An interesting thing happened while I was block sanding my bonnet center section. I found a wrinkle and a bump. The wrinkle was next to the passenger side headlight opening. The bump was next to the driver side headlight opening but closer to the power bulge. Both were subtle but block sanding reveals this sort of thing, both by observing the sanding pattern of the guide coat and just by sense of feel with your hand. A little research determined that other restorers have experienced similar problems. Since my bonnet center section is new, I am sure these developed recently. I would note that the match of the flanges of the bonnet center section to the flanges of the wing panels required some force, using clamps, to get the flanges to align. I suspect the forces placed into the panel found an outlet at an adjacent weaker point. As my friend Rick observed “the bonnet center section is like a floppy taco”.
Once I released the bonnet center section from the wings, I was able to hammer and dolly both issues away. But I was worried that they might come back. I decided to add some stiffness to the metal. The way I went about this is as follows. I purchased a can of Evercoat body filler that is mixed with short Kevlar fibers. Not many years ago, it would have been plain spunglass fibers but Kevlar is the current fiber of choice.
I applied two thin coats to the underside of the bonnet. I chose to start at a point just forward of the radiator rock screen and brought the material back to the bonnet opening. Per the directions for the product, I top coated it with a skim of regular filler. The Kevlar reinforced product is green, as shown in the following photo. Also notice that I installed the headlight chromes to hold the edge of the headlight opening in the required position. I had previously fit these so I felt confident that they would hold the required profile.
Once feather edge sanded along the edges and painted, the additional material will be very hard to notice. More importantly, I have vastly increased the section thickness and thus the bending strength of the metal in this area. Of course, there is a chance that I’ll just push the problem up into the unreinforced area. We’ll see but I am confident that the flanged edge and the more dramatic stiffening effect of the power bulge in the remaining area will serve to hold things in check.