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Paint & Body
1969 Chevelle Metal Transplant
When Rust Takes Over, You Have To Cut It Out
May 1, 2008
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1969 Chevelle Metal Transplant
This was our rot-ridden starting point; over this Chevelle's life, moisture had collected in between the lower rear quarter-panel and its juncture with the outer wheelhouse. Left unchecked, rust ate all the way through the factory sheetmetal and started to work on the underlying structure. Dig the big chunk of old body filler along the panel edge (arrow); this was sanded away before cutting commenced.
Studio Auto Body's Hector Valdivia began by cutting away the rusted remnants of the panel edge. The idea here is to cut as little as possible, but to also make sure that all the rust is cut away; you don't want to leave any of this cancer behind to spread to the new panel. Note that part of the quarter-panel is still attached to the outer wheelhouse; we ground down the factory spot welds that attached the two then removed this piece as well.
With the last scrap of the old quarter-panel edge removed, Valdivia media-blasted the inner structure, aka the edge of the outer wheelhouse, revealing just how deep the rust damage had progressed.
We note for the record that a reproduction patch panel is available for the rust-ridden area in question, but in many cases-including this one-Studio prefers to fabricate the pieces in-house using 20-gauge cold-rolled steel. Valdivia began by placing a piece of steel against the remains of the original structure and tracing its shape onto the new panel with a pencil. He added 1/8 inch to each side before cutting, allowing extra metal to work with.
We're skipping ahead a bit, but Valdivia basically trimmed and fashioned the new piece of metal until it was the right shape and size-only then did he cut away the rusted section of the wheelhouse. He attached the piece with a few spot welds, then welded around the edges, working in short spurts so as not to overheat the metal.
The inner structure rehab continued with a second slice of sheetmetal, which was bent into shape before being placed against the outer wheelhouse. Again, he used a pencil to trace the pattern onto the steel.
He cut the resulting piece to size with a pair of metal shears. Valdivia points out that these tools come in both left- and right-handed versions; which one you use depends on which direction you're cutting in.
Again skipping ahead, he trimmed and formed the second piece until it fit right into the vacancy in the edge of the outer wheelhouse. He welded it into place, and in surprisingly short time, the underlying rust damage on this Chevelle was eliminated.
The rear quarter-panel patch replacement was performed much in the same pattern as the outer wheelhouse repair. In this shot, Valdivia had already cut a piece of sheetmetal to size, traced the factory character lines onto it, and made the necessary bends. With the piece held in place, he traced the outlines of the factory wheel opening contour onto the metal.
With the shape sketched into place, he then worked the piece on an anvil-in this case an I-beam-to fashion the actual contours. Work like this, creating metal shapes to match the factory pieces, takes metalworking ability and knowledge of the car being worked with-our talent for this case has been at it for 15 years, and it shows.
This is just one of many test-fittings, as he matched the patch panel up to the original quarter-panel then returned to the anvil for minute adjustments. At this point, some minor mods remained to be made on the character lines, but the wheel opening contour is right on.
Once the patch panel met with his approval, he formed the lower curve to match the quarter-panel shape, clamped the piece into place, then MIG-welded it in for good. He then cut out a new quarter-panel lip, which was spot-welded to the new outer edge-recreating the factory structure. The seam between the two pieces was then welded, and just like that, the patch was in place.
The last step was to grind down the welds, being careful not to obliterate the wheel opening contour, and also to shape the overhanging lip to match the original pieces. There's some finishing work to be done in this area, but the bottom line is that this part of this Chevelle is rust-free and looks like new.
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