I made these little holder thingies to support the flatwork. Seems to have worked. I was able to do a tighter wind and pile some wire on there without having to worry about the bobbins flaring out.
The cardboard soaked the CPES up and hardened pretty nicely, but probably should have done like Bruce suggested and coated them with West first. There’s a couple of spots where the acetone may have dissolved the CA glue. They won’t come apart at this point, but applying epoxy would be one extra step I could take to ensure that they hold together.
Next, I gotta make a new mold to cast the bobbins in.