Rear Clip Repair: Part 5

In our last installment repairs to an area of damaged fiberglass on our classic Corvette continued. These repairs focused around the passenger side number four body mount. In this update we pick up where we left off – creating a new fiberglass piece for the body mount area.

The mold that was created in the last update to form the replacement piece worked pretty well, but it yielded a piece a bit larger than what was needed. In fact, it was too big for the steel reinforcing plate to fit over it. To cure this problem, I simply used a die grinder to grind down the piece until it fit nicely with the reinforcing plate.

The photo below shows the reconstructed body mount piece (after grinding) along with the steel reinforcing plate. The reinforcing plate has been bolted to the fiberglass mount as it will be in the final condition. Now that these two pieces fit together properly the assembly can be test fit on the car and, once the size and shape is verified, additional fiberglass matt can be added to finish out the piece.

The reconstructed body mount was then bolted into place using the existing bolt holes in the fiberglass body (these are the bolt holes used to secure the steel reinforcing plate in place). Using the existing bolt holes really helped to align the reconstructed piece. Once bolted in place the distance between the passenger and driver side body mount bolt holes was verified against the same holes on the frame. Thankfully the dimensions matched so I proceeded with finalizing the repair.

So, with the repair piece removed one last time, I trimmed and cleaned the bonding surfaces…

…mixed a batch of bonding adhesive…

…applied the bonding adhesive to the flanges of the repair piece…

…and bolted/bonded the repair piece onto the car. Bonding the piece was necessary both for strength and to create a watertight repair. This bonding compound is very rugged stuff so you need to make sure everything fits right the first time!

After the bonding compound was fully cured the outside of the repair area was taped off…

 

…and several layers of fiberglass matt and resin were applied to complete the repair.

With the bottom portion of the mount reconstructed my focus turned to reconstructing the rear wall around the body mount. I realized early on that this repair was not going to be an exact replica of the factory condition, it just wasn’t practical for me.  However, creating less exact repair did allow me a to easily develop a few simple shapes from fiberglass (mostly angles and flats) and reconstruct the missing area. To me, the most important thing was to develop a strong and durable repair.

So, using the pieces fabricated in my last update, I measured and trimmed each piece to fit. Nothing fancy here, each edge was trimmed with a Dremel and then sanded smooth with a DA sander. In addition all surfaces were lightly sanded to produce a smoother surface and the bonding surfaces were roughened with a 20 grit sanding disk.

 

Here’s an example of the outside corner piece ready for installation on the car.

With each piece prepared the process of fitting them into place started. First the inside corner was bolted into place. You’ll note that I’ve started by bolting the pieces in place rather than bonding them. This approach provided more flexibility for fit-up and will allow me to securely hold the pieces in place while the bonding compound sets up.

 

Next the outside corner was bolted into place (note the frayed edges of the damaged fiberglass were trimmed smooth).

With the two corners in place a flat piece of fiberglass was secured in place to form the rear wall of the body. With the rear wall piece in place the inside corner was trimmed to fit.

 

Now that each piece was in place the joint between the rear wall and inside corner was taped off and several layers of fiberglass matt and resin were applied to make up the joint. Once the fiberglass on the inside of the joint was applied the masking tape was removed and a few more layers were applied to the outside surface.

During this step I also made up the joint between the rear wall and the body mount using fiberglass matt and resin.

Once the rear wall and corners were fabricated the rear deck was lowered into place so the repair pieces could be marked and trimmed to fit. Once the rear deck is bonded into place the attachment between the repair and rear deck will be finalized. In addition the outside corner has been intentionally left bolted in place for now (not bonded). I found there was a fair bit of side-to-side play in the body which was affected by this connection. Since I knew this side-to-side play would affect the final fit of the rear deck I opted to first install the rear deck and then bond the corner together once I was sure everything fit together as it should.

 

Overall I was quite pleased with the way the repair came out. Sure, this wasn’t a purists repair, but the end result is strong and durable and should serve very well for many years to come. With this effort finally completed I can now focus on reassembling the rest of the rear clip – it’s been a long time coming!

 

As for the new additions to the website noted in my last update… well, they’re finally done! I’ve now added two enhancements to this site. The first is the ability to get updates (tweets) on my progress using Twitter. Twitter will be a great way for me to share quick updates with the folks who frequent this site. The second, and biggest feature, is the addition of a new user forum here on the Corvette Restoration Page. I suspect the user forum will take off gradually, but over time I hope it becomes another great resource for everyone here with a host of knowledgeable and passionate members. So, if you have any friends or fellow Corvette lovers, please spread the word and help this new community grow! Both features are free and all are welcome!!!Visit the new Corvette Restoration Forum!