Thread: C5 gto
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Old 07-15-2017, 08:45 PM
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heinke heinke is offline
MetalShaper of the Month Jan 2018
Join Date: Nov 2009
Location: Livermore, CA
Posts: 396
Post Making GTO trunk lid

I have now moved on to making the trunk lid. On the GTO, the trunk lid isnít very big but itís complicated due to a section that curves around the fuel fill opening. So, hereís the trunk opening that needs to be filled.

The first step was to trim up the opening so the seal would have a consistent spacing around it. Iím skinning the trunk lid in aluminum and will be using a superleggera approach. That is, a frame made of small tube, pieces of aluminum attached to the frame for attaching the skin, and the skin clamped over those. So, I needed to work out how best to attach the hinges to the frame. Hereís my mockup.

I decided to use ĺĒ square thin wall stainless steel tube for the frame. I chose stainless so I wouldnít need to paint it, it would match the polished aluminum interior, and it wouldnít have any galvanic corrosion issues with the aluminum. The first step in making the frame was to make a cardboard template to guide the bending.

I used a Harbor Freight cheapy hydraulic jack pipe bender for the gentle bends and pie cut/weld for the sharp bends. I made the pie cuts by eye and fortunately, they came out good enough. With 3 pie cuts to a corner, the SS is annealed after welding and that makes small adjustment bends for the newly welded corner easy. The overall frame bending is made more complicated in that the frame bends in two dimensions and thereís quite a bit of spring back in the SS tube. So, I spent a bunch of time making small bends this way and that to get the frame to fit the template.

And the real test, does it all open and close smoothly when attached to the hinges. At first it didnít, then I figured out that wedges were needed between the frame and hinge mounts to keep the hinges parallel. With wedges in place, the trunk lid frame opens and closes smoothly.

Thatís it for now.
Joel Heinke
Be original; don't be afraid of being bold!
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