1. Field of the Invention
The field of this invention relates to repairing holes and rusted areas of automobile and truck body panels.
2. Prior Art
A major problem concerning the typical automobile whose body is fashioned from sheet metal is that certain sections of the sheet metal body tend to rust away. This rusting causes the automobile to become unsightly, which can lead to the owner's disposing of the vehicle long before the mechanical parts wear out.
Coping with this problem has long been a challenge to those wishing to repair the automobile body.
The method of repairing automobile bodies has changed quite materially over a period of years. Some years ago, it was common practice to repair a dented surface or a hole in the body by flattening out the surface as well as possible by hand, and then applying molten lead to the metal surfaces after the paint had been removed. This molten lead adhered to the metal surface and was built up to a thickness sufficient to produce a smooth outer surface. The required area was sanded to provide a smooth continuous surface and the repaired area was then painted to the color of the original body.
This process of "leading" the injured areas, was not only time consuming, but it also required a relatively high degree of skill to accomplish good results. As a result, this method has fallen from general use and has been replaced by alternative methods.
The current methods of repairing rust damage fall into two categories which can be characterized as "temporary" and "semi-permanent."
The temporary method involves applying a pressure sensitive aluminum or stainless steel tape or a fiberglass patch over the damaged area, filling over this patch with a polyester filler, priming the area and painting it. This type of repair, while quick and inexpensive, will generally last only about six (6) months. Such a repair, therefore, provides only a temporary solution to the problem which is generally less than satisfactory.
The semi-permanent method involves fashioning a metal patch to cover the area in question, welding or riveting the patch in place, (or in some severe cases of rust, replacing the entire section with a new section), filling over the area with polyester filler, priming and painting.
This method does not generally provide a fully permanent repair since it does not correct the situation which caused the rust in the first place.
Rusting in an automobile is usually caused by dirt, salt and moisture becoming trapped in a crevice or boxed-in section of the automobile body, so that the body metal is kept constantly damp and susceptible to oxidation. Thus, the rusting process occurs from the backside of the body panels and it is obvious that patches on the surface of a panel do nothing to impede the resuting process and, therefore, such patches are classified as semi-permanent.
This method is less than satisfactory not only because it is semi-permanent, but also because it presents the following problems.
1. A fair amount of skill is required to fashion the metal patch so that it conforms to the original contours of the automobile body. In some instances such as the dog-leg area (the lower area where the rear fender meets the door) the compound curves are so complex that even skilled craftsmen have difficulty in consummating repairs.
2. Skill is also required in attaching the patch or replacement section to the automobile. The repair may be riveted or welded and care must be taken that the original contours are followed. Welding will most times cause metal to distort.
3. In most cases, the patch metal is fastened to the outside of the old metal. Thus a ridge, equal to the thickness of the patch material, is created. Since this ridge must be blended out so that the repair will be pleasing to the eye, the polyester filler must extend a relatively large distance from the repair. This necessitates that the paint be ground off a large area around the repair so that the polyester fill can be graded up to cover the patch and approximate the original contour.
4. Welding or riveting equipment is required.
In many instances, repair of rusted areas is so time consuming, and the cost of skilled craftsmen is so high that the labor cost will result in a price so high that such a repair is impractical.
Clearly, a method of repairing holes and rusted areas of automobile and truck body panels which is permanent, and requires less skilled labor is greatly needed.