body cracks stress

[melliott]

I have an a&c bought 2 months ago with 400 miles on it was flawless. drove 300 miles developed cracks around windshield posts hood corners at rear. around corner of louvers, and around roll bar. I checked clearances don't find anything hitting. I did find no rubber between frame rails and body. I wondered if this could be problem. a new crack is seen everytime I drive it, even babying it in and out of parking lots etc. I want to fix problem before recoating or painting. I also wondered about adding fiberglass stiffening under body in areas where cracks developing to add stiffness. Any help or suggestions appreciated

[427 S/O]

I would go underneath/inside and beef up the openings with layers of fiberglass.

[ratsnst1]

All the places where the body mounts to the frame must have rubber isolaters, or bushings, and your side pipes, should have rubber grommets where they mount to the body as well.

[CHANMADD]

A lot of times stress cracks develop from the mounting of the body.Fibreglass cannot be stretched or bent to fit the frame. The panels and moulded pieces should be fitted with the mounting brackets bolted to the fibreglass, and then when you have it all straight the brackets should be welded to the frame....NO stress on the glass this way!!
John

[PNJSNAK]

Melliot,
I would contact Joe T at A & C. Per the manual there should be some type of body mounting vibration material on the frame rails where it comes in contact with the body.
I have over 14k miles on my 2001 build car. The only stress cracks I have are coming from the corners of the side pipe cutout on the pass side.
I believe they were caused by an object thown into the wheel well from running over it.
No other areas.
Was the body a colored gelcoat or was it a painter body.
If it was a painter body then painted, I believe there has to be some body prep before painting.
If it was a colored gelcoat are the cracks down to the fiberglass? Was the body clearcoated? There are alot of issues to be aware of.
But there should be some type of vibration barrier between the frame and the body.
Like I first said call Joe T at A & C.. Their website is www.acautos.com.
Jim

[cwilson]

Mine has also developed a couple of cracks around the hood corners(the end where the hinges are mounted). I chose the gloss gelcoat option and my cracks appear to be limited to the gelcoat, not the fiberglass itself. Mine has been on the road a couple of years and the cracks appeared right away, but haven't gotten any worse. I was stressed about it for a week or so, but I'm over it know. Your situation sounds a bit worse than mine.

[Rick Parker]

I used a material that was essentially canvas belting like what is used for a Cub Scout Belt. (How's you memory?) I purchsed it at a surplus type store. It was glued with black 3M Weatherstrip adhesive to the areas on the fram that the body was going to touch or rest on. No cracks. [IMG][/IMG]

[eddytheb]

First question have you opened the hood and let it rest on the nose to keep it open. Also do you have good support for the nose of the car and did you force the nose up a little when mounting it. I have a few of Joe's cobras under my belt and I have seen cracks during the build from moving the body around wrong but nothing big at all after the car has been finished.


Stop by and see what we are working on @ www.eddytheb.com

[melliott]

I appreciate all the suggestions. I'm going to check all the mounting points and try to raise body enough to slide rubber in between frame and body then refasten. I'm gonna beef up areas under the body cracks, before repainting.

[jerry w]

post some pics if you can.