Hello there,
I’ve got this situation whit some solids
Can I merge/combine solids each other filling remain holes?
So, I’ll just obtain one solids
Hello @stemilan96 …I would try to find the perimeter curves and create a solid by loft as it seems you already have tried…if you want then share your files,you know everything can go wrong 
i tested your case with with 3dm demo file… … it works to get the form. So working with all kind of geometry should work!
