Having just gotten a Qtip and dipped it in some lemon
juice, I swabbed the bottom of the positive contact. It pretty much dissolves the oxidation in seconds. Then I just wiped it off
First I chucked a small piece of white eraser in my drill and buffed the positive contact to remove any light scratching I had previously made in it using the fine grit. Then I chucked a longer piece of eraser in my drill and buffed the bottom of the battery tube.
Swabbed it with some lemon juice on a Qtip. Then removed the shavings. I had to use a rolled up paper towel to get them out and a little alcohol.
The mod hits better than brand new and that's hard to imagine.
So once that positive contact is buffed out, just a lil lemon juice makes it new. I tried it with the contact in place in my other one and it worked beautifully. I will remove it and buff it once the sunbox bottles arrive.
Thank you for the tips my German brother from another mother.
Next time I buff the bottom of the tube I will Chuck a pencil in the drill to make it easier.