Bird Cage fitting?

[Three Peaks]

Scratch builders and owners of Shelby fiberglass Cobras-

I've pretty much got my front and rear bird cage supports fitted and ready to weld in place- now comes the part I've been putting off until I had the courage to start on it. I have to get the door area and dash supports bent, fitted and installed.

I've looked at the Kirkham pictures but they really aren't helping me out much so I need to ask a couple really basic questions here (for now, I'll have many more later ). This is one thing I can't seem to figure out by looking at a completed car, unless somebody will let me put their car up on a lift!

When fitting the framework around the doors, do they fit into the channel under the door, outside the channel under the door sill, or just under the channel and just touching the body skin for support?

The Cobra restorers drawings show the birdcage but not how it fits to the body and I don't trust the dimensions on the drawings at this point.

Also, when doing the hood, trunk, and door hoops, are you using 1/2" OD pipe for these hoops? How do you form an inner door skin, or do you simply fair the hoop in with epoxy when finishing the inside of the piece? Does anyone make an inner door and/or hood liner that could be bonded to these door skins to give a more finished appearance and mount the hinge points to?

Thanks, Bob

[Dominik]

hi Bob,

we made the doors tubes from 3/4" tubing, which will be bonded onto the single skin.

on those tubes one has to weld the door hinge and latch support.

for dimensions, just place the tubing with half a finger's gap in the relevant opening.

the pic doesn't show that the upper tube will slide all the way in to be hidden by the upper part of the door.

Dom

[Dominik]

trunk

the drawings for the hinges as well as brackets to the doors/hood/trunk are not part of the CR drawings.

also, I was told the CR drawings are for aluminium bodies and not for fibre.
the main difference is the rear scuttle where the door striker plates are fitted.

this hoop is a pain to bend, even if you have sample.
try to make it work according to the CR drawings and let me know how it came out.

dom

[Three Peaks]

Dom,
Thanks, that explains a lot about how the tubes fit, since the originals were aluminum bodies.
I was able to get the tubing around the door sills bent yesterday as well as the tubing for the dash support. Still have to make the shorter pieces to tie both of them into the frame front and back, respectively. I'll need to borrow a buddie's pipe bender to make the shorter bends for those though. So far, my electrical benders have been working great, but slow.

I've had to make some adjustments on the pieces supporting the front of the cockpit at the dash and the rear. Roger made this Carbon Fiber body with a rolled edge front and back of the cockpit that is a complete rolled fillet just like the pipe should fit into it. It requires moving the hoops a bit to fit, but should give a beautiful finished edge when sanded out and finished.

How are you planning on finishing over your door, hood, and trunk hoops? Some guys I've seen use an epoxy coating and fair them into the piece- which is what I think I'll probably end up doing with this build.

The devil's in the details, isn't it? - Bob

[Specialk]

The Shelby fiberglass cars do not use the birdcage tubing that surrounds the cockpit and doors. The engineer felt it was not necessary because the fiberglass is rigid enough to support itself. On the aluminum cars all that tubing is needed to wrap the body over, and it needs to be accurately placed with all of it smoothly transitioning from piece to piece. Since the 'glass body is already molded into shape, the only reason I can see for installing any of it is to mount the door striker. Shelby gets around that by forming a one piece scuttle hoop in the rear:




All the superstructure tubing is 3/4". The early Shelby cars had the aluminum flashing riveted to the door, hood, and trunk frames just like an aluminum car. Then it was laminated to the skin. Now the use Lords adhesive to simply bond the tubing to the skin.

[mickmate]

Those compound curves are fun aren't they? The back of the cockpit and the door and dash stuff that makes 3 curves at once! Do you use the conduit bender in the vice? I did and make and erase a lot of sharpie marks

[Three Peaks]

Yeah, those compound bends are a real riot! Trying to fix a couple I've overbent, the pipe slips in the bender and I've been beating the heck out of myself a few times. I usually use a "hickey" and stand the handle on the ground with the head up in the air and bend by eye- as I do a lot of that for a living anyway.

Most of the pieces are pretty close now, but I am going over to a guy's place tomorrow to borrow his bender for the shorter bends I need to make from the door hinge supports to the dash support and the area behind the door sill. Then just a little tack welding and I can pull the body off and finish welding up the birdcage. I'll be glad when that part is done!

Got to look real close at a Kirkham this weekend at the Portland Historic Races and I was able to see how the hood, door, and trunk hoops are done. With the right bender it should be a piece of cake. (famous last words, huh?)