Doors & windows in Fiberglass body 1

[kokoboto]

Hi Everybody

I'm pretty new in the field of composites . I intent to construct a race car body out of fiberglass. I've a problem imagining how Doors can be made since I think that when a cutout is made in the body it'll cause large deformation that the door will not fit in . also i think that the door itself will be very elastic if it is cut directly from the body. to make it short , could anybody give me a short explanation of making Doors in fiberglass body . and if there is any resources explaining the process in details i'll be grateful .

 

[MikeHalloran]

In most racing classes where you would be butchering a body by yourself, nobody cares if the door is flimsy, or exists.
You could pre-reinforce the cut lines by laminating some tape on the inside. It will take quite a lot of tape, and weight, to make a difference in how the post-cut door feels.

If you want it to look like you knew what you were doing, you would mold the door separately from the body, and give both some depth around their interface, like flanges deep enough to host weatherstripping, hinges, and latches.

It will take a lot of time and junkyard visits, but you might want to study exactly how the doors interface with the body in current and past fiberglass bodied production cars, and also focus a little on where the cracks appear.




Mike Halloran
Pembroke Pines, FL, USA

 

[kokoboto]

Thanks for your reply Mike.

 

[Tmoose]

The posts by trbomax in this thread is especially detailed and experienced. Durable enough for street, so probably more rugged than you want.

http://www.jalopyjournal.com/forum/threads/scratch-built-fiberglass-body.794367/

 

[bentwings2]

I have a fiber glass streetrod and I've installed a number of funny car bodies on the frames.

The two are very radically different. The race car is just a shell about 1/8 to 1/4 inch thick at the most. There are no doors in funny cars. They do have a roof hatch. These are framed with foam an inch or so thick then glassed over to make a rigid structure. The hatch itself is the same but much thinner as it is not meant to sat upon. I usually put a couple of carbon fiber strips in the roof frame on the foam so it is strong enough for a person to stand on.

The street rod is built more like a conventional car. The body has the Doors and trunk outlined with a substantial wood framework. The hinges are mounted in this. The doors are two pieces laminated together similar to real steel cars. Since mine is a replica it's very close to the original. There is no wood in the doors. The outer skin is about 1/4 inch thick and the inner is 1/8 to 1/4 thick. There are steel backing plates for the hinges. Even with power windows the doors only weigh about fifty pounds if that. The car weighs 2850 with a supercharged small block Chev...about 500 hp.

Molding a body like this is a huge task. The molds are very complex to say the least.

The funnycar bodies are much simpler. They usually come mounted on saw horses on a skid. They aren't really stiff enough to hold their own weight until we get them mounted on the chassis and install the interior aluminum work. It's called " the tin" in the race car world. You must refer to it this way or you will be considered a " newby ". The funny car has a tubing frame work both front and rear made for easy removal of the body. You must refer to this as front or rear " tree" . It's not a tubing frame work in race car conversation. You have to talk the talk..haha

Even building a relatively simple body like this is a monster task. In the old days of the early funny cars the builders would go rent a car and " splash" a female mold off of it. Then it was stiffened and became the plug. Then the first body was molded. From this the modifications were made and another mold from this was made. It was heavily reinforced, cut in various sections for easy break away from the body. These were made easily bolted back together for the final body mold.

That's it very simply.

 

[dcheck]

Your explanation help me to understand the race car .