Join parts for 3D printing

Hi everyone… I’m a beginner with 3D modeling and with Blender…

I should join two solids for 3D printing scheme on one side the line that divides them and on the other hand close it and stick them together. One thing like in the picture …

I tried with a half cylinder but I would need something more practical and faster that can follow the dividing line …

Can anyone advise me?

Thanks bye!

Hi, Iam little bit confused with the image and how you want to joint it there. In general I would advise booleans with some retopology repairing, or joint the two object and use voxel remesh.

Could you show us more of your mesh? This screen shot doesn’t really show anything helpful.