Transforming Rust Into Sheet Metal Origami

“Nana jorobi, ya oki”

-the original version of this Japanese idiom, likely coined by someone who was getting their posterior pummelled by their project

Like all DIY restorations, some things happen fast and easy, while others take longer forever and prove difficult impossible. Sometimes these situations are simultaneous. As I alluded to in Part 2, when I bought this truck the rear quarters were one of the areas that I knew would be challenging. They were rusty on the extreme ends like many 70 series, and would need some serious attention. I am no kind of technician, and thought of it as a good opportunity to acquire some new skills.

This might be a good place to remind you that the frame, suspension, and the balance of the underside of the truck was already sand blasted, and coated. I mention this, because the *before* pictures you are about to see may be considered shocking, and lead you to believe the truck was a rusty pile.

POR15 combined with media blasting turns old into new

Such was not the case. The floor was intact, both from inside and outside. The recessed cavities that I explored with a flashlight on the advice of an expert (under rubber access plugs) were pristine. The door bottoms were almost all perfect. Aside from the corners of the rocker panels, and a little bit of surface corrosion common on any 30 year old truck, the damage was limited to the rear corners, hidden behind the bumper end caps. I believe this was why it had progressed so long unchecked by the previous owners, since the rest of the truck appeared to have been looked after. Nonetheless, the lower quarters were seriously compromised. The right hand side had a decent hole, but the left hand side was actually corroded away to the point where there was metal missing.

Okay, brace yourself. Here is what we started with, once the flares, mudflaps, and bumper ends were removed. (Yes, I knew the extent of the damage before I bought it.)

Patch panels for the HZJ77 are not widely available, given that the vehicle was only made for the Japanese market. But even when I broadened my search to include the 76 and LJ78 models, nothing seemed to be available. Eventually, I realized I’d have to make them myself.

How Hard Can it Be?

It’s only metal. Right? Wrong. Add multiple bends, curves, and folds in all directions, and you have a 3 dimensional piece that ends in professional help, either from a bodyman, or a psychiatrist. At the time of writing, I’m close to the latter.

The right hand side went surprisingly quickly. It was the very first piece I bent. The first piece I ever welded. It was a hand-formed piece of steel that I created from 18 gauge stock, and would be difficult to spot once it had been set in place with special (read: EXPENSIVE) panel glue. It’s invisibility is largely owing to the fact that it would eventually sit below the bumper end cap, but still! So far I couldn’t see what the fuss was about – sheet metal forming didn’t seem that hard?

I felt like a savante – a sheet metal whisperer. All those naysayers who swore off bodywork as some kind of black art? They didn’t know what they’re missing. 

Or did they?

The subtle art of not giving… Up. 😉

The left hand side was a whole other story. I began with the misconceived notion that cutting out the least amount of metal possible was the way to go. Using a flap disc on my grinder, I excised the rust, peeled back the layers until I uncovered bare metal, and cut out the offensive oxidation. Then I realized the err… beauty on this side ran more than skin deep. The inner rocker had some holes, and the rust had crept into the lower wheel well.

Time to employ some more of my newly acquired fab fab skills? Not so fast. This was not just a few nips and tucks. This was moving into the structure of the lower rear corner. I regrouped, researched, reset, and started cutting. And cutting. The lower wheelwell edge wasn’t too hard to create. (A mirror-imaged picture of the opposite side helped with the visuals, although it reminded me of just how much of a poseur I really was.) The lower inner rocker edge went similarly smoothly. Knowing it would all be hidden actually took some of the pressure off, and allowed me to simply shape functional pieces. I also did them in three stages, so I could preserve the original dimensions of the next step as I went.

To say my confidence was bolstered at this point is an understatement. I was flushed with success and anxious to finish sealing up the back end altogether.

The (body) Hammer Drops

Just one more panel to make, right? Easy peasy. Attempt number one took a few evenings, and once I was able to step back and look at it, I realized it looked exactly like what it was: An amateurish patchwork of butt welds, wavy bends, and imperfect fitment. So I started again. This time I tried doing it in three pieces, to accommodate some of the more complicated bends that I wasn’t getting in two pieces. Over three weeks, including weekends, it consumed my spare time. I even made a paper template. For this rig, perhaps I should have called it origami? I went through a myriad of cutting discs, several flap wheels, and many meters of flux core wire. When I was “finished” I mocked it in place, and was dismayed to find that it was no better than attempt number one. Possibly worse? It was heat distorted, overworked, spattered, and generally well-named as a PATCH panel.

Less is more? Or in this case, more is less?

Doing something the exact same way for the third time would seem an obvious mistake. And admittedly, I was about to start over and do exactly that. But suddenly, just yesterday it came to me that cutting out more metal might actually make less work. It did give me pause, since I was about to lose the factory curve that passed under the rear taillight. And I’d be making a new one from scratch. Oh boy.

I did buy a panel flanger, that would create a mating surface when two panels come together. But ultimately, starting over was the key. I made an entirely new panel, including the curve under the tail light, in just a few hours. It ended up being much tidier than the patchwork that I’d spent three weeks agonizing over. One panel, one piece of metal: Job done.

Rather than giving up (and farming it out to a “professional”), I simply needed to stand up that last time. Or, as the Japanese saying goes: “Nana jorobi, ya oki” – Fall Seven Times, Stand Up Eight.


In the next entry, I hope to glue these panels in with space age adhesive, and then look forward, quite literally, toward the bow of the truck, where more adventures await.

Part 1 | Part 2

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