I know this question has been beaten to death, but I have tried all the solutions, and none of them work (manifold, normal's, triangulate, splitting it into simpler parts)
Im trying to add hoses to the side of my model, but the union boolean isnt working properly. It just makes the part disappear. Once I join them, I can mirror the part.

I did import these models from starcraft 2 using a m3 import tool, so there may be something a bit more complicated going on here that I just dont understand.(vertex groups? Materials?)
heres the file: http://pasteall.org/blend/index.php?id=43732 (the entire model is there, just hide everything but the hips/hoses for now!)
Thanks for the look!


