[killernoodle]

A mold can be made much easier than a waterblock because of the ease of clay to mill. You can actually use normal modeling clay, put it in a kiln to dry it, put that on a cnc machine or a mill, and grind out the negative of the waterblock. This would be easier on the radius because the pattern of the fins is more adept for milling than the channels would be. If they do not carry end mills that are the correct size, I believe dremel sells some for tile that would work perfectly. I might make something like this to test the theory, but I cannot melt copper with the stuff I have to work will so maybe lead or tin will have to do for a model of the process.

I believe Thermaltake uses casting for their waterblock for the aquarius (sp?) and, if I'm not mistaken, the top of the silverprop evolution all copper one is cast.