DIY Telescoping Round Tube

[NRM]

I want to make some telescoping stands and am planning on using SS 1.25” Sch 40 pipe and SS 1” Sch 40 pipe. I have cut the 1.25” pipe to 4” lengths then cut them vertically with a .125” cut-off wheel and need to weld the pipe back together (see pictures). This will give me the tight tolerance I am looking for. The first 1.25” pipe I cut has a gap between .125” - .188”, and the second is .125”. I have read that people use copper as a backing for SS so my plan is to put some solid #4 copper wire on the inside of the 1.25” along the cut and weld the pipe back together. I need the inside of the 1.25” pipe to be smooth so the 1” pipe slides freely.

My questions are:
Does the copper and SS filler not weld together?
Does this sound like it will work?
If not any suggestions?



Thanks