I was playing around with some casting supplies and molds that I made recently. The molds are printed on the Makerbot... I wanted to try a new technique I have been thinking about.
I have been looking at the 3D sand printers online quite a bit. It is amazing how the hardened sand blocks fit together snugly and they are able to get very good looking castings from their process.
So, I thought maybe I could duplicate this with a "mold for a mold" that I could fill with hardening core sand and then glue the two pieces together to make a mold. Heck, that could even work for low volume production needs
Close, but no ceeegar. The regular white silica sand that was used is too large of a grain to really get the surface finish right on the parts. I think the sides of my mold having lines from the makerbot made it a bit tougher to pop out the hardened sand block (even with 5 degree tapers).
I also packed in some green sand (yes, I know it's brown) and the surface finish was excellent. This was really just to see what it was like... and compare the two options. Obviously, the green sand was not able to be handled, but the hardened core molds were.
I may look for a finer grit of sand and try the core mold process yet again. Any input from he group would be appreciated... I know a lot of you have more experience with casting than I do.