C3 door panels steel or Fiberglass?

[Walter F.]

I was watching one of those car shows on Velocity channel and these guys were restoring a C3. They said the doors were made of steel and prone to rust? My C4 door is fiberglass. Only the mechanical part are steel.

[Mike E.]

Re: C3 door panels steel or Fiberglass?

Fiberglass outer skin. The remainder is steel.

[John C.]

Re: C3 door panels steel or Fiberglass?

Walter

Yes they are correct. On a C3 the outer panel is fiberglass that is bonded to a stamped inner panel of steel.

John

[Rex M.]

Re: C3 door panels steel or Fiberglass?

What the picture is showing is "Two" fiberglass panels with metal brackets riveted to the inner panel. The two fiberglass panels were bonded together with a green two-part adhesive. I know...I worked there, at the General Tire & Rubber Co. in Marion, Indiana.

[Mike E.]

Re: C3 door panels steel or Fiberglass?

Rex,
I am confused by your statement. Did they change the inner structure of the door at some point? I've only played with 68-72 cars, but a magnet always stuck to the inner panel of those doors, and occasionally there were signs of rust. That picture certainly looks like what I am used to with fiberglass outer skin and metal inner panel.

[Terry M.]

Re: C3 door panels steel or Fiberglass?

Rex,
I am confused by your statement. Did they change the inner structure of the door at some point? I've only played with 68-72 cars, but a magnet always stuck to the inner panel of those doors, and occasionally there were signs of rust. That picture certainly looks like what I am used to with fiberglass outer skin and metal inner panel.

Late in 1972 model year we begin to see the door reinforcement bar that became a Federal Requirement for 1973 model year. The edges of this bar are visible looking at the door rear jamb. Whether this necessitated a change in the door frame I do not know, but it wouldn't surprise me that it did.

Rex -- what year(s) did you work at General Tire & Rubber?

[Rex M.]

Re: C3 door panels steel or Fiberglass?

I started working at General Tire & Rubber / Fiberglass Division in 1964. We were molding parts for A.O. Smith when I started and shipping the parts up to Ionia, Michigan for them to assemble. In 1968, General Tire took over the Corvette contract and all jobs were moved to Marion, IN. Almost every part back in 1968, I worked on at some point. In those days I was just a production worker. I know C-4 doors had the two panels but my memory isn't as good as it use to be. I remember the metal impact bars when they started. In about 1970 I was promoted to the Setup man and I had to set up areas with parts (both fiberglass panels and hardware) for bonding & assembly. In the mid 80's I became the General Foreman over the entire Corvette Department. In about 1988 production ceased at Marion and moved to Selbyville, Indiana. I worked for General Tire (Gen Corp) until they went bankrupt in about 1995. Then I went to work for Cambridge Automotive. They went bankrupt too! In about 1996, Meridian Automotive bought them out. I worked off & on for them during C-5 startup, XLR Cadillac startup and finally in 2005 during the C-6 startup. I worked strictly out of Bowling Green from 1992 to 2006, working on any issues with the Fiberglass panels. Most of the time I was in the Paint Department.

[Rex M.]

Re: C3 door panels steel or Fiberglass?

Mike, It's been awhile since I looked at the inner panel on an early C3. I might be thinking of C-4 & C-5 doors. Rex

[John C.]

Re: C3 door panels steel or Fiberglass?

Rex

I think you are correct for all the other generations of Corvettes, but for c3's the inner panel is steel. Here is one with rust on it.

John

[Rex M.]

Re: C3 door panels steel or Fiberglass?

In the early 70's, I worked on all the parts in some way. I sandblasted the door outers plus many other parts, but I never assembled any of the doors. In the 80's(C-4s), I did assemble doors and trained other workers on how it was done and those inner panels were fiberglass.