Metal Rx: Addressing dreaded rust cancer on a 1955 Cadillac
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Dirt, salt, moisture and simply time will lead to rust—there doesn’t seem to be any way to get around it. That’s certainly true of a nearly 70-year-old Cadillac from the “rust belt.”
The 1955 Cadillac Coupe deVille featured here was located in an auction advertised last fall in Old Cars’ e-mailed “enewsletter.” A pre-sale inspection of the Wisconsin-based car by 1955 Cadillac authority Rick Payton revealed the Cadillac was complete—including complete with rust—but remained surprisingly solid and buildable considering its age and geographic location. Essentially, it was in what we on the Old Cars staff call “Wisconsin solid” condition (rusty, but not too far gone to restore). After we won the bid for the Cadillac, Payton retrieved it and parked it in his shop, The Classic Garage, in Chippewa Falls, Wis., where body guru Jan Behlke went to work cutting out the rusty metal and welding in new panels that he fabricated. When Behlke is done, the Cadillac will be about as rust-free as when it rolled off the assembly line at the Clark Street Cadillac plant in Detroit.
Like other vehicles, the areas where mid-1950s Cadillacs rust are pretty predictable, and often in the same places as other GM products of the era. Most 1955 Cadillacs have wide lower body trim that traps dirt, salt and moisture against the body’s metal rocker panels and lower rear quarter panels, causing rust to form there. In addition, water running down the rear side windows of coupes seems to drip onto the back of the rear quarter panels, slowly torturing the panel until it rusts through in front of the rear wheel opening. This 1955 Cadillac body had this typical rust-through in both of these areas.
The Classic Garage has cut and welded many 1955 Cadillac bodies into eventual Cadillac & LaSalle Club winners, and with his proximity to us, he was the man for the job. Work started with the passenger rear quarter panel as it was not only rusted but also dented, making it the worst area of the car and most challenging to repair. The following are some of the steps taken to repair the passenger rear quarter panel.
The Classic Garage 720 E Spring St. Chippewa Falls, WI 54729 715-861-3558 (Shop) 512-484-4501 (Rick Payton, owner)
This rocker is far from rockin’! Time to cut out the cancer and replace it with fresh sheet metal. If you are from the North, this is a common sight among our “seasoned” old cars stock.
Angelo Van Bogart
Grab your trusty cut-off tool and get busy. Remember, all cars are simply an assortment of assembled parts. If you keep this in mind, the project will not be as daunting nor as anxiety-ridden.
Angelo Van Bogart
Although it looks like a half-eaten Saltine cracker, the cut-out piece of ravaged metal is valuable to the process. It is the basis for fabricating the fresh, new piece. Keep this in mind while hacking away and “exorcizing” the rusted carcass. Note the holes on the edge of the new piece; these holes will come into play later in the welding process.
Angelo Van Bogart
Sit back and take stock on the rust issues and visualize the easiest and most straight-forward approach to fabricating a new piece. This is where the idea of “pieces” comes into play. It is better (and sometimes easier) to fabricate one larger piece that attaches to another piece as opposed to cobbling smaller patch pieces. Resist the urge to skimp on a larger piece of sheet metal. Note the vertical cut on the rear fender; this is a relief cut to battle warpage in the weld, and to address a dent higher up the fender.
Angelo Van Bogart
We would be remiss if we did not mention the need to attend to the backside of new, unpainted “raw” fabricated pieces. While going through the trouble of putting fresh sheet metal on our ride, it would be a shame to have it rust a few months or years after spraying a show-winning finish on her. Many companies sell a weldable coating that will let you sleep at night without the nightmares of ferric oxide ruining your baby. Make sure to coat/treat the inside body cavities, too. Rust will find a way!
Angelo Van Bogart
As Neil Young’s live album states, “Rust never sleeps!” Before the new rocker section can be mig welded up, the rear quarter panel “affliction” needs to be addressed. Also note the great care taken in reaching clean, bare metal. When using flapper wheels, take care to not fixate on one spot too long. If you blow through the thin metal or warp it, you are making more work and wasting time and money in the process.
Angelo Van Bogart
As Neil Young’s live album states, “Rust never sleeps!” Before the new rocker section can be mig welded up, the rear quarter panel “affliction” needs to be addressed. Also note the great care taken in reaching clean, bare metal. When using flapper wheels, take care to not fixate on one spot too long. If you blow through the thin metal or warp it, you are making more work and wasting time and money in the process.
Angelo Van Bogart
To get a professional and seamless weld, use a pneumatic flanger to create a backing for the new fabricated piece to sit flush against. This will assure a perfect transition between the two pieces. Such steps taken now will take hours off of future body panel sanding and give a razor-sharp perfection to the body lines when it comes to finally painting over the finished body work.
Angelo Van Bogart
If you can use a glue gun, you can mig weld! With sheet metal, the trick is to place tack welds at around an inch or two apart, give each a shot of compressed air to gently cool the weld and not warp the metal, then repeat until the panel is fixed in place. Note the “plug” welding on the bottom of the piece to the lower pinch area of the body, once again connecting the pieces to make a whole. Once the weld is to your liking, fill in all the gaps, alternating until the seam is completely welded and ready to be ground smooth.
Angelo Van Bogart
No rest for the weary! Behind the rear wheel needs attention as well. Behlke will repeat the steps he took earlier on the front of the quarter panel. Sometimes, reproduction body panels are not available, or the lines aren’t as crisp (the panels on this car are no longer available). This is why restoring classics to perfection is an art form done out of love.
Angelo Van Bogart
It looks like this spot of cancer was dealt with before with the ol’ rivet and “Kitty Hair” approach. Remember, these were once just “beater” cars. Be kind and don’t tempt karma by cussing out the previous owners — you are going to need all the cosmic help you can get to finish the project!
Angelo Van Bogart
After a bit of cutting, grinding and fabricating, you can now take solace that the job was done the “correct” way and all is forgiven. The car now sports new metal that will last.
Angelo Van Bogart
The patience with filling in the open-spot approach to mig welding really pays off in the end. The body lines are maintained and the structural integrity has been restored.
Angelo Van Bogart
In the beginning, you might have thought the rusted out heap was going to be a Herculean job, but you kept the “pieces” mentality and the car is now taking shape. Behlke has the original lines intact and crisp—just the way Cadillac intended!
Angelo Van Bogart
For smaller areas of rot, the same “cut, clean and fabricate” process also applies. When approaching these odd and sensitive areas, think of the offending areas as simple shapes of triangles, circles and rectangles.
Angelo Van Bogart
You can easily assemble these smaller pieces into a coherent larger piece to patch into solid pieces of metal on the body. With a bit of ingenuity, a mig welder and a grinder, anything is possible.
Angelo Van Bogart
Sometimes you need to get creative and “fill holes” to make the paper-thin metal work to your liking and bend to your will. As the saying goes, “It all comes out in the wash!”
Angelo Van Bogart
Just keep “tacking” until it takes shape. Grinding and sanding to the original shape will eventually reveal the marvel and genius of your hard work.
Angelo Van Bogart
Time and patience are your best friends. Before you know it, your ride will take shape and bring you the well-earned satisfaction of a job well done. Once the body is solid, the real fun begins and the true test of dedication begins.
Angelo Van Bogart
Interested in old car restoration? Here are a few more “resto” articles for your reading enjoyment.
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