Have you ever played with Rose’s metal? It’s a fusible alloy of bismuth, lead, and tin with a low melting point of around 100 °C. Historically, it’s been used as a solder for cast iron railings and things, and as a malleable pipe filler material to prevent crimping while a pipe is bent.
[Ben Healey] has been playing around with Rose’s metal and some PETG printed molds, making everything from Star Wars Imperial credits to chess pieces to leather stamping tools. In the video after the break, [Ben] takes us through the process, beginning with mold-making from STLs — something he picked up from another YouTuber.
He recommends adding registration marks to multi-part molds in order to keep everything lined up, and adding a small recess in the seam for easy separation with a flat-head screwdriver. So far, the molds have held up to multiple pours, though [Ben] did print them rather thick and is glad he did.
As far as making liquid metal, [Ben] used a cast iron pot with a convenient pour spout, and a blowtorch. He added graphite powder to the molds in an effort to make them give up the goods more easily. To finish the pieces, [Ben] cut the flashing with tin snips and used sandpaper and a Dremel to smooth the edges. Copper plating didn’t work out, but [Ben] is going to try it again because he thinks he screwed something up in the process. He’s also going to try printing with TPU, which we were just about to recommend for its flexibility.
There are many ways to cast metal on the (relatively) cheap. Have you considered Kinetic Sand?
20 thoughts on “3D Printed Molds For Casting Rose’s Metal”
Another thought rather than printing TPU would be to print the positive and then make a mold from silicone.
I already do this using two part silicon putty and lead free pewter.
I was getting a very strong Andy Dwyer vibe from this guy.
It evens out the game when you give the chess player with white pieces the ones that are made with lead :)
Where’s the Rose’s Metal filament for our 3D-printers?
Pellets? To avoid filament snapping in the PTFE tube?
On a handful of parts? You’ll be fine. You’ve gotten more lead exposure soldering. This is a nice project, and perfect fodder for folks looking for something to pick at.
See also https://hackaday.com/2015/12/27/pewter-casting-with-pla/
This is super interesting! Never occured to me to try quenching hotter metals, maybe next time.
There is also a similar alloy “Cerrotru” that is lead free.
Cast pretty nicely even with MDF mold.
There is also an low temp alloy “Cerrotru” that’s lead free, melt at 138C.
Cast nicely even in MDF laser engraved mold.
meybe put metal to form and form put to inside ice.
(Second time posting this warning….)
Using sandpaper and/or a Dremel is going to create a lot of dust. Rose Metal is around 25% lead. Creating lead dust is generally a bad idea and can lead to health issues, this is also illegal in some areas.
Good note! Wearing PPE and sealing the parts after they are done are important. Also doing everything outside, and washing hands thoroughly too.
Any sandpaper or things used should also be thrown away and not used for anything else.
Is this the same metal used in the Metal Molder Die-Cast Factory – http://www.samstoybox.com/toys/MetalMolder.html -? I still have mine!
I use old silver coins and sterling sometimes… The detail you can get with a resin print and delft clay is pretty awesome.
I have had much luck using metal powder infused resin. You get the strength of the resin with the weight of the metal. You can use brass, aluminum, etc…
It’s a shame this is so expensive. Twenty bucks for three cubic inches means you’re not exactly going to be making a collection out of this stuff.
Depends where you live, as most of the cost is often from shipping stuff around.
rotometals.com sells 65’C lead-free Field’s Metal, and I was happy with some other stuff we bought from them.
when you leave the world of cheap plastics… things can get pricey very quickly ;-)
I’ve poured molten copper directly into both SLA and PLA prints. Idea is you create a minimal shell and bury it in sand. Hackaday covered it: https://hackaday.com/2016/07/20/metal-casting-with-single-shelled-pla-masters/
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