Metal Casting Zone

Hey all, first off this is my first post on this great site, so thanks for any and all insight you can give this newcomer!

I am looking to cast a small and slightly intricate (think of a cross with a ring passing through all four axis's) pendant out of silver/sterling silver. I am quite new to the casting processes, and as far as I can tell, for a college student, the sand casting is the most economical and cost effective method. I have two questions. The first is, after preparing a model of the pendant, in wax/wood/plaster, would it be possible to use a one sided cast? By that, I mean a sand cast open to the air and poured directly upon (or in a pour channel to be exact). Normally, all I have found are examples of people using the method I just described but adding another half that is merely the backing of the piece, but in sand. With such a delicate design, such a one sided method strikes me as easier and less likely to break the design with piecing together two sided mold. Any advice here? The second question is for any suggestions for a sand mixture that holds strong and is smooth enought to retain a smoothable surface?

Thanks again for all the help!

well for starters would love to see what you have in mind for an idea. ok now on to your questions. An open face mold does not work all that well for small items because you can not get any head pressure up to get the metal to push into fine detal.
I would recommend making a purchase of some petrobond sand as it gives good detail on small items but if you have alot of fine detal you should consider lost wax casting.
also for a good material to carve your project out of try the ferris file a wax "hardest" it can be cut with a jewlers saw filed sanded carved real easy stuff to work with.

Thanks so much. I am a bit confused with your wording about the carving material, are you suggesting a "ferris file wax" (the "hardest" type of it)? And I have given Lost Wax a thought, but it sounds like a centrifuge is necessary? Can you simply melt out the wax and then pour in the metal using gravity to fill the cavity. I've included a picture of my design with the post. Image that the line has been stretched horizontally to give it width. I hope to somehow fit a gem (princess cut I believe) into the center of the "butterfly/cross." I used my previous description just to give a mild degree of complexity, not really knowing how to describe this particular design. And one last thing, would you suggest making a master out of hard wax, then duplicates using a replicating method out of softer wax to melt in a lost wax mold?

Thanks again for all the help, I'd be wandering aimlessly without your generosity lol!

*I used google and figured out the carving material issue! Thanks, looks like the green "Ferris File-A-Wax" might be the way to go. Still unsure about the physics of a lost wax mold without a centrifuge though.

I did a lost wax rose with head pressure only, it didn't fill completely.
www.metalcastingzone.com/metal-casting-forum/lost-wax-casting/lost-wax-rose
With lost wax you can use head pressure, steam casting, Vacuum casting or a centrifuge. I've only tried the one thing so far but for a small jewelry item I imagine you'll need steam, vacuum or a centifuge.
Google "Jewelry Casting" or "Lost Wax Casting" under videos.