I wrote a descriptive post on here for this very same problem and then deleted the post because I though I had fixed the issue only to find I didn't 10 minutes later.
I will only attach a image of the issue and the hip file to the project, I would appreciate it if anyone can teach me how to fix this issue.
I have a gap in my metal hoop(of the wooden barrel I am making in Houdini), I tried PolyCap, PolyBridge & PolyFill and none gave me the desired result.