Target Weld

Support Modeling
3
  1. Enable AutoMerge Editing (Mesh -> AutoMerge Editing, there’s also a button for it in 3D view header),
  2. Enable snapping and set snap type to Vertex,
  3. Tweak a vertex (select-drag it),
  4. Put it on a target vertex (it’ll snap once mouse pointer is close) and left click,
  5. Repeat 3-4 to satisfaction.