My next project silver/gold pens, the pictures are the art work on the wax cap tube,next is building Vaccum casting machine
Itzak - You might also take a look at Bill Struve's new sterling silver precious metal clay (PMC) - called EZ960 - here: https://www.youtube.com/watch?v=xQhEgQm1SHE
I just got some for jewelry making, and will soon be using it in pens - Cool Tools ships internationally - here's the link:
https://www.cooltools.us/EZ960-Sterling-Silver-Clay-p/ezs-025-p.htm
I'll be firing it to the required 1635 degrees fahrenheit in my little enameling kiln.
Since the shrink rate is 10-11%, it would be interesting to roll it out to about 3/64", wrap it around a wooden (or other burnable material) dowel, kiln-fire (2hours), then see if you get a tube or something workable. I can picture a nicely detailed sterling silver serpent wrapped around a burnable mandrel, which can then be wrapped around a real tube after firing - just add rhinestone or cubic zirconium eyes and some attitude...
I think the EZ960 clay can also complement your casting if you go these parallel routes - easier to work the clay than it is to work wax; but both are fine techniques.
Warm regards, and have fun - Bob
(And thanks, Mark!)