'72: Fiberglass Type Identification

[Chuck S.]

Re: '72: Fiberglass Type Identification

Patricia, I would be happy to look at them, but I am questioning if I even know what's what anymore.

According to Eckler's blurb, they do not recommend their gelcoat be used on 73-82 because of SMC panels, and 73 is earlier than I thought for SMC. You said you thought they were completely SMC by the mid seventies. Gennite must have only made it to a few panels before they starting changing again to SMC.

Wayne's suggestion of going with a hybrid bonding system on the rear fender bond will allow you to use polyester adhesive on the Sermersheim panel, but I'm not sure it really gains you anything if the rest of the body panels are SMC. The polyester adhesive is probably easier to work with, but you still have a problem using the polyester gelcoat on the other panels.

[Wayne W.]

Re: '72: Fiberglass Type Identification

No problem, send the pictures. This is the way the panels evolved. They were polyester until late 69. In late 69 Genite panels started to be worked in. The first was used on 69 doors. The genite panels are generally medium gray in color and show much less surface fibers. The first SMC panel was installed on 71 rear quarters and worked in for other parts until the whole car was SMC by 74. These early SMC panels tended to be lighter gray in color and had a little more marbling, but they are dificult to tell from the Genite. Later SMC panels and over the counter replacements tend to be very slick on the surface and show a lot of marbling. GM used the dark bonding adhesive into 69, but changed sometime later to the pinkish color. I guess this was an attempt to get a better bond on the later panels.

[Patricia Brown]

Re: '72: Fiberglass Type Identification

Thank you guys for looking at them. I'll be very curious what you think. In none of these shots is the tail light panel in place. It was VERY marbly, especially noticable when wet down with lacquer thinner. It was very slippery, thinner, dense and plastic-like, much more than any of the other panels. I think it was a later replacement, as the rear end had a lot of damage. Its appearance matches what you say, Wayne, that the later SMC panels were very slick and very marbled.

Patricia