Having trouble getting a model to render?

[Aquaileron]

I took a look at them and maanged to get them to render by using extrude to give them a little bit of physicality to them, it only has to be be minor, but to changes the mesh from triangle planes to prisms and the renderer picks them up

Can you tell me how you did this? I need to do this to all of the other Vib-Ribbon models I've ripped