Factory-looking sheet metal patches...

[Tom]

I'm working to replace some rusted sheet metal in the trunk of my mercedes, and discovered that 3D-printing has yet another car-guy use that never occurred to me. Turns out you can emboss or stamp patches as needed with 3D-printed die stamps. It's like a dimple die, but you can make any shape you want! For patching sheet metal, it opens up a whole new range of possibilities...

sheet-metal-stamp.gif (1.09 MiB) Viewed 1468 times

[j.samper]

Now, that is a very cool 3d print use.
Waht did you use? Pla solid?

[Tom]

Now, that is a very cool 3d print use.
Waht did you use? Pla solid?

I used something called nGen by ColorFabb, with a 50% infill and 3mm walls/top/bottom. I used the nGen only because that's what was sitting in my printer. It's similar to PET G, but prints easier according to ColorFabb. PLA would be at least as good for this, since it's so stiff, and there are lots of people online who use nothing but PLA for these types of stamps. I'm working on doing a much more complicated patch panel, and will post it here when done.

[Tom]

So I'm now very deep down the rabbit hole of making sheet metal stamps vs. actually fixing the car. Once I realized you can make dimple dies on the 3D printer, I figured what's stopping me from making the whole patch panel to match the contours of the rusted area. Many hours of Fusion 360 work and about 30-hours of printing later, I now have stamps to make virtually perfect replicas of the parts I need to cut out.... I'll post more as I go. Putting that patch panel down on top of the rust and having it match virtually perfectly is car-guy Nirvana for me. There's a little room for improvement here and there, so this isn't the final patch piece, but it is proof of concept and clearly good enough as is for any sane person....

stamps-for-trunk.jpg (1012.99 KiB) Viewed 1235 times

stamps-with-metal.jpg (878.77 KiB) Viewed 1235 times

trunk-rust.gif (1.35 MiB) Viewed 1235 times

patch-in-place.jpg (1.17 MiB) Viewed 1235 times

[j.samper]

wow!
That is impressive

[911R]

I think it is what the aftermarket uses to make metal parts.

I say it works really well on cars that will never be judged in a Concurs event. That is most of us as we want good rust-free metal panels. We improve the cars for the future. We aren't looking to be the Monterey "Best of Show" car.

[Tom]

I think it is what the aftermarket uses to make metal parts.

I say it works really well on cars that will never be judged in a Concurs event. That is most of us as we want good rust-free metal panels. We improve the cars for the future. We aren't looking to be the Monterey "Best of Show" car.

My goal is to make that trunk look like it was never repaired. It's a common rust point, and most cars get functional patch jobs that look...well...patched. My goal is to make it look factory -- which is a near impossible task unless you cut the patch from a spare car or find a replacement trunk panel. We'll see how I do, but the fact that that area is covered in seam sealer from the factory should allow me cover up minor flaws.

[911R]

My goal is to make that trunk look like it was never repaired. It's a common rust point, and most cars get functional patch jobs that look...well...patched. My goal is to make it look factory -- which is a near impossible task unless you cut the patch from a spare car or find a replacement trunk panel. We'll see how I do, but the fact that that area is covered in seam sealer from the factory should allow me cover up minor flaws.

I understand. You want it as good as possible. It's a family car and needs the best restoration.

I sure admire your dedication to getting it as perfect as possible.

My Dad and Mom never owned a car that was ever good. It was the basic GM car X twenty of them.

I got one of them well after he owned it. Here it is in the UGA parking lot (the stadium in the background). It had my "Doc" name on the front plate even back then: