[TheForge] repairing tapped sleeve

[theforge@mailman.qth.net]

I have some machine parts that need to be repaired. They consist of a steel 
sleeve that has the inside threaded to 5/8 NC and the wall of the sleeve is 
worn completely away in some areas. I can cut out the sleeve and replace it 
but that will be real pain in the neck. I tried to find some carbon rod that 
I could thread and screw into the sleeve and then build up the wall with 
weld. I haven't found any carbon that will work. I wonder if a copper rod 
will work?  I looked at copper rod in the McMaster Carr catalog it shows a 
melting point of 1981 deg F. I'm afraid that's too low. Any ideas? 

Thanks in advance, Dan Cruzan