I am trying to cast a "shuriken" out of aluminum and am having some issues with creating the sand mold.
Here is the pattern I am trying to copy:
I made a print out of the picture and pasted it to a small piece of wood. The wood is about 1/4 inch thick. I then used a band saw to cut the pattern into the wood. The shuriken is about the size of the palm of my hand. I didn't try to make the sharp edges on the template (well I did, but the edges kept breaking at odd places ruining the template). And even if I did, I figured that would make the mold even harder to create. Once the shuriken is made, I can always use a sharpening stone, metal grinder, or Dremel on it.
The arrow shows the area I am having trouble with the mold.
The sand in these cut outs stick to the template instead of staying in the mold. I put a good amount of parting powder in the cut outs, but that didn't help.
Anyone have any suggestions how to fix this. I was thinking the wood itself was the issue, so I am thinking of trying to tightly encase the shuriken template in plastic wrap, or maybe a thin coat of polyurethane. I also thought about not worrying about the cut out and machining them out, but that seemed like a lot of extra work and I am not sure I have the necessary tools - other than my Dremel.