Real rust grown on a 3D printed robot

Oct 12, 2026 Last reply: 1 hour ago 2 Replies
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Weathering a printed model with rust is usually a compromise: a premixed sludge gets brushed on, sits on the surface, and tends to come out looking uniform, like pigment powder. This build tackles that head on by growing actual rust on the model itself, and the finished result is a large bipedal robot with a rounded torso, long arms, big mechanical hands and treaded feet, covered in orange rust and dark metallic finishes.



The method is refreshingly simple. Dry steel wool gets laid directly onto the model and sprayed, left anywhere from one hour to overnight, then ripped off. The areas the wool touched have turned to rust. The maker reports that 3% hydrogen peroxide works great for this.



Two things stand out to me. First, rust that forms directly on the model bonds to it, unlike a premixed sludge. Second, the direct approach gives colour variation across the surface, and the close-up work here shows thick, textured rust over the painted areas, plus a nice contrast between the rusted limbs and the cleaner metallic torso plates.



Open questions remain: the printer and resin used for the robot itself have not been shared, and the robot's identity is not stated either. The maker also joked that this machine needs an oil can and that a character should look after it better.


The rust on those limbs looks properly grown into the surface rather than painted on top. One question about the process: when the steel wool is sitting on the model waiting to work, how long is it left in place? And which strength of hydrogen peroxide does the maker use for spraying?

The maker has covered both points. The sprayed wool stays on the model for between one hour and overnight, so there is some room to experiment with timing. For the spray itself, the maker says 3% hydrogen peroxide works great for the technique.

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