Front Clip Installation: Part 4
After months of work on the Corvette this update will conclude the installation of a new one piece front clip. So far the clip has been dry fit and trimmed for correct alignment and partially glued in place. Work in this update focuses on finishing the process of bonding the front clip in place, installing a new front valence panel, filling temporary screw holes and cutting out the headlight openings.
As you may recall, the bonding surfaces for the inner fender skirts were identified and rough sanded during the dry fit process. Now, with the fender skirts properly aligned, clamps were used to hold the parts in place while the edge of the bonding flange was traced onto the fender with a black magic marker. These marks will serve as a guide and indicate where adhesive should be placed.
After laying out a bead of adhesive the fender was repositioned and clamped in pace overnight. Each fender skirt was completed separately to keep the process manageable. No sense in rushing through and making a mistake. So far I’ve been fortunate and haven’t had to pull anything apart. I want to keep it that way!
Through this process I’ve come to realize that no reproduction fiberglass parts, whether they’re press molded or hand laid, fit exactly as they should. All of the pieces I’ve bought have required a bit of ‘coaxing’ to fit properly. The fender skirts were no exception. A few small blocks of wood had to be wedged between the tire and fender skirt to hold the front and rear walls of the skirt in position while the adhesive cured. Without doing this the fender skirt simply wasn’t in the right place.
It’s important to note that, when it comes to locating the fender skirts, I wasn’t able to find any dimensions saying where they should be located. Instead, I used my judgment which actually turned out to be pretty easy. Consider, for instance, the rear wall of the fender skirt. If you push it too far backward the top of the rear wall bottoms against the underside of the hood surround and the rear wall starts to warp and curve – you don’t want that. On the other hand, if the rear wall is too far forward, the bonding flange at the side of the skirt won’t be in contact with the fender (the fender flares sharply outward at this location). Instead, move the rear wall just far enough backward so that a good seal is formed between the gasket at the top of the fender skirt and hood surround. As a final check, and before bonding anything in place, install the wheels and turn them full right and full left to verify you won’t have contact between the wheels and fender skirt. Selecting the proper vertical alignment of the fender skirt is fairly easy as well – you need to match the curves of the fender skirt with the curves of the fender.
Another extremely important step is to verify the vertical alignment of the hood surround relative to the hood before bonding. The top of the skirt is bonded to the edge of the hood surround and, while the front and rear edge of the hood can be adjusted up or down through shimming the hood hinge or adjusting the hood striker plates, now is the time to verify the hood and hood surround are flush at the midpoint of the hood. Once bonded in place you’ll have little opportunity to adjust the fit. But, before you check the fit in the middle of the hood, you need to verify the hood and surround are flush at the nose and wiper cowl first.
As shown in the previous update I used a punch wedged between the hood surround and the garage ceiling to force the hood surround downward so it would be flush with the hood. It worked very well for my needs since only a small adjustment was necessary (about 1/8″). If you find a major adjustment is needed you may want to double check all other areas before forcing the surround in place. The action of forcing the surround downward causes stresses to develop in the body. Over time these stresses can be relieved through cracking or body ‘creep’. Both are undesirable and should be avoided. The point is, using a bit of force is ok, but don’t overdo it.
Below is a photo showing the inside edge of the hood surround. You’ll see that, in addition to using the punch from the ceiling, several temporary screws were used to help clamp the two panels in place. Once the adhesive was in place the parts were allowed to cure for a full 48 hours before the clamps were released and the temporary screws were removed. Normally 24 hours would be ok, but I didn’t want to take any chances given the critical nature of these areas.
As you can probably tell, it’s imperative that you dry fit all of the parts ahead of time. Although it wasn’t hard to figure out how everything was supposed to fit up, it did take quite a bit of tweaking to get it where I wanted it. Going straight for the adhesive would have spelled disaster for sure. If I’ve learned anything while installing this new one piece front clip it’s that patience is key. Take your time and, if it doesn’t seem right, it probably isn’t.
With the front clip now fully bonded in place one of the final steps was to install the new front valence panel. Thankfully, the front valence fit much better than the rear panel!
After painting the interior facing surface of the valence panel (to match the engine compartment) the two bonding strips were fit up and bonded in place using the same epoxy adhesive used elsewhere on the new one piece front clip.
After curing the adhesive the valence panel was fit up to the front clip. During my dry fit I noticed the fenders were a bit further out than they needed to be. To fix this a set of tie downs were run between the radiator support and hood and then tightened slightly. The tension in the straps sucked the fenders inward and allowed me to achieve a reasonable gap between the edges of the fender and the new valence panel. This fit-up was actually done before the inner fender skirts were bonded in place. Once the fender skirts are bonded in place this type of adjustment is no longer possible. This is yet another example of the importance of dry-fitting EVERYTHING in place first.
With the new valence panel successfully dry fit it was bonded in place. At this location a bit of extra ‘persuasion’ was necessary to achieve a square joint. As a result the clamps I typically use simply weren’t able to provide enough pressure to hold the pieces in place – hence the vice grips shown in the photos. You’ll also see that no screws were used here. Everything was accessible with clamps so why drill holes if you don’t have to!
With the new front clip fully bonded in place all of the temporary screws were removed and the remaining holes filled using a specialty repair adhesive. Detailed information on this procedure is provided in the final Rear Clip Repair update.
At this point the new front end was looking pretty good – it was starting to look like a Corvette again! The next and final step in the install was to cut out the openings for the headlights and side marker lights.
The side marker lights were simple – the center of the opening was cut out with a Dremel tool and then two holes were drilled on either side to accommodate the attaching studs o the marker lights.
At the headlight openings a drill and jigsaw were used to remove the excess material. A bit of ‘extra’ material was left around all of the edges to avoid accidentally removing too much material.
Once cut out a series of square and round sanding blocks were used to remove the remaining excess material. As work progressed the headlights were temporarily put in place to gauge how much more material needed to be removed. You want an even gap around all edges of the headlamps so, even though installing and removing the headlamps was tedious, it was a necessary step to produce an even gap on all sides of the headlights.
And here it is, the new one piece front clip fully fit-up and bonded in place! All I can say is phew! It turned out to be A LOT more work than I expected but I feel pretty good about how it all came out. It really feels like I’m making progress now!
There’s no time to sit back and admire my handiwork though. Next up is installation of the front fender, headlights, grilles, and all of the trim pieces in preparation for painting. The next update will focus specifically on reinstallation of the front bumper and, if you want a teaser, it turned out to be way more work than expected. Remember that whole dry-fit thing I talked about… turns out I didn’t heed my own advice and I paid the price.
But, while waiting for the next update, why not stop by the Corvette Restoration Forum to say hello and talk Corvettes. Lastly, if you haven’t done so already, please Like this project on Facebook to receive additional progress updates and notifications when updates have been posted.