Experiments with cast solder
In portal crane project the hook has to be as heavy as possible, otherwise the threads will not be tightened enough and will skip all the time (and will look unrealistic). Making it from metal is a natural solution, however it also needs to be DIY-friendly, i.e. I need it to be doable in home conditions without specialized equipment like furnaces, kilns etc.
So I decided to try doing it with solder. I have it at hand and it’s meltable by a soldering iron at about 200°C.
As for the mold, I simply cut some holes in cardboard and held cardboard sheets together with a paper binder. I have a model of the hook in CAD, but ended up with drawing holes by hand and cutting them with a hobby knife. Don’t know how it could be made more low-tech.
The result is as ugly as you’d expect, but it seems to do its job. I sanded it with a grinding stone on a Proxxon rotary tool and covered with epoxy, in hopes to fill the dents and sand it more easily.
The horns of the hook are resin printed, so they look gorgeous compared to the metal part.
Next time I want to try something even crazier: casting solder into resin-printed molds. Stay tuned! (And a more sane approach would be to make a silicone mold, as it’s said to withstand temperatures up to 300°C).