The door skin is attached...
The door skin is attached to the inner structure by a foldedover flange, and a series of spot-welds to the sub-structure. Removing the skin is not too difficult.
Hammer And Dolly
If the metal on a project is bent, it's amazing what can be fixed by hammer and dolly work. It seems kind of strange that taking a bent piece of metal and banging on it some more will somehow bring it back to its intended shape, but that is exactly what proper hammer and dolly work does. Real experts can truly work miracles; we've seen true masters of the craft rework antique bodies to like-new condition using nothing but the crudest looking hand tools. It takes years of experience to learn near-perfect metal finishing, but simple determination, practice, and patience will build the skill to be good enough for a successful job. The only way to get good at it is by practicing, doing, and trial and error. Some basic techniques need to be learned, and here we can deliver much of what you need to know. The results achieved in metalwork will vary depending upon your skill and experience level, but the end result comes down to how close the metal will be before you "sling the mud" on top.
Once the flange is straightened...
Once the flange is straightened as needed, and an anti-corrosive primer is applied, the new skin is fitted to position and then the flanged ends are folded over the sub-structure.
Some of the proper tools of the bodywork trade are a must-have for metalwork. Unlike your carpenter's framing claw hammer, body hammers are shaped and balanced for working sheetmetal, and it pays to have a good assortment. The basic line-up includes a pointed pick-end hammer, which concentrates blows on small dings. A pick hammer usually has a large flat side and a light overall weight, making this the most useful specialty body hammer for controlled hammer and dolly work. A similar hammer has a flat chiseled end rather than the pick, which is useful for working bodylines. A chiseled-end hammer typically has more weight than a pick hammer, making this hammer a little more forceful. The third most common type is a combination hammer, which is the heaviest. Its square and round heads are for working flats or corners.
Trial fitting should be completed...
Trial fitting should be completed before final welding of the door skin. Panel alignment begins at the doors and works forward with sheetmetal from there. The door skin will retain some wiggle room before it is welded.
A dolly is used on the opposite side of the metal being hammered to focus the force of the hammer blow to the area being worked. Without the aid of a dolly, metal will want to spring over a wide area instead of moving where you want it. There are dollies of all kinds with different shapes, but the one thing they all must have in common is mass. Of the many commercial types available, the heel dolly, which is a relatively thick piece of steel; flat on one side, curved on the other, and shaped like the heel of a shoe, is one of the most useful. Hammer and dolly work comes down to two main techniques: on the dolly, or off.
When hammering on the dolly, the dolly is directly centered behind the metal being struck by the hammer. Essentially, the dolly backs up the hammer blows, and the metal is forced into the shape of the dolly. On-the-dolly work is used for planishing, which is smoothing a distorted section of metal, or when hammering a localized bump from the outside, or a depression if the hammer is worked from the inside. When working off the dolly, the dolly is used just adjacent to the hammer strike, and it applies an opposite force to the hammer blows, while supporting the metal being worked. For example, when working a low area next to a raised ridge, the dolly can be placed in the depression just off the ridge, pushing up the low area, while the hammer work can be directed at bringing down the raised ridge. Off-the-dolly work is useful when ironing out large distortions in a panel's surface.
Trial fitting is an ongoing...
Trial fitting is an ongoing process, with panels being fit-checked several times in the bodywork process. Project g/28 received two new fenders and a steel cowl hood from Classic Industries, while the stock nose, although currently being reproduced, was re-used.
On project g/28, the guys at Johnson's Hot Rod Shop (JHRS) had plenty of opportunity to put their metalworking skills to the test, particularly on the roof panel. Of the remaining original panels on the car, the roof was the roughest part. Alan Johnson tells us: "It almost needed a roof put on it, but it turned out good; the roof was the only bad part on the car. It had a vinyl top on it at one time, and it seems like somebody had been up there sitting on the roof or dancing on it, and messed it up pretty bad." We didn't want to admit to Alan that Hunkins had recklessly and routinely used the roof as a photographic perch.
Another area requiring special metalworking attention was the rear finish panel, which had been hit, resulting in stretched metal. When metal gets stretched, you can knock it up or down with hammers and dollies, but the stretched metal has nowhere to go but out of shape. Here, once the edge of the panel was pulled into position with the aid of a plate temporarily welded to the edge, Johnson's crew employed a heat shrinking technique using a resistance spot welder with a carbon tip rod for localized heat. Heat shrinking with this technique admittedly requires specialized equipment for the multiple applications of localized heat, but there are other ways to get the job done.
An oxyacetylene flame can and will do a nice heat shrink, but be warned that anything but an expert level of skill will more likely distort a panel beyond your belief. That said, the most effective flame shrinking technique is to heat an area about the size of a quarter to a cherry red, and then immediately follow with rapid and light on-the-dolly hammering with a planishing hammer in a circle at the edge of the red zone. Hammer in a tightening circle as the metal cools. Simply heating and cold-quenching a spot of metal with a wet rag, as is often suggested, does very little shrinking.
 Both rear quarters were in...  Both rear quarters were in decent condition, though filler was used to perfect the body surface, and to ensure sharp body lines where parking lot dings existed before. |  Before the filler is applied,...  Before the filler is applied, the protective E-coat finish on the replacement panels is removed from the area, and then the filler is wiped in place. |  Deep sanding scratches in...  Deep sanding scratches in the plastic filler will come back to haunt what seems like a good paint job later, even if they are buried temporarily by a thick layer of primer. Johnson's shop hand-finishes all filler to a smooth 180 grit finish. |
 Sometimes there is little...  Sometimes there is little choice but to repair a given part. The fiberglass lower valance for a 1976 Camaro is not available new, so the cracked original was repaired. |  To make a lasting repair in...  To make a lasting repair in a cracked high-stress corner of the valance, epoxy resin and chopped strand fiberglass mat was used where filler wouldn't stand a chance. |  Once all of the metalwork...  Once all of the metalwork is done, all of the required plastic filler is applied smooth, and the panels are test-fit to perfection, the panels are racked in the booth for primer. |