How to "smelt" Vectors?

[SHack]

Hello!

Is there a way to "smelt" vectors? Combine will not do the trick. i want to smelt 2 rings but it won't work. 

I want these 2 rings to be one curve, but... see yourself:

Thanks for any advice!

[NotMyFault]

It works for me with this process, using geometry->add:

1. activate grid
2. create donut shape, hole radius 75%, size and position matching grid
3. duplicate
4. move one to perfectly match position 
5. convert to curve
6. geometry->add

the donuts create only 4 nodes per circle.

Depending on multiple factors (number of nodes, position and orientation of start nodes) it could work or fail to add those circles.

[SHack]

It can be so easy... thank you so much!