This is how you create a solid protrusion from a surface:
1. create the surfaces
2. Make sure the surfaces you've created completely enclose a space (you can't have any openings)
3. Create a surface merge feature. You may have to do this two surfaces at a time until you have a surface merge of the entire set of surfaces.
4. Then edit>solidify in Wildfire and you have a solid protrusion.
From that point on, you can edit dimensions, add cuts or other protrusions, or whatever.