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Person welding a truck cab corner.
Person welding a truck cab corner.
Turning a Corner
Lower Cab Repair Options For Your 1960-66 C10
BY RYAN MANSON IMAGES BY THE AUTHOR
I

t’s not uncommon to find sheet metal repairs necessary on a classic truck cab. Years of use combined with Mother Nature can result in some pretty nasty situations. Trapped dirt, debris, and moisture can wreak havoc when it comes to the state of the surrounding sheet metal, resulting in rust and cancer. Unfortunately, repairing said damage can be labor-intensive and in some cases require a specialized skillset.

When we sent out our 1964 Chevy C10 cab to get blasted, we knew there was going to be some problem areas revealed. But when it came back in all its bare metal glory, we were shocked by the amount of damage that was actually hiding underneath the years of paint- and bodywork. We set our sights on the worst first, tackling the A-pillar and rocker repairs, before turning our attention to the cab corners. Both corners were pretty bad and would need replacing, a common find on these trucks. Thankfully, we wouldn’t have to fabricate these panels from scratch as Auto Metal Direct (AMD) offers stamped replacements made from factory-matching 19-gauge steel. We’ve seen cheaper crash part panels and have fought their installation in the past. The quality and fit of the AMD parts are far superior, bar none.

With the new patch panels in hand, we began to carefully plan how to tackle the repair. Naturally, the biggest thing to avoid is removing too much material from either the existing sheet metal or the patch panel, so cutting things to fit is of utmost importance. Trimming on the excessive side and sneaking up on the final size is the best way to avoid this. From there, it’s all about getting the panel to fit the shape of the cab without too much tension being in the panel. It should fit without any force in a relaxed state. This can be as easy as a little hand-shaping or require more advanced techniques like an English wheel or a shrinker/stretcher. Once shaped, it’s a simple manner of welding the new to the old and sanding everything down, followed by a little hammer and dolly work for good measure.

While this type of repair can be a bit daunting for the inexperienced (and experienced alike!), it isn’t beyond the average homebuilder with a little bit of bodywork experience and a firm handle on welding sheet metal. These type of labor-intensive jobs are what can drive a body shop bill into the tens of thousands and is something that most can actually accomplish at home with a handful of tools, a little bit of talent, and a LOT of patience.

Blasted truck cab corner revealing rust.
1. After blasting the cab, two things became obvious. One, someone’s been here before us to make repairs, and, two, years of detritus gathered within the cab corner has done its fair share of damage.
Extensive rust damage in lower cab corner.
2. The outer sheet metal is attached to the inner shell by a series of spot welds. These can sometimes be hard to find, but by sanding the surface, the low spots and, hence, the spot welds are revealed.
Blair Equipment spot weld cutters and packaging.
3. The easiest way to remove these spot welds is by using a specialized tool like these Spotweld Cutters from Blair Equipment. They work by cutting out the spot weld from the outer layer without damaging the sheet metal underneath.
Drilled out spot welds on cab corner.
4. Here, we’ve drilled out the spot welds from the outer, damaged panel.
Stamped steel AMD cab corner repair panel.
5. While we could fabricate a new cab corner from scratch, that would be a pretty labor-intensive project. Instead, a new cab corner repair panel from AMD (PN 480-4060-L) was ordered. These are stamped using 19-gauge steel and EDP coated to prevent rust and corrosion.
Mocking up repair panel over damaged area.
6. The AMD panel provides plenty of extra sheet metal, making it perfect for repairs, both large and small. While we likely won’t use the entire section, we will mock it up in place to get an idea regarding fit and where to cut the damaged panel.
Cutting out damaged sheet metal with grinder.
7. With the new panel’s coverage noted, we can get to work cutting out the damaged section of the cab corner. Masking tape works well for marking cut lines since it’s easy to see and follow.
Cab corner with rotted section removed.
8. Note that we’ve only removed enough material to leave behind undamaged sheet metal and nothing more.
Sanding edges of cutout to bare metal.
9. Next, the edge of the section to be repaired has been sanded down to clean bare metal to ensure our weld is contamination free.
Smoothing the sheet metal edge with hammer.
10. A little hammer and dolly work on the edge is also necessary to ensure it’s nice and flat.
Patch panel held by Clecos.
11. Clecos are a sheet metal worker’s best friend as they work great to secure oddly shaped panels in place with only a few small 1/8-inch holes.
Installing Cleco fasteners with specialized pliers.
12. One in the back …
Cleco on front edge.
13. … and another at the front hold the fullsized panel temporarily in place.
Inspecting panel alignment and fitment.
14. With the panel in place, a few final looks at its fit and we’re ready to start trimming.
Scribing the cut line on the panel.
Trimmed patch panel ready for shaping.
15-16. Since we’ve already cut away the damaged area and with the repair panel Cleco’d in place, the shape of the panel can be scribed from inside the cab, giving us our final size.
Testing fit of the shaped panel.
17. We cut the panel to shape on a Beverly shear, starting slightly larger than the scribe line showed, patiently trimming to get the final fit. This can be a slow process, but care at this point will prevent us from having to fight a gap that’s too large or a panel that fits poorly.
Checking curvature gap between panel and cab.
18. The curvature of the patch panel is close but needs to be finessed slightly so as to fit the cab corner without any tension in its shape. While we could start tacking the section that does fit and work our way toward the middle of the cab, clamping the two panels as we go, it’s preferable to get the panel to fit without any tension in a relaxed state.
Shaping the panel using an English wheel.
19. To do so, we used a variety of methods, from our bare hands to an English wheel. This gave our panel the correct shape, allowing it to fit in the cutout section of the cab without any tension.
Final check fit with clamps and Clecos.
20. Here, the panel is clamped and Cleco’d in place for a final check fit.
Selection of body hammers and dollies.
21. A variety of hammer and dollies were used throughout our various cab repairs.
Punching holes in panel for rosette welds.
22. To mimic the factory’s assembly method, we’re going to spot-weld the new panel to the inner structure, as well as butt-welding the panel to the existing outer sheet metal. Since we don’t have a spot welder, we need to improvise by Rosette welding the two panels together. This is accomplished by first punching a handful of holes in the outer panel …
Welding panels together through rosette holes.
23. … and then welding the holes solid once in place. Done correctly, this effectively welds the two panels together, similarly to how the factory accomplished this.
TIG tack welding the panel seam.
24. Welding the sheet metal sections together is a little more difficult. Patience and a good eye are required to ensure the two panels remain aligned while they’re welded together. Here, the panel has been tacked in place using a TIG welder.
Finish welding the seam in small segments.
25. To avoid putting excess heat into the panel and thereby causing more movement in the sheet metal than necessary, welding is done in small sections, moving around the panel to keep the heat from building in one spot.
Hammering the weld seam for stress relief.
26. A little hammer and dolly work is to be expected, but by working slowly and carefully, excess metalwork can be avoided.
Completed and sanded cab corner repair.
27. With the weld fully sanded, our repair is complete, bringing some much-needed strength back to the lower cab corner.
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