Lightweight would be..in the extreme.. aerogel, just over two times as dence as air at sea level room temperature. It is also almost twice as expencive as a one way..ish trip to her majesty’s ship Titanic. It seems to be the best insulator we currently can produce and looks darn well amazing, almost ghost like in it’s rawest form.
Glass is not to heavy, pretty fire resistant and somewhat machineable if you have the right tool to fit a cnc. Glass sounds dull, but comes in so many colors mixtures and opaque shades, its prolly one of the more unique materials to be used.
Here’s a vid on creating a cnc glass cutting tool and using it. The tube is shot in a lovely phase with some hypnotizing shots of tool making and glass cutting.
There are some clay cncing vids, @Chucky_ott inspired to have a look into out there, but my tablet is acting up and makes it impossible to browse youtube. So I leave it with the glass one, I’m pretty impressed with.
The nice thing about these quirys is that I always get sucked into this rabhit hole and come out the other side with more questions I never knew I would want to look deeper into.
So thanks for this new perspective. It’s a fun out of the box river to meander on.