1. Welding along intersection:

   - select 2 objects in object mode,

   - choose what type of weld you want to place (Geometry/Decal)

   - click "Weld" button

   - adjust scale by moving the mouse (LMB to apply, RMB sets to default scale)

   - adjust rotation by moving the mouse (LMB to apply, RMB sets to default rotation)

2. Welding along edgeloop:

   - select desired edgeloop in edit mode,   

   - choose what type of weld you want to place (Geometry/Decal)

   - click "Weld" button

   - adjust scale by moving the mouse (LMB to apply, RMB sets to default scale)

   - adjust rotation by moving the mouse (LMB to apply, RMB sets to default rotation)

3. Drawing:

   - click "Draw" button while in object mode

   - draw on the model's surface 

   - click RMB or Enter in order to finish drawing and place weld   

   - adjust scale by moving the mouse (LMB to apply, RMB sets to default scale)

   - adjust rotation by moving the mouse (LMB to apply, RMB sets to default rotation)

4. Profile editing:

   - select weld,

   - click "Modify" button

   - adjust weld's profile by playing with curve widget

   - click "Apply" button to accept results