I have a surface model that i mirrored and then knit the two halves. It Shows no gaps and when I choose the check box to form a solid and click ok, it finishes and the part moves from the surfaces folder at the top of the model tree to the solids folder. When I look at it from a section view, it is still a surface. Nothing has any measurable thickness to it. I am at a loss. Normally you fight with the surfaces, closing all the gaps and then it will finally work, and it won't form a solid until it can. Any ideas?