Brazing steel lines with a copper conector

[rainbowvend]

I am working on refurbishing an Ideal 85 slider.  Lots of fun!  I have a hole in one of the steel lines that needs to be repaired.  I would use a copper connector after cutting the steel line.  What solder should I use to finish the project.  Also, what size modern compressor should I use as I have to replace one on another unit I have on my bench.  Looks like I will have to fabricate some brackets to use a modern unit once the old unit is pulled out of the system.  
Thanks for your assistance!

[johnieG]

You'll need a low phosphorus 5-10% silver bearing braze rod & the appropriate flux paste, "Stay-Silver" makes a nice line of rods & fluxes, replace the line, just don't fix the pin-hole.  be careful not to overheat the copper (it will melt or oxidized severely) while getting the steel line hot, once the steel is a dull-red, it's more than hot enough to flow the brazing on the copper

[cohammer]

I always use flux coated rod you can read on the pack and make sure you get the proper rod . It takes a little pratcice to make a proper connection .

[globalcompressors]

zero percent rod and stay-silv paste

[Yarochrehc]

I always use silver solder and paste flux any time I have to solder copper and steel or stainless.