Welding without Grinding
Another example of Volvo’s exacting standards causing a significant reworking of a process was how Bertone assembled body panels on the 780. Bertone, like most coachbuilders of the day, used basic hand tools to fabricate the sheet metal. When panels were joined they were welded and then ground smooth. This was not acceptable to Volvo because the zinc metal plating, which protected the metal from rusting, would be compromised.
Mario Panizza explained, “Volvo’s use of zinc plating meant we were not able to grind panels. It was common in the past to use the grinder to make final adjustments, but the grinding would remove the zinc plating, so all panels had to be made right from the beginning. In each shop, including body, paint, and general assembly, we had a new experience with the 780, which Bertone didn’t have before.”
So each body panel had to be formed as a single piece, correct from the beginning. Mauro Charriere explained, “We would typically spot weld a seam, and we had to learn to weld a continuous bead along a seam, that was then measured precisely.”
Paolo Caccamo spoke to this issue as well, “One of the hardest problems to get past in the manufacturing was Volvo’s desire for double galvanized sheet metal for all the coverings and all the structures coupled with the coverings. They need to have the sheets zinc-plated both inside and out, which is difficult. In 1985 we were the only one’s in Italy to have overcome the challenges that often occur with the metal during the electrogalvanization process.”
Bertone later adopted this process for all of their future produced cars.