How do I "weld" a uniform b-spline when weld doesn't work?

I'm drawing wavy lines that I need to edit once draw. They don't draw well in arc or bezier curve. I can get the exact shape I want with the uniform b-spline. Do I need to convert the line into something else once drawn? I need the line to be very smooth as I'm sending it to a cnc machine. I need to pull the parts apart in groups eventually. It would be nice not to have to sit and click on every little line segment in order to copy and move the part over.