65 Radiator Shroud Nut Repair
During disassembly of my '65 restoration project, it was discovered that three of the weld-on mounting nuts for my radiator shroud were missing. The original metal shroud is mounted to the radiator support panel with six bolts, three on each side. The mounting bolts attach to square weld-on nuts that are fixed to the shroud. A new (replacement) shroud is hard to find and expensive. I decided to repair mine as follows.
The first two photos show the replacement square nuts that I used and the miniature file set that I used to replicate the markings on the original nuts. First, the hole area (where original nuts were missing) was prepared by sandblasting. The replacement nuts needed some work to better replicate the originals. As can be seen in the photo, one side of the nut is flat and the opposite side is rounded. The rounded side was carefully ground down on a bench grinder to remove most of the rounded portion. I then finished it by rubbing it across a flat file, going back and forth until the surface was flat. You could do the same thing with a belt sander; just be careful to avoid converting the nut to a missile. The original weld-on nuts have small notches on each corner. I believe these are due to the spot weld procedure used to secure them to the shroud. Anyway, I then take a small triangular shaped mini-file and make a groove in each corner of the replacement nuts. To be honest, I eyeballed the groove locations and depths. Next, the nuts were attached to the shroud using panel bonding adhesive (as used in autobody shops for panel replacement). I placed the newly ground nut surface against the shroud surface. The nuts are held in place with a clamp until the adhesive is fully cured. The last two photos show the finished product. After painting, I expect the nuts will appear nearly as original. If the nuts were to break loose, they will still be retained by the tightened mounting bolt. We'll see how it works out.
The first two photos show the replacement square nuts that I used and the miniature file set that I used to replicate the markings on the original nuts. First, the hole area (where original nuts were missing) was prepared by sandblasting. The replacement nuts needed some work to better replicate the originals. As can be seen in the photo, one side of the nut is flat and the opposite side is rounded. The rounded side was carefully ground down on a bench grinder to remove most of the rounded portion. I then finished it by rubbing it across a flat file, going back and forth until the surface was flat. You could do the same thing with a belt sander; just be careful to avoid converting the nut to a missile. The original weld-on nuts have small notches on each corner. I believe these are due to the spot weld procedure used to secure them to the shroud. Anyway, I then take a small triangular shaped mini-file and make a groove in each corner of the replacement nuts. To be honest, I eyeballed the groove locations and depths. Next, the nuts were attached to the shroud using panel bonding adhesive (as used in autobody shops for panel replacement). I placed the newly ground nut surface against the shroud surface. The nuts are held in place with a clamp until the adhesive is fully cured. The last two photos show the finished product. After painting, I expect the nuts will appear nearly as original. If the nuts were to break loose, they will still be retained by the tightened mounting bolt. We'll see how it works out.
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