How To Repair Fiberglass Hood

In this update the rough trunk work continues in preparation for sending the car out to have the last torso work and paint completed. This time the focus turns to the hood, t-tops and doors where some additional fiberglass repairs are made followed by the application of an epoxy primer intended to seal the fiberglass in preparation for the sanding primer.

Many of these repairs are similar in manner and purpose to those outlined in the previous update. The full general arroyo has been to make the necessary fiberglass repairs, utilize body filler to even out whatsoever crude or uneven surfaces, block sand the entire surface, make clean the area, and so employ a coat of epoxy primer.

Prior to my ownership of the car the edges of the hood were damaged in several locations. The edges of the hood were cracked and fractured and the "lips" along the rear edge of the hood were broken off. For a long time I debated just ownership a new hood only the thought of spending $700+ wasn't very appealing. I also wasn't sure a new hood would fit right in the existing hood opening. So, I made the decision to repair the damaged area. After all, information technology'due south not similar I haven't done fiberglass repair before.

So, to start, repairing the impairment required separating the hood skin from the underlying frame. Once again I used a combination of estrus, putty knifes, and a hammer to carefully separate the parts.

Once the hood frame was separated from the hood skin the damage became fifty-fifty more than apparent. In the photo below you tin can see the damaged corner and, along the edge of the hood, you can run across that the lip is gone leaving just the exposed edge of the hood skin. My goal was to reconstruct the corner of the hood and rebuild the lip along the edge of the hood to requite the hood skin the strength and rigidity it needs. Piddling did I know what a jumbo pain this would turn out to exist…

To repair the hood skin I decided to use the hood frame as a male mold. I taped some paper-thin to the corner of the frame and then applied several layers of fiberglass matt and resin to the mold.

After applying the fiberglass matt and resin I placed another layer of paper-thin on the top and, as yous tin run across below, weighed the cardboard down with some very specialized heavy objects. To keep the fiberglass from sticking to the cardboard I covered the entire surface of the paper-thin with clear packing tape.

Here's the fiberglass repair piece after removing it from the mold.

…and after doing some initial trimming and sanding the repair piece.

Afterwards test plumbing equipment the repair slice, and giving it a thorough cleaning, bonding chemical compound was applied to the piece.

Clamps were and so used to hold the repair slice in place until the bonding compound cured. Hither I'yard using the hood skin and the hood frame to sandwich the repair piece in the centre of the two. A piece of cardboard was used to prevent the hood frame from being accidentally bonded to the hood peel.

And hither information technology is, the repair piece bonded in place. At this point you can probably see what I'g going for. I'm using the repair piece every bit a backing plate so the repairs on the outer surface of the hood have something to be placed confronting. Although this repair does give the hood skin a bit of extra thickness it doesn't unacceptably affect the fit of the hood frame.

Hither'southward the top side of the hood ready to receive some additional fiberglass matt and resin. You can also see that the fiberglass repair slice does a good job recreating the lip of the hood.

In addition to the damaged corner, the cowl of the hood pare was also quite flimsy. I decided to utilize a few layers of fiberglass to strengthen the area a bit.

In addition to repairing the hood skin I as well had to reattach the encompass plate to the hood frame equally shown below.

After a lot of fiberglass work, and the awarding of some body filler, here's what the underside of the hood skin looked similar. Ultimately, I determined that the repair piece worked well to repair the corner of the hood. However, a different approach was needed to recreate the lip along the curved border of the hood cowl. After trying unsuccessfully several times to recreate this lip from fiberglass I decided to simply use some tiger pilus torso filler (trunk filler mixed with fiberglass strands) to build upwards the lip of the hood. After numerous applications of the tiger hair torso filler, followed past some surface coats of regular trunk filler, I had the repair pretty well feathered out and looking good. It's not the nigh elegant solution, but it'southward effective, was relatively easy, and it looks decent.

Here'due south where things went a flake downhill. I knew that the hood skin and hood frame needed to be bonded dorsum together. I as well recognized that the concluding shape of the hood would need to friction match the profile of the front fenders. However, the two didn't want to line upwardly very well on their own – the hood frame was as well low at the high point of the fenders.

So, I decided to shim up the underside of the hood frame with some blocking at the high points of the fenders. Clamps were also used to hold the two ends of the hood peel down so they were tight to the frame. I also used some self adhesive felt pads, the same type you put on the bottom of furniture legs, to maintain an even gap along all edges of the hood skin.

After playing around with the blocking the fit looked proficient so I removed the hood skin and cleaned all the bonding surfaces with lacquer thinner before applying some epoxy adhesive.

In addition to the clamps and blocking, I as well installed some punches between the hood and the ceiling of the garage to help develop the desired contour in the hood.

Side by side, to ensure the hood skin and and the hood frame were in tight contact I installed some screws to concur the two components together. This method of attachment was like to the one I used to adhere the rear fender to the rear prune. Without these screws there were several areas where the hood frame simply wasn't in contact with the hood skin. Unfortunately, information technology too meant these holes would need to be repaired with fiberglass later.

In one case the adhesive cured I removed the clamps, blocking, and punches and verified the fit upwardly of the hood was still OK. Unfortunately, it wasn't. At first information technology was acceptable only, over the course of a few days, the fiberglass relaxed and the hood sunk back down leaving information technology about 1/viii″ below the top of the fenders. Not cool. Rather than slap on a bunch of torso filler I separated the hood peel and frame again and repeated the process, this time building a bit more camber into the hood profile. I was less than impressed having to get through the entire procedure again but hey, stuff happens.

Yous tin imagine how much less impressed I was when information technology didn't come out right the second fourth dimension either!

So, after having gone through all that extra effort, there was no way I wanted to practice it a third time. This fourth dimension I decided to do something a chip more than drastic. On the left and right side of the hood I drilled a pocket-sized hole through the top of the hood skin into the crenel formed by the hood frame. These holes were drilled near where the hood hinges are. Next, a similar set of holes were drilled into the cavity of the hood frame near the hood latches.

And so, at each of these four hole locations, I used just enough spray foam to fill a pocket-size length of the cavity. After the spray foam had cured I drilled another fix of holes a few inches down from the holes located near the hood latches. I used these holes to fill up the two sections of cavity located betwixt the foam filler with fiberglass resin. Once cured this added resin gave the hood frame sufficient rigidity to hold the desired shape.

Suffice to say this concluded upward being a colossal pain equally well as a giant time suck. In hindsight the hood repairs DEFINITELY should take been done before installing the front clip. It would have been much easier to adapt the profile of the front clip to friction match the hood. This is because the inner fenders are quite massive and take the stiffness and rigidity necessary to agree the front fenders in the desired profile.

And so, afterward all that extra work, the many spiral and drill holes were repaired with fiberglass matt and resin. Adjacent, body filler was applied to provide a smooth and compatible surface finish. Several coats of body filler were applied and, post-obit each coat, the surfaces were block sanded to feather the torso filler into the surrounding fiberglass.

I addition to addressing the exterior surface of the hood the inside surface received a similar application of torso filler to provide a uniform surface flush with the lip of the hood skin, and to smooth out a few other rough areas.

In addition to the hood the t-tops and doors were as well prepared for primer. In the instance of the t-tops the first chore was to remove the hardware and trim and then strip the old paint.

With the trim removed Citrustrip was used to strip the layers of old paint. To aid the procedure forth a stiff bristle brush was used to scrub the surface of the t-tops well-nigh thirty minutes after applying the pigment stripper.

After scrubbing the surface, and allowing the stripper to sit for some other xxx minutes, a putty knife was used to gently scrape the surface make clean.

Afterward about 3 applications of the Citrustrip hither's how the t-tops looked. I was fairly happy with the result but found the greyness primer was being exceptionally stubborn. Rather than go on with the Citrustrip the surface was thoroughly washed with soap and water, and then with mineral spirits, to ensure all of the stripper was removed. Once cleaned the surface of the t-summit was block sanded to remove the remaining primer to expose the underlying ruddy primer and fiberglass.

Since the doors had already been stripped and sanded previously everything was now gear up for primer. Consistent with the rest of the work completed to engagement the parts were primed with white epoxy primer from Southern Polyurethanes. Several coats were applied to each office to provide a adept blanket that completely sealed the fiberglass surface.

Overall the primer came out very well. I've constitute the Southern Polyurethane primer sprays easily, coats well, and provides a overnice finished surface.

Adjacent on my to-list is to reattach the hood and doors, consummate a few odds and ends, and then become the car drivable so it can exist more easily transferred to the paint store. While the automobile is in the paint store I'll focus on the interior pieces and getting those ready for when the automobile is back from the shop.

Only, that's it for this update. Stay tuned for more updates!

If y'all have any questions about this update, or a project you're working on, I encourage you to visit the Corvette Restoration Forum and ask your question! I'm there fairly ofttimes and, together with the other great forum members, you're sure to go some great advice and feedback.