If you start sintering a bunch of crap, or otherwise start running a kiln a lot, you may wish to know what the *actual* interior temperatures look like.

I rigged up a thermocouple on a Particle Photon, to independently measure and record temperatures. The kiln has an independent digital display based on its own thermocouple, but I can't record those values beyond pen/paper (which is obviously tedious)... and I'd still want some way to independently verify the internal temperatures.

Having an external thermocouple also lets me bury it in refractory to get some sense for heat penetration and transfer delays.

There are a few common ways to age or force "natural" patina onto bronze and copper alloys.

  • Bright green verdigris: copper carbonate
  • Dark green verdigris: copper II acetate
  • Dark brown or black shading: ?? (some sort of copper sulfide?)

The verdigris can form spontaneously just from cleaning, and will "stick" best to very clean (polished) bronze. They can be prevented with light waxing, and can wipe off with a soft cloth.

The darker color, as an "oil-rubbed bronze" finish, is an integral part of the surface material and can only be removed with aggressive wire brushing, sanding, or other surface removal.

skulls with various finishes

Note: this is an addendum to the 3rd step of a print / sinter / polish process.

Solid bronze can be finished and polished to a bright luster, not unlike jewelry. It's a very hard, beautiful metal with some cool properties. It cleans up similar to metal-filled plastics, but there are a few steps specific to solid metals.

tl;dr: pickle, brush, shape, tumble, maybe brush again, polish, buff, wax.

Note: this is step 3 of a print / sinter / polish process.

Now that you've successfully printed with "metal" filament, and possibly sintered a solid metal part, you want to make it look nice. These steps are generally chronological, but you can always go out-of-order or do a step again. If you do plan to sinter, I highly recommend a pass of trimming & shaping before the sinter, then further cleanup after.

Note: this is step 1 of a print / sinter / polish process.

This is a quick overview for how to print metal filaments in a "normal" 3D printer: Colorfab (Brassfil, Bronzefil, Copperfil), Proto-Pasta (composite SS, Iron, and Copper), and Virtual Foundry (Filamet in bronze, copper, cluminum) sell filaments with at least 50% metal content. Other "metal" filament with less content can be printed like normal PLA (or whatever base plastic) and is therefore less challenging.

Note: this is step 2 of a print / sinter / polish process.

I've spent sort a lot of time figuring out how to print and polish metals. Just because it's neat. There was a LOT of trial and error, and very little actual material I could find reliably, so I hope this log helps any others (or future me) reproduce the results.

3D Printed Fidget Spinners

I got these designs off of a site called http://www.thingiverse.com, where you can design templates and share them with the public, or download someone else’s. If you have a 3D printer, I highly suggest you use this site. I managed to find some designs and press the bearings and/or steel balls into them. Enjoy!

Shark fin spinner- http://www.thingiverse.com/thing:1936727

Triangular spinner-http://www.thingiverse.com/thing:2126470

Steel ball spinner- http://www.thingiverse.com/thing:1821445

Shark fin spinner Triangular spinner Steel ball spinner

Spinner w/ shark "fins" Spinner shaped like a triangle Spinner w/ steel balls for weights

Spinner model
Caps