What is the metal inside of the rocker panel?
 

The body and frame guy was talking to the guy doing the 4 link suspension on my project car. He had fabricated new outside and inside rocker panels for both sides of the car. When he cut the old out to put the new ones in, he found a third metal panel inside the rocker panels. It runs the length of the car inside the inner and outer rocker panels. He wanted a notch or hole so that he could weld all three parts together at one time. He tried to notch it with a plasma cutter and could not cut it. He tried to drill holes and trashed 4 drill bits. He ended up welding the new parts on one at a time. I asked him if the metal was still shinny. He said that it was. I am thinking some kind of high quality stainless or a very high chrome alloy. Does anyone know what metal it is? The car is a 62 convertible. My guess is that the plate makes the rocker panels act like a boxed frame around the bottom of the car.

It acts like a girder reinforcement inside the rocker panels.


Since the 62 and 63s Convertibles (Tempest+Lemans) do not have "wash n dry" rockers as used on all 64 and up GM A body cars. I am sure GM used some kind of special metal or treatment to normal steel but thicker metal and perhaps it was galvanized.

Radman, I think your guy needs new tools. I cut up a nice 63' convert with only a sawzall. Only thing special about the rockers is the galvanized coating.