by Chris Petris
(Taken from How to Restore Your Corvette 1963-1967 Engines by Chris Petris)
Since its release in 1953, the Corvette’s body has been constructed of fiberglass, and as such, the replacement and repair techniques are far different than traditional stamped sheet-metal panels. Cracked, chipped, and punctured panels can be patched and repaired, but if the damage is extensive, the panel must be removed and replaced.
Removing any fiberglass panel is not for the weak-hearted.
You must break loose the bonding adhesive from the panels. Hearing the crunch of fiberglass as you break each seam loose can be unnerving. To make matters more challenging, you must remove the piece to be replaced without breaking the bonding flange. Professionals use a variety of specially shaped scrapers and knives to access the bonding areas. The idea is to avoid damaging the fiberglass panels’ mounting flange.
Once the bond breaking tool has been placed between the flange and panel, slowly tap it around the piece being removed. Make sure you keep the tool centered in the bonding adhesive. Do not dig into the fiberglass-mounting flange because they are tough to restore back to original strength if broken.
Once the complete panel to be replaced is out of the way, flange clean-up begins. The idea is to remove just the old bonding adhesive, then roughen the flange for the new adhesive. Remember the fiberglass goes away quickly when using a high-speed grinder.
Once all the flanges have been cleaned up, it is time to fit the panel. Most fiberglass manufacturers leave material at each end of the panel to allow proper fitting. They usually have notes on the panel that state “FIT PRIOR TO PAINTING.” That absolutely means you own the panel if it has paint on it.
Since I am installing a major fiberglass assembly, I need to consider what other body panels are affected. I should check the door gaps to door frame before installing the front end. My resto expert, Seth, likes to center the doors on the hinges first. Then he checks the fit of the door at the front where the front end meets the vertical door seam. The goal is to avoid doing any major reconstruction of the door gap at the front. Seth explained that, if necessary, he could build up the rear of the fender for a nice, tight, even door gap.
Always think about what other panels come into play before bonding any panels into place.
For the ’63, I need to check the fit before bonding: I had a really good looking 1966 convertible come into the shop in baskets, boxes, dollies, you name it. The bodywork was completed and the paint looked very nice. All I had to do was put it together. After being on the receiving end of so many of these “all you have to do is put it together” projects, you become highly skeptical of these jobs because they are never that simple.
The first tool I pulled out of the box was a tape measure. With the customer standing alongside me, I did a diagonal measurement of the frame. Sure enough, it was tweaked. The first order of business was having the frame straightened. But that was just the first of one problem after another.
Once the frame had been assembled, it was time for the body installation. At that time, I found some serious problems. Remember, I said the body had really nice paint. But when I began assembling the exterior, things went horribly wrong: None of the taillights fit properly in the rear surround. They weren’t off just a little; the rear surround needed extensive reconstructive surgery to get the lights to fit.
What I am trying to stress here is that you make sure everything fits before any primer is sprayed and absolutely before any top coats are applied. That project cost plenty extra to fix everything so that the car looked presentable.
The doors should be fit prior to hanging the front end on the cowl. The front end can be held in place with screws as each area is fitted. Once you feel that the front has been fitted properly, go back and check the door gaps. The old adage “measure twice, cut once” applies here. Fit everything carefully, then check everything again for fit. Once you glue the panel in place, you risk damaging it if you have to remove it for placement changes.
The hand-laid one-piece front end is sitting upright and ready for installation. The tan vertical bonding strip is in place right above the wheel opening. The lap joint is where the front and rear strips come together.
You should have everything ready and waiting for the adhesive installation process. The fasteners holding the front end in place should be removed, and the front end set aside. Have all the fasteners in an easy-to-access location with the proper installation tools. Now, the bonding adhesive is mixed for application on the flanges.
Be sure to read and understand the bonding adhesive manufacturer’s recommendations, especially on setup time. You have to apply the adhesive, then put the front end in place with the fasteners within a set time, dependent upon ambient temperature. Once the front end is set in place, your fasteners should be installed to align the assembly correctly.
Wipe off any excess bonding adhesive. General Motors did not do that, of course; they assembled plenty of cars daily, so the assembly line workers wasted very little time cleaning up. NCRS cars should not have the excess bonding adhesive wiped clean for authenticity. At this stage, it is a matter of waiting until the adhesive sets up, which often means letting things sit overnight.
Once all the major fiberglass issues have been taken care of, minor repairs should be handled. The details make a big impact on how well the finished project looks. During an earlier inspection, I noticed a few additional holes in the firewall from accessories that were added over the years. Screw holes in the fiberglass strip out easily and require repair to avoid having to use incorrect hardware. Look back at your notes from the disassembly phase and make the repairs before the paint is in place.
Green masking tape is used to check the front end’s bodyline in relation to the body. You want to make sure the front end is not running downward or upward. This is the last chance before gluing the panel in place to make sure the front end is positioned correctly.
Final fit check is in order now. This is your last chance to make any adjustments or changes to component fit. Check the fit of each emblem in its respective position. Do they sit flat against the panel? Make sure the grille, rear taillights, etc., all fit properly. Check door gaps and hood fit. One final once-over can save you plenty of aggravation when it comes time to assemble.
Now, you’re at an exciting point in the restoration when it’s time to install all the exterior trim items, and you are able to see just how great the finished product looks. Or it can be a game changer with a “for sale” sign and multiple boxes of your pride and joy on the floor.