  these jobs minutely, probing the

  dictate the next, with little or no

  bodywork that amount to inherent

  extent of the rust-out and analyzing

  planning at all. Sometimes, this

  advantages in the nature of this work

  the nature of the dent. Then, you

  happens when a job seems so sim-

  that you can leverage for your bene-

  can formulate the best and most effi-

  ple that it doesn’t require any plan-

  fit. Here are two simple ones: Auto-

  cient ways of dealing with these jobs. ning. Often, this approach results in

  mobiles are mostly bilateral, and you

  In the case of the rust-out, this

  letting one mistake or miscalcula-

  can only see one side of a vehicle at

  involves welding in enough new

  tion dictate the next, as the job

  a time.

  metal to do the job completely, and

  careens toward disaster. It sounds

  That means that their left and

  so that it will be durable, while

  pretty dumb, but we have all been

  right sides are, or should be, mirror

  avoiding excessive heat buildup and

  there, in one way or another, and I

  images of each other. And that can be

  resulting distortion in the panel. In

  claim no exception to that dubious

  a huge advantage when you have to

  this case, that means keeping the

  distinction.

  repair or fabricate a shape for which

  AUTOMOTIVE BODY WOR K AN D R UST R E PAI R

  23

  CHAPTE R 2

  metal on the side where it will be

  used, it may not exactly match the

  one on the other side from which the

  pattern was created. That is not a

  problem because, after they are

  mounted, you never see or compare

  the two fender skirts at once.

  This brings up another point

  about human perception. People often

  tend to see what they expect to see.

  About 90 percent of all lightning

  strikes originate from the ground

  upward. But we tend to see it as strik-

  ing down. Why? Because we expect to

  see fast-moving things fall out of the

  This fender skirt illustrates the bilateralism of auto bodies. The one on the

  sky, not rush up into it. The same rule

  other side of this Packard is a mirror image of this one, and can be used to

  of perception applies to bodywork.

  pattern it. In this case, absolute bilateralism is not necessary because you can

  People expect to see most panels

  never see both fender skirts at once.

  formed into smooth arcs and contours,

  with sharper arcs, creases, or angles at

  you have no pattern. With a panel

  translating bilateral measurements

  their ends, and in some other areas. If

  like a badly damaged hood or roof,

  enables you to build models of

  you are able to make metal work into

  you still can determine its proper

  shapes that you need to fabricate

  those arcs and creases with reasonable

  final shape because you have the

  from scratch.

  but not necessarily perfect accuracy,

  other side for a model. Of course, you

  The inherent advantage of vehicle

  your work will pass visual inspection.

  have to translate the measurements

  bilateralism does not end with symme-

  Put bluntly, some of the best

  of the good side into its mirror image,

  try, but couples with another inherent

  bodywork that you are likely to see

  but this is not always difficult. For

  advantage of vehicle configuration

  would never pass a close dimen-

  example, if 5 inches back from its

  that may make your work easier. You

  sional inspection with calipers, dial

  front, the outer edge of a hood falls

  cannot see both sides of a vehicle at

  indicators, or laser scanning. Fortu-

  13⁄16 inches from the high point at its

  the same time, unless, of course, it is

  nately, that is not a problem because,

  center, it should do this on both its

  parked alongside a mirror, or some

  after it leaves the factory, it doesn’t

  right and left sides. When you are

  other perfectly accurate reflecting sur-

  have to pass that kind of rigorous

  removing a dent from it or sectioning

  face, which is extremely unlikely.

  dimensional inspection.

  in a rust repair, this kind of informa-

  The fact that you can only see

  This is not an invitation to do

  tion is priceless. Of course, you usu-

  one side of a car at a time can be an

  sloppy work that meets the low stan-

  ally have to plot many points this

  enormous advantage if you have to

  dard of close enough. It is simply

  way for this trick to be useful.

  fabricate, or massively repair, an item

  recognition of the reality that the

  When you inspect your progress

  like a fender or fender skirt. You can

  human eye does not see things with

  restoring that hood, you can use that

  use the fender skirt from the other

  perfect dimensional perception of

  measurement, and numerous simil
ar

  side to translate and create a pattern

  accuracy.

  measurements, to know how to pro-

  for the one that you fabricate. In this

  ceed in the job, and to confirm when

  case, the final fit of the fender skirt

  Divide and Conquer

  you have it right. The bilateralism

  has to be to the metal on the side

  and symmetry of the hood informs

  where it belongs. But patterning from

  Most bodywork jobs can be

  your eye when the panel is right, but

  the other side will get you started on

  divided into tasks and subtasks. In

  the use of bilateral measurements

  the shape. After you have made the

  many cases, these can become

  helps you to get there. In some cases,

  actual piece, and blended it to the

  routine. What looks like an incredibly

  24

  AUTOMOTIVE BODY WOR K AN D R UST R E PAI R

  LI M ITS OF MATE R IALS, EQU I P M E NT AN D S K I LLS

  difficult repair, or a massively

  challenging fabrication, often can be

  approached this way, as a series of

  simpler tasks. For example, faced with

  having to create a complex fender

  patch to repair a rusted or hopelessly

  damaged area, the job can look

  impossible at your skill and equip-

  ment levels. But when the piece that

  you need to fabricate is analyzed for

  its exact content, you may discover

  that simpler tasks that you have mas-

  tered will add up to its completion.

  Let’s say that this section of an

  old fender has some crown, a

  dropped edge with a narrow bead,

  and a wire folded under the edge of

  the bead. That looks intimidating.

  But by using body hammers and

  mallets, you can form the body of the

  Forming the new metal to section in rust repairs for this fender is a complex

  repair area on a shot bag, or on a

  job, but it can be broken down into multiple simple tasks. Always consider

  wooden form that you create for that

  approaching complex jobs as several simple tasks.

  purpose. You can model and cut

  metal into the shape of the edge and

  you can wrap it around the edge wire.

  Then, you can align and weld the

  folded bead area to the larger piece

  that you have made. Sure, it’s simpler

  in the telling than it is in the doing.

  But the fact remains, this seemingly

  complex job can be divided into

  areas and tasks that are relatively sim-

  ple, and then assembled into a fin-

  ished piece that is complex.

  Would it be better to make the sec-

  tion described above in one piece? Prob-

  ably it would. And someday you may

  have the experience, skill, and equip-

  ment to do that. But before that day

  arrives, it is good to know that you can

  build complex shapes out of simpler

  ones that are already within your com-

  petence. Later, when you achieve great

  expertise and proficiency in this work, it

  Always record the exact construction of panel areas that you need to replicate.

  will be fun to remember the cumber-

  Written notes and photographs may help enormously, after you have cut out

  some approaches that you once had to

  and destroyed original sections of these panels. Without good records, what

  take to do jobs that you can now do

  seemed easy to remember may become difficult as time passes.

  much more simply and much better.

  AUTOMOTIVE BODY WOR K AN D R UST R E PAI R

  25

  C H A P T E R 3

  TYPES OF JOBS

  This chapter looks at the core tasks

  the mid 1930s, this information was

  used in damage and rust repair jobs,

  issued as a booklet of a little more

  and at some of the most basic strate-

  than 100 pages, titled The Key to

  gies and skills needed to master them.

  Metal Bumping, by Frank T. Sargent.

  What you need to know starts here.

  In various formats, this book has

  been more or less continuously in

  Damage Repair

  print since then, with reprints of the

  1953 edition still available.

  The analysis of crash damage is

  That book revolutionized auto-

  the first and often most critical step

  body repair by putting theory under it,

  in repairing it. Before the 1930s,

  and by specifying a series of standard

  there was little or no literature avail-

  procedures to guide it. It is, simply, the

  able to indicate standard operating

  Holy Grail of sheet steel repair practice.

  procedures for this crucial first step in

  While much about the autobody crafts

  repair. While some practitioners—

  has changed in the more than 75 years

  body and fender men—may have

  since The Key to Metal Bumping was first

  had fairly modern approaches to

  published, everything in it is still accu-

  repairing deformed metal, most of

  This reprinted version of the 1953

  rate, relevant, and useful. Anyone seri-

  them did not. They simply hit metal

  edition of The Key to Metal Bumping

  ously pursuing the sheetmetal craft

  with hammers against dolly blocks

  is still available today. Its advice

  should examine a copy of this trove of

  and hoped for the best, and that

  regarding the basics of analyzing

  body panel wisdom.

  everything would come out right. If

  collision damage and moving metal

  The nugget of The Key to Metal

  metal was high, they hit it down. If it

  remains clear, to the point, and useful.

  Bumping is that body damage con-

  was low, they hit it up. In this

  sists of direct and indirect compo-

  process, they often inflicted terrible

  company issued catalogs that con-

  nents. The first is deformed metal

  additional damage to metal, like

  tained the first easily accessible sci-

  that is displaced beyond the elastic

  stretching it and cracking it, but they

  entific information on sheetmetal

  limit of the panel material, and that

  managed to hide this damage under

  repair. This methodical approach to

  is holding the indirectly damaged

  the filler material of that period, lead.

  repairing damaged autobody panels

  metal out-of-place. Relieve the direct

  All of that changed in the early

  revolutionized the craft and trade of

  damage, the book advises, and the

  1930s, when the Fairmont Forge tool

  autobody repair. After a revision in

  indirect damage will mostly spring

  26

  AUTOMOTIVE BODY WOR K AN D R UST R E PAI R

  T YP E S OF JOB S

  back into its proper place. This is

  exciting because the area of indirect

  damage usually greatly exceeds the />
  area of directly damaged metal.

  Unlocking the directly damaged

  metal is the key that enables you to

  solve the repair puzzle, usually with

  a great deal less intervention than

  might first seem necessary.

  The Key to Metal Bumping divides

  direct damage into ridges, or outward

  bends and V-channels, which are

  concave, or reverse, ridges. Buckles

  and rolled buckles (added later to the

  damage vocabulary) involve metal

  that has been forced out of place, by

  surrounding metal as damage occurs.

  The book suggests that all direct

  damage can be described in the This damage is somewhat complex, and noodling the sequence of the event(s)

  categories and characteristics of that caused it is of medium difficulty. Still, the time taken to work out a theory

  V-channels and ridges. As with all

  of that sequence is well spent when you have to remove damage like this.

  great theories, author Frank Sargent

  proposes a concept that is relatively

  Here, The Key to Metal Bumping offers

  becomes relatively easy to formulate

  simple but that explains much. He

  a tremendously useful and (for the

  a plausible theory regarding what

  suggests that if you look at what

  time) revolutionary concept of how

  deformed a panel, and in what

  appears to be complex panel damage,

  to look at collision damage. It

  sequence. Please note that such theo-

  you can reduce it to combinations of

  advises examining complex damage,

  ries do not have to be perfect, but

  the items noted above, ridges and and figuring out the order in which

  merely plausible and possible, to pro-

  V-channels. With the addition of

  the metal was deformed; that is, the

  vide the basis for corrective action.

  buckles and rolled buckles, this the-

  sequence of events in the collision

  Once a body practitioner has

  ory becomes comprehensive.

  that deformed it. Where was the

  such a theory of damage in mind,

  Sargent proposes a method of

  panel first struck? Where did the

  The Key to Metal Bumping advises

  working out damage that employs

  striking force go next? What effect

  removing the damage in the reverse

  the least use of force, a novel concept

  did the deforming metal have on

  order of how it was created. In other

  at the time. Taking account of work-

  adjacent metal, and how did that

  words, you correct the last event in

  hardening factors, he advises working

  interact with the deforming force as