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So does that refer to SMC introduction in 71 or to the use of Gennite in 70 and 71.
A couple of quotes from my searching.......
“The first SMC panel was used in `71 and just happens to be the rear quarter fender. All of the earlier versions of corvette fiberglass that fender came in, polyester glass(1968-69), Gennite 70-71, and SMC (71-73) were all press molded, but used different base materials.”
"The `71 had a mixture of panels ranging from the old polyester to Gennite and the first SMC panel which was first used on the rear fenders sometime during the year."
Looks like it was a fast and continual development in the early 70’s.
Gennite would appear to have been a transitional product between the older style press moulded fibreglass and SMC.
Now I just need to decide if to redo the rear quarter repair.
"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."
Hi Craig,
?
The paragraph I posted is from the Oct/Nov 1970 issue of the Corvette News.
It was the issue that introduced the 71 model year cars.
Regards,
Alan
Been reading through more NCRS stuff but its not fully clear in my mind if Gennite is closer to Polyester or SMC
A comment re bonding
"panels which could have been made of Polyester, Genite or SMC coumpounds. Because of this, recomending an adhesive is difficult except to say that epoxy should work OK at least for the bonding part on all of them. However, you would not want to use polyester adhesive on an SMC type panel."
That would infer Genite could be bonded with the Polyester glue.
Been reading through more NCRS stuff but its not fully clear in my mind if Gennite is closer to Polyester or SMC
A comment re bonding
"panels which could have been made of Polyester, Genite or SMC coumpounds. Because of this, recomending an adhesive is difficult except to say that epoxy should work OK at least for the bonding part on all of them. However, you would not want to use polyester adhesive on an SMC type panel."
That would infer Genite could be bonded with the Polyester glue.
Craig, you have fallen into that pit of NCRS correctness. I started out that way wanting to emulate like a Alan car and I drove myself crazy trying. A major reason for me being 5 years into my restore. The first half was nothing but being NCRS correct with everything. It finally drove me to the point of giving up that idea. It is addictive and there are some that feel it's the only way. When I hear the you are maybe redoing stuff I think back to my project when I did the same. Good luck as I continue to watch.
The early design SMC panels ...ro what is called 'genite'...is just that. The process of making these panels changed...and thus....it is wise to treat it as if it was a current design SMC. So...I would not sue polyester resin to repai cracks in this pajnhel or lamiante on. BUT..adn this is wher it gets confusing. i WOULD sue Vette Panela Ahdesibv to fill over and reapir blemishes int teh SMC or 'genite' panel.
The reason I say this is due to the numerous Corvettes I have worked on that are in this transition era of body material GM used. And I have seen polyester resin sticks like glue and I have also seen polyester resin filet right off the panel.
So..I err on the side of caution and use the epoxy resin and have never had an issue with adhesion.
And to throw another 'stick into the works'....and to confirm what was previous mentioned...The 1973 Lingentfelter drag car I am working on has SMC or if you want to call it genite exterior panels but the floor pans, fire wall and rear tub area are all polyester press molded.
What it looks like is someone backed the Vette into a half open garage door and cracked both sides of the halo in the same spot. Very strange as damage is in same spot on each side and is mostly just the edge.
It may be hard to see but the repair is 3 seperate applications of glass. First a layer from under the Halo then when it is firming up a layer to the edge of the halo and finally on the top.
I had ground out the broken areas first.
When its good and hard I will start to shape it into the proper curves.
Hi Craig,
NICE!
You're right... an unusual damage at an odd location!?!
One comment.
I think it's a good idea to slightly 'ease' the edges on the valance where it sits against the rear tail light panel and the lower quarter panel joint.
This seems to give a more pleasant appearance when the paint is finished and the panel installed.
(Yes, I know the bumpers hide some of those joints but it's still nice to have them well done.)
Regards,
Alan
Hi Craig,
NICE!
You're right... an unusual damage at an odd location!?!
One comment.
I think it's a good idea to slightly 'ease' the edges on the valance where it sits against the rear tail light panel and the lower quarter panel joint.
This seems to give a more pleasant appearance when the paint is finished and the panel installed.
(Yes, I know the bumpers hide some of those joints but it's still nice to have them well done.)
Regards,
Alan
Thanks Alan
By ease the edges do you mean take off the 90 degree edges or increase the gaps.
Hi Craig,
I meant take off the 90 degree edge.
I use a piece of fine sand paper and slide it along the edge to slightly round it off.
Not enough to change the apparent gap....just not a sharp/cut edge on the fiberglass.
You DO do nice work!
Regards,
Alan
YES...I apply VPA on my laminations when completed if they are important enough to do so. Seeing how you have the VPA now....I would use it. Because if you have both. The VPA and the Fiber Tech...you can clearly see they are quite different. But use what you are comfortable with using.
First ground down the excess epoxy and glass with a Dremel and 80 grit wheel. Followed by a rasp to get basic shape then 40 and 80 on as long a block as possible.
03-14-2018, 07:28 AM
