To get the Weldment Profiles to work, all you need to do is make a new part with a single sketch of the desired profile. A "good tip" is to include several points in the sketch to give yourself many options to locate the profile when you make Weldments.

1) Select the sketch in the FM and go to File\Save as Library feature part.

2) Now, save this or drag (requires folders to be have be made prior to draggin) this *.sldlfp into a folder that has a couple levels. For example, I made a folder called Custom Weldment Profiles/Extruded Aluminum/Inch/ and placed the *.sldlfp in the Inch folder.

3) No go to Tools\Options in SW and choose the File Locations category......then Weldment Profiles, then browse to the Custom Weldment Profile folder.

4) When you use the Weldment Tool, you will now see an additional Standard called Extruded Aluminum, a Type called Inch and a Size called whatever you named your *.sldlfp.

5) Of course, your folder names will differ, but the depth of the nested folders is VERY important for them to show up in the Command correctly.