Automotive Bodywork and Rust Repair

by Matt Joseph

  too deeply in any area. Lead can be

  out flexible backing, were used to

  nose body file, and then switched to

  added to areas where it has been filed

  sand some fine details into some

  a flexible file holder and file to work

  too deeply, but this is a tricky fix and

  areas of the lead and steel surfaces.

  on the flatter surfaces. Several differ-

  care should be taken to avoid having

  Final sanding with 120-grit abrasive

  ent shaping tools were used.

  to resort to it.

  paper completed the surfacing phase

  During the filing process, the

  After filing was completed, the

  of the job.

  panel surface was constantly moni-

  surface was sanded with 80-grit abra-

  The entire repair area was again

  tored, visually and by feel, to make

  sive paper mounted on sanding

  neutralized (killed) with metal con-

  sure that it was smooth and continu-

  boards. These boards place some-

  ditioner, completing the repair.

  A variety of body files

  1

  was used to achieve

  final, correct surface contours.

  This bull-nose file has a

  convex lateral format, and was

  perfect for removing material

  quickly and accurately in the

  concave area of this fender.

  This flexible file holder

  2

  and file can be shaped

  to match desired surface

  contours. Most of the lead

  shaping and leveling was

  done with this setup. A good,

  sharp body file removes both

  lead filler and body metal,

  allowing the blending of both

  metals into a continuous

  surface.

  130

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

  M I NOR R UST R E PAI R TO A F E N DE R E D G E

  Other files, like this round

  3

  bastard file, are useful for

  getting into tight areas, where flat

  files might tend to cut destructive

  channels and ridges into the lead

  filler and body metal. Filing requires

  great concentration, and involves

  both feel and visual inspection as it

  progresses.

  As the filled surface was filed,

  4

  it was important to constantly

  feel surfaces and check for any

  depressions or raised spots. Proper

  filing technique employs files to

  blend raised spots into desired

  contours, and to avoid creating or

  lowering depressed areas.

  Filing was followed by board

  5

  sanding. This board sander

  has a somewhat soft rubber backing

  under the abrasive paper. That helps

  to achieve continuous surfaces that

  have no unauthorized high or low

  spots or areas.

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

  131

  CHAPTE R 12

  Final sanding can be a finicky

  6

  operation. Here, a paint stick

  was used to back abrasive paper. The

  surface warping of the stick is used

  to create a mildly concave or convex

  sanding tool, as required to contour

  and level the surface.

  The final, repaired surface is shown

  here. It is not perfect. Very minor

  applications of spot putty will be

  needed in a few places to fill small

  depressions in the lead.

  132

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

  C H A P T E R 1 3

  REPAIRING COLLISION DAMAGE

  IN A DECKLID

  This job is to repair the lower area

  of the rear decklid from a 1937

  Chevrolet sedan. The original panel

  was punched in by impact from

  another vehicle hitting it from the rear.

  Most of the damage was to the right

  side of the decklid, but some damage

  also occurred to the center and on the

  near left side of the lower panel.

  The damage amounts to a series

  of related and unrelated deforma-

  tions in this decklid’s skin. This com-

  bination results because most of the

  damage was indirect; it was forced

  into the metal by direct impact

  against the heavy trim pieces

  attached to the panel. The impact

  from the second vehicle was primar-

  ily against the trim, which in turn

  pushed the decklid skin in from sev-

  eral points of the trim’s attachment

  This is the starting point for the metal straightening, finishing, and filling job. It

  to the panel. In some areas, one dent

  amounts to correcting several related and unrelated dents in the decklid of a

  created or modified another. Some

  1937 Chevrolet sedan. My good friend, Herb Statz, is shown working in many

  areas of the damage are quite unre-

  of these photos.

  lated to each other.

  There was one small but particu-

  metal that will begin to return to its

  the damage. Damage is revealed by

  larly significant area of direct-impact

  proper shape and position when the

  close inspection, and that inspection

  damage. This small area was hit

  direct damage is removed.

  is aided by removing anything that

  directly by the second vehicle, and

  After removing the trunk lid’s

  interferes with viewing and feeling

  has severe direct damage that is lock-

  trim and body gaskets, we obtained a

  the damage as minutely and directly

  ing in a large area of undeformed

  better idea of the type and extent of

  as possible.

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

  133

  CHAPTE R 13

  This photo illustrates a subtle but important point: The

  innocuous-looking scrape between the two white arrows

  As hopeless as it may look, always remove body gaskets

  was the only area of direct impact that deformed this

  and trim carefully, as if you will have to reuse them, because

  panel. The other damage was done by impact against trim,

  it may just come to that. If you don’t have new items in-hand

  which also deformed the panel. Understanding this is key

  before you remove the old ones, keep the old ones for

  to repairing the panel.

  patterns, just in case.

  This is important because the

  This job divides into three major

  deformed the trunk panel into a sec-

  point of direct impact damage is

  areas of damage, and a few smaller

  ond area of damage that extended up

  locking in a tremendous area of

  ones. First the trunk lock and associ-

  to and slightly beyond the top mount-

  metal that can be released when it

  ated trim pushed in the panel metal

  ing point for the license plate bracket.

  is relieved. Then the locked-in

  under them when they were hit.

  A third, separate
, area of major

  metal in the panel will be on the

  That damage was evident on both

  damage was evident on the lower

  way to assuming a shape that is

  sides of where the latching mecha-

  right side of the trunk. This was

  pretty close to its original format. A

  nism was mounted.

  caused by direct impact in the center

  little work on the direct damage, on

  Second, the damage traveled

  of the dent. It produced a deep and

  the ridges surrounding it, and on

  upward, pushing in the license plate

  severe rolled buckle, upward from

  the indirect damage will produce

  bracket, which may also have sus-

  the point of impact. A less serious

  dramatic results.

  tained some direct impact. That

  rolled buckle extends to the right of

  134

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

  R E PAI R I NG C OLLI S ION DAMAG E I N A DECK LI D

  This view and lighting shows the

  nature of the damage particularly

  well. Three distinct damage areas are

  easily visible. The direct damage

  point is obvious, as are the deform-

  ations caused by the trim and bracket

  items. It is easy to see where and why

  the damage stopped moving through

  this panel.

  fectly fits in and aligns with its jamb.

  Its diagonal measurements remain

  exactly symmetrical.

  If there was no substructure

  behind the decklid skin, it would be

  relatively simple to rough the dam-

  age out of it. Some hammer-off-dolly

  and hammer-on-dolly work would

  successfully remove the buckles and

  These two views of the damage illustrate how different things can look when

  ridges, and relieve the relatively small

  seen in different light, and from different angles. Only by examining damage

  areas of damage that are locking most

  from several viewpoints, and manipulating the light on it, will you fully

  of the out-of-place sheetmetal into its

  understand it.

  presently deformed state.

  Now the bad news: The decklid’s

  the direct impact point on the panel.

  As is usually the case with colli-

  substructure prevents direct access to

  Metal was also deformed and dis-

  sion damage, there is good news and

  the areas where almost all of the cor-

  placed downward from the point of

  bad news. The good news is that the

  rective work needs to be done. The

  impact. The damage in this dent was

  supporting structure of this decklid

  exception to this dismal situation is

  stopped by the crown of the metal at

  held its shape. There is no overall

  that there is good access to the back

  its top, and by edge substructure at

  dimensional deformation in this

  of the center dent’s upper area,

  its bottom and to its right.

  panel, in the sense that it still per-

  behind the license plate bracket.

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

  135

  CHAPTE R 13

  The other approach—the one

  that we used—is to leave the sub-

  structure in place, and to work

  around it with pry tools and other

  specialized tools and techniques.

  This is a much more cumbersome

  and time consuming way of doing

  this job, but it has two distinct

  advantages. First, it maintains the

  shape and alignment of the trunk

  lid. If substructure members were

  removed to straighten the panel

  surface, it would be almost impossi-

  ble to maintain the shape of the

  decklid, and a difficult refitting

  process would be required. The fact

  that this decklid is still in near-per-

  fect alignment with its jamb is an

  advantage that should not be

  ignored.

  The other major problem with

  removing and replacing substruc-

  tural members for access is that it

  would require considerable time to

  re-weld and refinish them. This

  would probably offset and possibly

  cancel out any time saved. Finally,

  the substructure around the lower

  and right edges of the panel could

  not be removed without severely

  disturbing and deforming the panel

  The substructure under this decklid panel severely limits access to the panel’s

  in those areas.

  back side, making it much more difficult to work on. Actually, there is great

  For all of these reasons, we

  rear access to many areas that do not need attention, and very poor access to

  decided to work around the sub-

  most that do.

  structure, rather than to remove it.

  Please note: The decision to work

  The Approach

  to its original format, the removed

  around the decklid’s substructure

  substructure would then be welded

  does

  not

  change

  the

  basic

  There are two possible approaches

  back into place. This way of doing

  approaches to removing collision

  to repairing this damage. One would

  this job would probably be faster

  damage, outlined in earlier chap-

  be to cut away enough of the deck-

  than any other way of accomplish-

  ters. The theories and sequences of

  lid’s substructure to gain access to

  ing it, such as the one that we

  damage removal remain the same

  the critical areas on the back of the

  decided to use. Also, it would yield a

  because the elements of cause and

  panel, and then approach the job

  panel surface that would require lit-

  effect in working damage out of the

  with conventional hammer-on-dolly

  tle metal finishing and filling. The

  sheetmetal do not change. What

  and hammer-off-dolly work in those

  panel surface could be brought

  does change is some of the tools

  areas. With this approach, after the

  pretty close to its original format eas-

  and techniques used to accomplish

  metal in the panel had been returned

  ily and quickly.

  the job.

  136

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

  R E PAI R I NG C OLLI S ION DAMAG E I N A DECK LI D

  The Early Steps

  Coming up with an effective

  strategy for dealing with collision

  damage requires seeing the damaged

  area clearly. In this case, applying

  some paint stripper to the decklid,

  and removing the loose rust with

  coarse steel wool, revealed previously

  invisible detail in the lower-right

  part of the panel.

  It would be difficult to overstate

  the importance of using all of your

  relevant senses to understand impact

  damage. We’l
l pass on smelling and

  tasting it, but feeling damage and

  looking at it from many different

  angles are necessary to gain enough

  information about it to formulate a

  good plan to repair it.

  Analysis of the damage in the

  right dent suggested that it was

  After chemically removing the paint and scuffing the loose rust with

  caused by direct impact. A key to

  1

  coarse steel wool, in the lower-left part of the panel, its surface looked

  unlocking the damage in the entire

  very different. It was then much harder to spot the area of direct impact.

  dented area is to gently work out the

  Feeling damage with your

  2

  fingers often divulges

  information beyond what your eyes

  can see. Tactile data can be as

  While the outside of this panel revealed what needed to be done to

  3

  important as visual data in planning

  repair it, its underside showed how difficult it would be to gain access to

  approaches to removing collision

  several key areas. It is always best to understand the extent of such problems

  damage from autobody metal.

  before you begin to work.

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

  137

  CHAPTE R 13

  crease that is evident at the impact

  point. Following this, apply gentle

  pressure against the dented area,

  while lightly hammering on the

  ridges that surround it. This will be

  difficult at the right and bottom

  edges of the panel because there is

  supporting structure behind the

  metal in those areas.

  The favorable factor in this dent

  is that most of the metal in the large

  damaged area is not badly deformed.

  It will spring back into its approxi-

  mately original and correct positions,

  We started with a plan. First, we would correct the direct damage. Then,

  4

  we would push and hammer out the long, vertical V-channel above it,

  while hammering down its rim. Similar strategies were planned for the rolled

  buckles on the right, below, and to the left of the direct damage.

  Usually, feeling the back of a

  6

  panel reveals where things are.

  However, in this case, substructure

  interfered with feeling the knot of direct

  After the work was completed, most of the displaced metal in this dent

  damage under it. To ensure accuracy in

  5

  was released. Then, with a little underside persuasion with mallets, the

  prying it out, we used a large set of