Long considered undesirable relics of the disco era, 1978-1981 Camaros are quickly gaining popularity among car builders. Several factors contribute to this phenomenon, including skyrocketing prices on everything from the muscle-car era. There are some inherent problems with these cars, though. They were plagued with urethane front and rear fasciae that generally didn't weather the test of time well and are difficult to restore.
Derek Putnam of National Parts Depot (NPD) shared with us that the company has been offering aftermarket fiberglass front and rear fasciae since early 2010. "New covers were added to the catalogs due to the poor fit and waviness that most original-style urethane covers would commonly show," he explained. "The new Flex Glass fiberglass technology offers lighter weight and better resistance to corrosion and temperature, all while retaining a better-than-original shape and fit."
Prices reflect the technology that goes into production on these parts. The front is listed at $690,and the rear cover is $421. For ZedSled, the goal was to achieve a great fit with less installation time, but by far the biggest reason we used NPD's Flex Glass bumper is the ability to easily customize it. With the addition of twin turbos, we needed a lot more air coming into the front due to the air-to-air chargecooler, and we simply had to open up space for ambient and motion-induced airflow.
There is no mystery when working with fiberglass; this technology has been around for decades, and it's easy. You can buy a fiberglass repair kit at nearly any auto-parts store or home center and use it to easily customize your parts to suit your needs. The side benefit is obviously a superior fit right out of the box and a shape that's not going to deteriorate over time, which is worth paying a little more coin for!
This is a typical "bird bath" on a 19781981 Camaro bumper, and it's the most common complaint from F-body guys who restore these cars. The bumper reinforcement simply doesn't support the shape of the urethane cover, and this waviness is the result.
A fastener that holds the header to the fender is responsible for these heartbreaking cracks. As the car flexes and the parts settle, the paint and coating materials crack because they can't tolerate how far these parts can move.
Here is more evidence of the weak substrate. All it took was a few heat cycles for these cracks to show up around the lower air inlet, and they are only going to get worse, no matter how much we patch and paint.
Fast-forward to our turbo system mockup: the Sled is going to need a lot more air moving into the nose, and we've modified everything from the radiator location to the face bar of the bumper to allow for airflow to the intercooler.
Looking at ZedSled's original fascia shows the lower opening that was purely aesthetic and nonfunctional. You can also see the sad and deteriorated condition of the OE cover, sags and all.
Our plan is to integrate two upper grilles into the nose, so to make a mockup, we sliced up the old urethane cover to design the new air path. We sourced the upper grilles from eBay, purchasing both of them for less than the cost of the nonfunctional lower grille, because they're difficult to find.
The Flex Glass bumper from National Parts Depot holds its shape even while mounted loosely on the fender stand, and we're impressed with its overall quality, especially the gelcoat.
After transferring the mock-up design to the new Flex Glass bumper, we used an air saw to cut the new shape of the lower air inlet.
Using locking pliers and sheetmetal screws, we dialed in the placement of the new lower grille as a guide to use to rebuild the structure around it.
We used plastic tape and our "calibrated eyeball" to establish our centerline. You can see how the changes to the lower inlet retains the look of the nose, but increases room for air yet maintains a retro-styled look.
I always precut the fiberglass matting before mixing resin. This creates less mess and makes it easier to manipulate smaller pieces into shape. The matting and resin were purchased from a local automotive retail store for less than $20.
We screwed some aluminum TIG wire into place for support and laid the saturated matting over the shape. The resin takes about 20 minutes to harden, and the shape can then be built upon until the final shape is formed. By the way, it takes 18 drops of hardener for every 1 ounce of fiberglass resin—pretty simple!
After four sessions of laying the glass matte into place, we achieved this roughed-in shape. Test-fitting the bumper cover onto the fenders shows the massive air path we created for the air-to-air intercooler. With the shape established, we can now proceed with simple bodywork techniques to shape the fiberglass.
For final fitment, we'll insert the original header panel into the NPD cover. This will allow us to bolt the new fascia in place and test how it fits to the fenders and hood.
The assembly fell into place easily on the car, giving us a nice, even panel fit all the way down the fender and around the headlights.
One of the brilliant aspects of this bumper-cover design is the mold lines are integrated into the edges and not into the panel's visible contours. This creates "casting flash" on the edges, which is shown here on the tape. Edge trimming will be required, but this is better than having to reshape the panel.
Another benefit of the extra glass on the edges is that it enables us to tune in the panel gaps. A rotary grinder with an 80-grit disc lets us slowly refine the shape to the hood so we can create a better-than-original fit.
Masking tape provides a great straight edge for reference. The black marks show us how much material we need to shave down.
Body-shop experience is not necessary for this job, but it helps. A 12-inch sanding block and 80-grit sandpaper make it easy to shape the hood gap relative to the bumper.
We're using Upol Dolphin Filler to blend the shape of the bumper to the fenders. This isn't necessary for restoration project, but we're going for a custom look with black paint, and a skim coat of filler helps contour the final shape to perfection.
We scuffed the target areas with 80-grit to promote filler adhesion, then applied a very thin coat of Dolphin Filler to a few of the transition areas and around the custom lower opening.
We block-sanded the filler with 80-grit paper, followed by 180-grit, which gave us a surface that's ready for primer.
With fiberglass, it's best to cover any fabrication or repairs with gelcoat. This will help eliminate shrinking, "mapping," and sand scratches that can show up in bodywork after the paint has cured. The new gelcoat gives a "shell" back to the fiberglass part and restores the foundation for paint and primer. We bought a 1-quart container online through Ecklers Corvette Parts for about $31.
We applied two wet coats of gelcoat with a 1.8-tip spray gun. Since it's a catalyzed product, always use a respirator and preventative safety techniques while spraying.
We let the gelcoat dry overnight before continuing with more work. It will lose the glossy appearance as it dries and cures.
The new layer of gelcoat gives us one more opportunity to refine the final surface, showing us any imperfections that might rise through the paint. We are using an ultra-thin coat of Upol Dolphin Glaze to finesse the surface before applying primer.
After blocking the glaze and gelcoat, we sprayed three coats of a high-quality 2K Primer Surfacer from Upol. We sprayed a contrasting-color black guidecoat to help us level the surface with 220-, 320-, and 400-grit sandpaper as part of the process to prep for paint.
The new cover fits the car better than the original, and the larger, lower opening solves the problem of airflow to the chargecooler. The new cover will never change shape, sag, or exhibit the nasty failures that the OE cover fell victim to.
The "bird bath" is gone! The fit is outstanding and the functional front-bumper redesign wouldn't have been possible using an OEM bumper cover. ZedSled is unique with this front-end treatment, and we're proud to have a one-off custom front that looks subtle and tasteful, thanks to NPD and a few common-sense techniques.
Flex Glass front bumper, 19781981 Camaro $690.95
Ecklers gelcoat, 1-quart $30.95
Upol Dolphin Filler, 1-quart $38.95
Upol Dolphin Glaze, 1-quart $19.85
Upol 2K Primer Surfacer, 1-quart $39.30