[Rhodes22-list] is there a metallurgist in the house?

[Joe Babb]

Ok, this is not about sailing, but I'm hoping there is someone on the 
list that can help me out with a metal lubrication problem.

I work on steel guitars and most all of them have what is called a 
changer where aluminum parts ride on a steel shaft.  The range of motion 
is very small, but there is lots of pressure as the strings are curved 
around the aluminum.  There is usually lubrication between the steel and 
aluminum.  I've seen some sort of grease used and most folks recommend 
sewing machine oil or gun oil.  But over time the lubrication gets 
gummed up and/or the aluminum "appears" to gall (like when you file 
aluminum it loads up the file) and scores the steel shaft.  This results 
in a sticky action.

What is a good lubricant to use between steel and aluminum?   Does 
sewing machine oil mix with grease?  For instance, if grease is used 
originally and someone uses oil later will it still be good lubrication 
or will it gum up?
Joe