You should be able to use this to cast aluminum. The original manifold you may have seen online was cast in brass. I have a big piece from Empire Robotics we hope to get cast in aluminium, just trying to find a vendor who’s interested in taking it on as a one off. Keep us updated on your results!
I’ve also been talking to a few people who wonder about using our original prototyping resin to produce a sand mold for casting rather than going through the investment process for something like aluminium.