During engine bay restoration, I came across a crack on the driver side fender skirt. It was located on the thin strip of fiberglass where the radiator support bracket attaches to the fender. Fortunately it was small, and the repair was very easy.
The crack is obvious in this picture, and hopefully the other details help identify its location.
With a 1/16" spherical engraving dremel bit, I removed the cracked and damaged fiberglass. A bright light is useful when grinding away cracked and damaged fiberglass. As you can see by the prep work, there was more to the crack than it initially appeared. The bright light let me follow the trail of the crack through the fiberglass.
Once I had the crack widened out, I placed aluminum tape on the backside. I did this repair in conjunction with the fender well seam separation repair so I could use one batch of Kittyhair. Wearing nitrile gloves, I put a little Kittyhair on my finger and pushed it into the crack. Once I had it packed in to my liking, I let it cure.
When I removed the tape, there was a little bulge where I had pushed the Kittyhair through. I smoothed it down with a small, conical grinding stone and dremel. The side shown was smoothed by block sanding, which got rid of the stray fiberglass strands and brought the repair flush with the fender skirt surface.
SUMMARY: This was a 2 out of 10. The trickiest part is ensuring all the damaged fiberglass has been removed and the crack ground out, otherwise it may grow again. Once that's done, the rest is straight forward.
Engine Bay Crack Repair