By tradition, graduating high school students in Denmark carry a special flat cap with a badge on front pertaining to their school. The company C.L. Seifert aggressively markets their caps to students by hosting hat-fittings during school hours and presenting themselves as the only option. While the company doesn’t have any exclusive rights to make these hats, they have a practical monopoly on them and are making mad cash charging from around 600 dkk (~100$) to 1200+ dkk a hat (Edit: It seems they also make cheaper hats. Point still stands, they’re not a nice company). Not my thing.

I at first wanted to make a direct copy of a hat to show why their price tag is absolutely ridiculous. In the meantime my mom had gotten into felting. Why not just point a finger at the tradition itself and make a felted wizard student-hat? Same shit. To draw a direct parallel, I still wanted the hat to have a badge.
Two easy options could be to steal a random badge from somewhere or just 3D print one and spraypaint it metallic. What about actually casting a badge? Seems doable.

I wanted to cast in tin or a tin alloy, as tin has a low melting point and is mostly non-toxic. I went to the local thrift shop and found an old pewter cup with an ‘English Pewter’ stamp on the bottom. Turns out this means it’s lead free, which is nice thing for your far too concerned relatives to hear. While I had no way to measure, it also seems like this alloy has a relatively low melting point which also is quite nice. I cut it into pieces and melted it in a small container of stainless steel I also found at the thrift shop. I spent some time getting to know how hot liquid metal behaves and how to handle it. The final procedure i ended up with for readying the metal for a pour is as follows: Dry and heat the mold in the melting cup. Melt an excessive amount of the metal. Add a small amount of soldering grease to make pouring easier. Skim the surface and bottom with a steel tool or wire to remove impurities. Pour in the mold continuously, starting from the thinnest part of it.

The pewter cup stamped with "English pewter", cut and melted down

To make a mold I first 3d printed a positive. I considered using normal molding-sand, but decided against it after seeing the price and limited availability. Instead I went to the hardware store and found some temperature resistant silicone. The stuff I found seems to be designed for ovens or something but whatever. It’s rated for 300 C and has behaved nicely so far. I covered the positive in petroleum jelly as a makeshift release-agent, drowned it in silicone and let it dry, peeled it off with much difficulty and patched holes and thin areas. It’s quite a mess, so do it in something disposable and don’t expect the positive to come out clean.

3D printed positive and its mold.

Pours had a tendency to not fill out the mold completely, although using soldering grease helped a bit. If you’re designing your own mold, stay away from thin shapes. Surface details come through nicely, which also means sanding or filing is necessary to remove the 3d printing artifacts. Air bubbles don’t seem to be completely avoidable. I find them kinda charming.

Badges

I ended up doing around 10 pours before making a badge I was happy with. I filed it down and soldered some mounting pins to the back side with solder and a gas torch. The badge is mounted on the hat with a rosette made of cassette tape. It seemed fitting ;)

Pic of the final hat

Update: Made another small badge for my backpack.
Pic of a small badge hanging from a string Next up, something less 2D?