Topband: Soldering aluminum coax shield to copper wire

[Chuck Hutton]

Many many years ago I had partial success soldering aluminum coax shield to copper wire using the motor oil technique. I also believe I had some flux (unknown type) that helped.
But I had no luck with motor oil last week and can not find the flux I had, which might be a good thing as it is 20 years old.

So what is the easy reliable cheap method to get the job done?

Chuck