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1950 Chevy Gets A Chopped Top- Drop That Top!Lowering The Lid On A More-Door From the March, 2009 issue of Rod & Custom By Kev Elliott
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Whether the supply of two-door cars is drying up, which we doubt but supplies are finite, or whether four-doors are just becoming more accepted, we're not sure, but we've seen a rise in the number of more-doors being modified. In fact while we were at Brad Masterson's shop shooting this feature, he had three four-door Chevys in for top chops, as well as a two-door Merc and even a Riviera. Chopping the roof on a four-door doesn't involve much more work than a two-door-obviously there are the two extra door tops, but the side window area needs modifying on a two-door anyway. The interesting part of Brad's chop is the way it was done, without cutting into the trunklid at all. Being a fastback, often the roof is lowered, then the trunklid is sectioned or pancaked to get the lines to flow, but this method involves none of that. Instead the entire trunk and surrounding sheetmetal is lowered between the rear quarters, and then this area is reworked. While Brad uses a MIG welder for some of the work, he prefers to work the traditional way with gas welding, followed by lead, not plastic filler. Blame it on the way he was taught by George Barris and Bill Hines, but he just prefers to work this way. That's not to say this can't be done entirely with a MIG, though such welds can't be hammer welded in the way gas welds can. So with no further ado, let's see how a sow's ear was turned into a silk purse...  Here's our victim, er, subject,...  Here's our victim, er, subject, a tidy four-door '50 Chevy fastback. Before any cutting could take place, the interior was stripped out completely and all the glass removed.  A framework was welded inside...  A framework was welded inside the car to prevent any movement once the roof was removed. This framework was welded diagonally in an X-shape across the car between the B-pillars, front to rear across all four door openings, as well as at various points up the B-pillar. The rear window opening was also braced.  This triangulated pattern...  This triangulated pattern was welded in the windshield opening, allowing Brad to accurately center the roof when it goes back on.  Using the beltline as a reference...  Using the beltline as a reference point, Brad marked the doors 4 inches above the line.  After taking careful measurements...  After taking careful measurements from the upper edge of the trunk opening to ensure the cut across the roof was straight, masking tape was pulled across the roof to mark the cut line.  The sail panel was marked...  The sail panel was marked for cutting next, following the driprail, but 3 inches above it, then measuring parallel to the beltline and vertically through the rearmost trim hole. The horizontal mark, if it were continued forward, would meet the window frame on the door where it starts to curve round above the window. This will eliminate the dogleg in the window frame.  The final cut line at the...  The final cut line at the rear of the car was alongside the trunk opening as pictured. Notice the trunk was tack welded to the body, ensuring nothing moved out of alignment during the chop process.  The wooden tack strip was...  The wooden tack strip was removed at the top of the B-pillars before Brad cut through this section with the acetylene torch. Note the bracing in the roof. You can never have too much bracing, but remember you'll need to be able to climb inside the car during the chop!  Brad started on the A-pillars...  Brad started on the A-pillars removing 4 inches and then moved onto the door tops. Note the door top was removed right where it joins the door itself in the rear, as the chop will eliminate the dogleg straight section that was angled toward the rear of the car.  The inner bracing behind the...  The inner bracing behind the sail panel was also removed, as were the braces behind the rear seat that support the package tray. In short, anything that will stop the roof being lowered needs to be removed.  With all the cuts made on...  With all the cuts made on their marks, the roof was lifted. You can either cut on the top marks on the A- and B-pillars, then cut the rear across the roof and around the driprails and remove the roof completely to cut on the lower marks, or do as Brad and the guys did and install temporary supports to hold the roof while all the cuts were made. This saves having to lift the roof section clear of the car, as it's heavy.  This section was removed from...  This section was removed from the sail panel next.  With all the cuts made on...  With all the cuts made on their marks, the roof was lifted. You can either cut on the top marks on the A- and B-pillars, then cut the rear across the roof and around the driprails and remove the roof completely to cut on the lower marks, or do as Brad and the guys did and install temporary supports to hold the roof while all the cuts were made. This saves having to lift the roof section clear of the car, as it's heavy.  The roof was then lowered...  The roof was then lowered into position, aligning the driprails and doorjambs as shown. Note the rear of the roof stays in place for now.  In order for the A-pillars...  In order for the A-pillars to align, Brad heated the inside of the lower section with the acetylene torch and bent them in slightly, trial and error telling him how far to go. Here you can see the temporary roof support, too.  Using the central pattern...  Using the central pattern as a guide to ensure the roof remains central, the A-pillars were aligned. It may take you a few attempts to get both perfect. The windshield posts were then clamped and gas welded back together.  The lower sections of the...  The lower sections of the B-pillars also required bending inward to align, though owing to the substantial inner structure, these had to be cut through almost all the way to the outer skin before they'd bend. These cuts were later welded up. This picture clearly shows how far the top of the B-pillar had to be moved rearward on the roof. The small section in Brad's left hand was removed from the rear and added back in forward of the B-pillar, ensuring everything appears 'factory.'  With the main section of roof...  With the main section of roof tack welded in place, attention turned to the rear, where most of the work took place. With all the cuts made, you can see how the whole rear section lays down inside the rest of the bodywork, trunk included. Chopping the car this way eliminates having to section and pancake the trunklid, but means more work in the rear quarters.  With no filler section required,...  With no filler section required, this illustrates just now nicely the roofline flows with the chop performed this way.  Having first used a MIG welder...  Having first used a MIG welder to tack the rear section in place, and with help to ensure the two sections were aligned, Brad gas welded across the roof in short sections working with Ray who hammered the welds whilst still hot, reducing warpage. After hammering, and between each section of weld, Ray cooled the metal with a wet rag, again reducing warpage.  A couple of short slits were...  A couple of short slits were cut in the curve at the sides of the roof to better align the two sections, while a small filler piece was required in the area above the driprails to compensate for the different angles resulting from the front and rear sections being laid down. With everything hammer-welded to this point, attention turned to the door tops.  With the B-pillars welded...  With the B-pillars welded back up, the door tops were rebuilt as shown, sections were removed from elsewhere and added to the tops as required. Particular attention needs to be paid here to ensuring the panel gaps are constant.  Moving inside the car, the...  Moving inside the car, the braces behind the rear seat were MIG-welded back in place at this point.  In order to complete the remaining...  In order to complete the remaining work, this section had to be removed on top of the rear quarters, immediately behind the doors.  Brad made vertical cuts in...  Brad made vertical cuts in the rear quarters, then massaged (OK, he used a hammer!) them down to meet the now lower rear section.  A new, more curved panel was...  A new, more curved panel was formed to replace that which was removed, creating the correct curve from the top of the quarter panel to the sail panel. Obviously the lower section of the latter still needs to be clamped in place for the new panel to fit.  Moving to the other side,...  Moving to the other side, you can see how much welding was required in this area when performing the chop in this manner. It's probably less than modifying the trunklid though, and accentuates the fins.  With the welding complete,...  With the welding complete, the Chevy returned to its owner for lead or filler work, but you can see just how well the shape and proportions of the chop turned out.
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