In my last post I created a horizontal support bar for the rear fascia, but I still needed a way to physically attach the fascia to the support. I couldn't simply bond it on, because the fascia would've permanently hidden some of the bolts that hold the metal bumper to the chassis, leaving no way to remove either the fascia or the steel bumper in the future. Instead, I decided to bond a steel flange (red) to the fascia that would bolt to a mating flange (yellow) welded to the support tube:
Here you can see the support tube and the underside of the fibreglass fascia resting on it, leaving lots of room inboard for these new metal flanges:
To make this work though, I needed access to the top of the support bar, which was partially hidden by the lower edge of the taillight panel. Since I am planning to make a new mesh taillight panel anyway, the next step became clear... remove the fibreglass taillight panel:
I wanted to keep the fibreglass light panel in case I could use it as a template for constructing the mesh version of the same, so I was careful to cut it out as cleanly as possible:
I set it aside for later, but it would obviously need tweaking since the holes for the taillights weren't very round, and the left holes were lower than the right holes after I had trimmed it square:
That gave me unhindered access to design, weld, and bond the new flanges for the rear fascia:
I used some yellow bristle board to make templates of the upper and lower flanges, which extend inboard from the support tube:
The lower flange nestles on the inside perimeter of the tube so it's flush with the top of the support. I welded it to the support tube and ground the welds flush as well:
Next, I rested the upper flange onto the lower flange, temporarily pinned the two together with a couple Cleco fasteners, and applied a generous amount of 3M Sheet Moulded Compound & Fibreglass Repair Panel adhesive to the upper surface...:
...and then I slid the fascia in place onto the adhesive:
Once the fascia was aligned and clamped in place, I packed more adhesive into the irregular space between it and the upper flange, much like my schematic showed:
When the adhesive cured, I was able to slide the fascia (complete with the upper flange bonded to it) off the chassis at will, leaving the support tube and lower flange behind. All that remained was to make a few final alignment checks, drill through both flanges and bolt them together. These bolts will be hidden but remain accessible behind the new taillight panel:
Stepping back, here’s the rear quarter panel with the removable/adjustable rear fascia:
With that done, I still had to secure the rear door jambs and deck lid jambs to the chassis. The rear quarters conveniently had built-in, hidden, fibreglass return flanges along the door jambs that mated with the Fiero chassis (red):
I simply drilled five pilot holes through the fibreglass and underlying metal, per side, then removed the rear quarters to install threaded inserts in the chassis metal. I used aluminium nutserts that require a 3/8” hole, and a special pair of pliers to swage them into place:
The nutserts accept ¼”x 20 standard coarse threaded bolts once installed. The benefit of these is that they can be installed blind… that is, you only need access to one side.
Once the rear quarters were back in place, I bolted the fibreglass door jamb flanges to the newly installed inserts. Here, you can only see three bolts, the rest had to be installed from behind the panel through the open wheel well:
The last thing to do was install supports for the deck lid jambs:
I measured and cut to length several pieces of 1”x1” steel angle, and welded them fore-and-aft under the deck lid frame. Depending on the final curvature of the deck lid, I may need to remove these and replace them with suitably arched supports. Time will tell:
These modifications should be enough to support the rear quarters and secure them from shifting around while doing other body work later on. I could have secured the upper quarters from underneath as well, but I decided the flying buttresses connected between the quarters and the roof would provide more than adequate support.