Rust removal on flat double cut bastard file

[Mike Perez]

What the easiest way to removed the rust?
Hand sweat keeps getting it rusty.
Thank you,

[Peter Wilcox]

I've never had that problem, but I'd think a file card would clean most of the rust between the teeth, and just filing a piece of steel would get it off the tooth ridges if needed.

[Jim Ritter]

I’ve soaked files is household vinegar, depending on how much rust you are dealing with a couple hours to over night brush with a brass brush after a couple hours as a test. When finished rinse with hot water, dry immediately with a paper towel and heat gun. I resurrected a bunch of Swiss pattern needle files that way, they were trash otherwise.
Evaporust is an off the shelf product that will also work but at a much higher price point.
Try the vinegar on some other rusty thing first just to get the feel of it.
Jim