Confused about Mesh to Brep in Fusion360

[reformy]

I've imported an STL file, and did "mesh to brep". The boy that I get is not a solid one, but an envelope (i think). Why is that?

[TheCADWhisperer]

Looks to me like you got 13 Solid Bodies and 1 Surface body.

Can you File>Export then Attach your *.f3d file here and end all doubt?

[I_Forge_KC · Accepted solution]

The result is a surface body. This happens when the mesh isn't actually water-tight (i.e. it has a hole in it)

You will need to go into the PATCH environment and use the stitch tool to look for any open holes. This might be simple... this might be insanely difficult... it all depends on what holes exist in the mesh file.

[reformy]

Thanks, but the other bodies are ones I've created with nothing to do with the imported stl.

[reformy]

Worked like a charm. Thanks!