Up front public service announcement - I use all this for the duplication of custom parts and one of a kind projects or other special stuff - if anyone out there is considering this for a "cheap" way to get any existing available gw
part (melta's, grav weapons) it is MUCH cheaper and easier just to buy them (or get the bits on ebay) - casting is time consuming and getting good at working with complex parts or molds (the shape of the master can dramatically affect the complexity of how the mold must be made) is an art. Again, not accusing anyone of anything, or implying - just sharing information - especially if someone else is reading this thread and thinking this is a way to get cheap or free parts.
Is there such a thing as a vacuum/pressure pot for amateurs without incredibly thick wads of cash? I've been considering doing some resin casting for my class projects but am a bit lost on how to go about it right. It seems a lot different than the processes taught to me in my art metals and metal casting courses.
This was mostly answered already, but I can throw in my thoughts as well, as I do a lot of fabrication and casting (not just for gaming, but I have a lot of friends who do work with a friend on special affects/props and fabrication).
As suggested above, my pressure pot is just a painting pressure pot from harborfrieght, I think with one of their "super deal" coupons, it was about $70.
I got a vacuum chamber (for degassing silione - again, as mentioned above...) off ebay, for less than $100 and its very good quality and has lasted me for years.
I got an affordable vacuum pump at harbor freight for about $100.
Mostly I make terrain (I LOVE making custom bases, its a very fun project) or vehicle parts or odd sculpts (I had to make a bunch of hutt's for a star wars project once) but I have not tried shoulder pads (I need some custom pads for my custom chapter) - as my sculpting skills are not very precise, I am considering 3d printing my master, and casting those up (I need about 60 of them).
There are a lot of other posts on here on casting, but to be honest check out some of the other dedicated casting resources out on the net - resin addict is a really good one.
best of luck and have fun!